Arctic Sea Ice : Forum

Cryosphere => Permafrost => Topic started by: Neven on March 07, 2013, 11:24:11 PM

Title: Northern Hemisphere snow cover
Post by: Neven on March 07, 2013, 11:24:11 PM
Okay, so I added 'snow cover' to this board's subtitle, just so I would have somewhere to put this. Al Rodger wrote a great guest piece (http://neven1.typepad.com/blog/2012/08/the-untold-drama-of-northern-snow-cover.html) last summer for the ASIB explaining why snow cover is important, and how its summer decline is at least as important as that of Arctic sea ice.

This year's February anomaly comes in lower than the previous three years:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimate.rutgers.edu%2Fsnowcover%2Fpng%2Fmonthlyanom%2Fnhland02.png&hash=ca044f6cf0c15dbde2a7834bbd843074)

Graphs comes from Rutgers University Global Snow Lab (http://climate.rutgers.edu/snowcover/index.php).
Title: Re: Northern Hemisphere snow cover
Post by: Juan C. García on March 12, 2013, 03:16:36 AM
It will be interesting to see if we will have a new snow cover anomaly record at June/2013. The last five years were of impresive anomalies and of course, it has a relation with the permafrost and methane emissions, even that I would say that there is not good measurement of methane emssions related to the thawing of the permafrost.

(image also from Rutgers University Global Snow Lab:
http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6 (http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6)
Title: Re: Northern Hemisphere snow cover
Post by: ggelsrinc on April 02, 2013, 03:49:59 AM
It will be interesting to see if we will have a new snow cover anomaly record at June/2013. The last five years were of impresive anomalies and of course, it has a relation with the permafrost and methane emissions, even that I would say that there is not good measurement of methane emssions related to the thawing of the permafrost.

(image also from Rutgers University Global Snow Lab:
http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6 (http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6)

I've been using the same chart to paint a picture of what will happen if this trend continues. The June anomaly doesn't have to increase, it's magnitude is already at three times the area of Greenland or the remaining arctic sea ice at minimum. I picture a large NH area having air masses warmed by the albedo change during the most direct times of sunlight. I think those Greenland melts are going to become much more usual and hope it will motivate governments to show their proper concern about climate change. Afterall, Rip Van Winkle only slept for 20 years.
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 07, 2013, 12:09:10 PM
March ended up a positive anomaly:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimate.rutgers.edu%2Fsnowcover%2Fpng%2Fmonthlyanom%2Fnhland03.png&hash=47e5a73d94fc9dc816659996826537f1)

It will be interesting to see what April does, no positive anomaly in 9 years:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimate.rutgers.edu%2Fsnowcover%2Fpng%2Fmonthlyanom%2Fnhland04.png&hash=a3d362a7f454569b2f07045a238ed58a)
Title: Re: Northern Hemisphere snow cover
Post by: ChrisReynolds on April 07, 2013, 12:13:35 PM
Eurasian snow retreat in May is leading to warming and this early start to the melt season is occurring over major areas of permafrost. That latter point is missing from my blog post, but I thought my readers would be all too aware.
http://dosbat.blogspot.co.uk/2013/03/eurasian-snow-cover-and-atmospheric.html (http://dosbat.blogspot.co.uk/2013/03/eurasian-snow-cover-and-atmospheric.html)
Title: Re: Northern Hemisphere snow cover
Post by: crandles on April 07, 2013, 01:36:42 PM
March ended up a positive anomaly:

I am sure that is true but at the moment graph says it runs to 2012. I guess that is one way to appear to be first to post on release of graph. Or did graph update and then revert?
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 07, 2013, 08:47:31 PM
I am sure that is true but at the moment graph says it runs to 2012. I guess that is one way to appear to be first to post on release of graph. Or did graph update and then revert?

I just looked at the bars and it looked to me like the 2013 bar was there. At the top it says 1967-2013 as well. We're talking about the March bar graph, right?
Title: Re: Northern Hemisphere snow cover
Post by: crandles on April 07, 2013, 09:17:41 PM
This is what I see above and when I go to site and control-F5.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Ffarm9.staticflickr.com%2F8247%2F8628032923_d395fdab68_z.jpg&hash=f88293332cff57aa0b02d7d8152ff1d8)

Says 1967-2012 March at top and last bar is negative.

Control-F5 should clear any cache and download it again shouldn't it? Am I looking in wrong place? I'm confused.  :(

Edit: sorry ignore me. Control-F5 didn't make a difference but tried a simple reload of the page and it worked. Shows above too now.
Title: Re: Northern Hemisphere snow cover
Post by: Artful Dodger on April 08, 2013, 11:06:43 AM
Snow cover over sea ice is an important, under-reported measure during the dark cold Arctic Winter.

Snow is an excellent thermal insulator. When snow covered, sea ice attains thermodynamic equilibrium with the atmosphere when it is much thinner than bare sea ice. Alternatively, snow-covered sea ice will grow to the same thickness only if the atmosphere is much colder.

We know from the 80N temperature plot this Winter that the atmosphere WAS not much colder, in fact it was warmer than normal except for the period spanning Feb/Mar with high winds, which tends to scour the surface of warm air by mixing in higher colder layers.

Additionally, the Feb/Mar break-up event itself argues that the sea was not as strong as in past years, which may indicate that it's thickness was reduced.

Two important results will come out in May. First will be the report from NASA Icebridge, which flew at least two missions over the Beaufort sea in late March. Second is the scheduled public release of AMSR2 Level-2 data, which includes 'Snow-over-sea-ice' data.

Looking forward to this analysis since I think it will be quite useful for prediction as the 2013 melt season progresses.
Title: Re: Northern Hemisphere snow cover
Post by: Artful Dodger on April 08, 2013, 12:04:06 PM
...the period spanning Feb/Mar with high winds, which tends to scour the surface of warm air by mixing in higher colder layers.
Since this is a related topic, I want to highlight some recently published science:

Sterk, H. A. M., G. J. Steeneveld, and A. A. M. Holtslag. "The role of snow‐surface coupling, radiation, and turbulent mixing in modeling a stable boundary layer over Arctic sea ice. (http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50158/abstract)" Journal of Geophysical Research: Atmospheres (2013).

There is also a freely-available PDF (http://www.met.wau.nl/medewerkers/steeneveld/Sterketal2013.pdf) for interested readers.

Now, an excerpt from the Abstract:

Quote
Keywords:
  • Arctic stable boundary layer;
  • modeling;
  • GABLS;
  • turbulent mixing;
  • surface coupling;
  • radiation
Results indicate a shift in process significance for different wind regimes. For low wind regimes, the model sensitivity is larger for surface coupling and radiation, while for high wind speeds, the largest sensitivity is found for the turbulent mixing process. An interesting non-linear feature was found for turbulent mixing for frequently occurring wind speeds and low wind speed cases, where the 2 m temperature increases for decreased amounts of mixing.

So it seemly likely that decreased 80N surface temps during Feb/Mar 2013 were the result of enhanced wind-mixing of the surface layer with colder higher air.
Title: Re: Northern Hemisphere snow cover
Post by: Apocalypse4Real on May 26, 2013, 07:28:25 PM
The Siberian snow drought is apparent in the Rutgers and Drought Monitor imagery.

Attached are the Rutgers Snow and Departure from norm for May 25 2013, and the Drought Monitor for Siberia as of May 16, 2013.

Very warm air continues to flow north over Siberia for the next 5 days.
Title: Re: Northern Hemisphere snow cover
Post by: Apocalypse4Real on May 26, 2013, 07:56:04 PM
Here are two better perspectives for the UCL drought data, that help make the snow drought glaringly obvious for the Northern Hemisphere:

Attached are the Euro-Asia, North America and Arctic 90 day drought levels as of May 16 2013
Title: Re: Northern Hemisphere snow cover
Post by: Neven on July 08, 2015, 07:56:03 AM
Nightvid Cole posted in a separate thread:

NH snow cover for June is second lowest on record

See chart. (Note: This only includes land snow, not snow on sea ice, so this is a separate measurement from the very low June snow seen on sea ice this year).
Title: Re: Northern Hemisphere snow cover
Post by: Jim Hunt on July 08, 2015, 09:50:56 AM
Certain "skeptical" sorts would have us believe otherwise:

http://GreatWhiteCon.info/2015/06/alaska-may-snow-cover-at-record-low-levels/ (http://GreatWhiteCon.info/2015/06/alaska-may-snow-cover-at-record-low-levels/)

Nightvid & Vergent get a mention!
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on October 19, 2017, 09:26:50 PM
I could n't see a more recent thread, although I am sure NH snow cover crops up regularly in other threads so I've resurrected this one.

Kind of surprising there is n't more about this topic. As the NSIDC put it "in terms of area, snow cover is the largest single component of the cryosphere, covering an average of about 46 million square kilometers (about 17.8 million square miles) of Earth's surface each year ."

Interesting to look back on some of the posts from the start of this thread or indeed prior to that in this blog five years ago from Neven (http://neven1.typepad.com/blog/2012/08/the-untold-drama-of-northern-snow-cover.html).

In recent years the lack of snow cover was especially evident in the crucial late spring/early summer period.

"At the height of this summer's melt, 2012 was 8.5 million sq kilometres ahead of the 1972-1979 average. This is a full month advance in the melt over a 27 year period."

So here is an update from Rutgers University. 2017 is turning out to be a snowy year. I've put it alongside 2016 for comparison. 2016 was much like the years prior showing serious decline in snow cover. 2017 has seen quite a turnaround. Most months so far with positive anomalies and the negative ones were only slight.

The question is, are we seeing a shift in the climate of the Arctic, a change from a once desert climate to a more snowy one. Will the warming world lead to more snow in the Arctic ? Or is this recent change only a blip ? 

Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on November 04, 2017, 04:35:42 PM
I could n't see a more recent thread, although I am sure NH snow cover crops up regularly in other threads so I've resurrected this one.



I know you have a particular interest in this topic (I find it interesting myself as increased precipitation is an expected response of climate change.) Posting here is the right thing to do and, if you continue to use this thread, it will remain active and draw more visitors.

Question....hasn't there been a trend of increased earlier NH snowfall over the past decade? I remember someone posting this but cannot remember where.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on November 14, 2017, 06:20:27 PM

Question....hasn't there been a trend of increased earlier NH snowfall over the past decade? I remember someone posting this but cannot remember where.

All the months from September through to January show a positive trend for monthly northern hemisphere snow cover (1967-2016). You can check out the plots here (https://www.ncdc.noaa.gov/snow-and-ice/extent/snow-cover/nhland/9) for each month.

For the other months there is a negative trend. This year continues to see mostly positive anomalies.

For October 2017 the NH snowcover was 21.17 million sq km. (+3.63  above the 1981-2010 norm).

A little bit less than October 2016. This being the first month that 2016 had higher anomaly than 2017.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on December 18, 2017, 11:45:34 PM
NH Snow cover extent for November 2017 continues in same vein to the previous 8 years, with another positive anomaly.

+2.01 million km2. A little bit less than last year's high value.


Title: Re: Northern Hemisphere snow cover
Post by: Neven on December 19, 2017, 12:02:34 AM
It's third lowest according to NOAA's Automated Multisensor Snow/Ice Mapping System.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on December 19, 2017, 09:16:23 AM
It's third lowest according to NOAA's Automated Multisensor Snow/Ice Mapping System.


Yes, that NOAA chart shows a bit of a dip in extent for December. , when the December figures roll out I expect Dec 2017 will be lower than last year, especially given the conditions over North America this month.

I would be surprised if the NOAA graph is any much different to the Rutger's graph.

But I find the NOAA graph gives too short a time span. For climatology you need  a (preferably)recent  30 year period. Rutger's does provide that, and shows the changes that have taken place back to 1966 or thereabouts. (graph attached is for month of November)

When we look at sea ice extent graphs we look back to the start of the satellite era circa 1979. Why should we do any different for snow cover ? 
Title: Re: Northern Hemisphere snow cover
Post by: Neven on December 19, 2017, 09:50:11 AM
I agree and didn't mean to contradict you. Your post just prodded me to have a look at the Multisensor graph. It may not be as 'mild' as last year, but there has also been less snow so far (not so many storms coming in from the Atlantic).
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on January 02, 2018, 01:27:55 PM
Agree that for Eurasia it has not been as snowy this December.

I saw a report that Moscow had no lying snow recently and they rang in the new year under rainy/grey skies.

Here is an interesting report from Dartmouth College : Warming seas double snowfall around North America's tallest peaks.  (https://www.sciencedaily.com/releases/2017/12/171219091058.htm)

I wonder when/if this would transfer into glacier growth ?

Extract: "We were shocked when we first saw how much snowfall has increased," said Erich Osterberg, an assistant professor of earth sciences at Dartmouth College and principal investigator for the research. "We had to check and double-check our results to make sure of the findings. Dramatic increases in temperature and air pollution in modern times have been well established in science, but now we're also seeing dramatic increases in regional precipitation with climate change."

According to the research, wintertime snowfall has increased 117 percent since the mid-19th century in southcentral Alaska in the United States. Summer snows also showed a significant increase of 49 percent in the short period ranging less than two hundred years.


Title: Re: Northern Hemisphere snow cover
Post by: Neven on January 03, 2018, 10:49:17 PM
NH snow cover interesting right now:
Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on January 03, 2018, 11:38:15 PM
Interesting?
I call that depressing.

We tried to do our part: a few flakes of snow fell this morning here in Tallahassee!
Title: Re: Northern Hemisphere snow cover
Post by: Bernard on January 04, 2018, 12:34:07 AM
Agree that for Eurasia it has not been as snowy this December.

I saw a report that Moscow had no lying snow recently and they rang in the new year under rainy/grey skies.

Here is an interesting report from Dartmouth College : Warming seas double snowfall around North America's tallest peaks.  (https://www.sciencedaily.com/releases/2017/12/171219091058.htm)

I wonder when/if this would transfer into glacier growth ?


Here in French Southern Alps we had quite a lot of snow in December 2017, whereas December 2015 and 2016 had been completely dry. But it comes with brutal temperature changes. On December 10th we had about 50cm (at elevation 1000m) starting to fall in the morning at an amazing low temperature (around -10°C), and the day after it rained all day on this deep and cold snow, turning it into a nightmare of ice. And today we had wind and rain up to more than 2000m at the southern edge of Eleanor, the strongest (so far this winter) of a series of winter storms.
This kind of weather had become frequent. Instead of a good quiet snow fall followed by stable and cold weather for weeks, snow comes in the form of storms and with rapidly changing temperatures. Globally, more snow might fall, but it's not here to stay all winter long as it were. Most ski resorts in France use artificial snow to ensure all-winter opening (at a silly cost in water and energy).

The impact on glacier might be more accumulation at high altitude. But it does not prevent the ablation zone to climb higher and higher in summer, and the global yearly budget to keep steadily negative.

See e.g., for an emblematic glacier next to my place
https://en.wikipedia.org/wiki/Glacier_Blanc
http://www.ecrins-parcnational.fr/actualite/forte-perte-estivale-glacier-blanc (in French, but you get a graphic)

BTW I should certainly open a new thread about it, but my wish for 2018 for this forum would be to see it enforce the use of the International System of Units, as any respectable scientific forum should, and stop using units from the pre-scientific era such as square miles, feet, gallons and unameit.  :(
Title: Re: Northern Hemisphere snow cover
Post by: Sleepy on January 04, 2018, 09:06:38 AM
I wonder when/if this would transfer into glacier growth ?
Current warming won't allow glacier growth any time soon, maybe in ~50000 thousand years or so, according to the Astronomical CLimate Index.
Red is past/thousand yrs, blue is future/thousand yrs. Bottom curve is sea level.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on January 04, 2018, 11:43:06 AM
NH Snow cover figure for Dec 2017 was 43.57 million sq km. This is a little below the 1981-2010 average. Much of the deficit was in Eurasia.

Anomaly of -0.41 million sq km.

This completes the anomaly chart for 2017.
Title: Re: Northern Hemisphere snow cover
Post by: RikW on January 05, 2018, 10:03:46 AM
Last year I've seen people say that the high snow-cover (more snow leads to more evaporation leads to more clouds during summer leads to lower temperatures during summer) could be a possible explanation for the lower melt during summer.
And also for the lower ice-growth during freezing season?

Though it's a little too early to say anything about how the snow cover will be in the coming months, could this lead to a better freezing season and a worse melt season?
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on February 07, 2018, 09:43:00 PM
The NH snow cover figure for Jan 2018 from Rutgers Lab has come in at 46.93 million km2

This is above the 1981-2010 average by just a small margin (+0.065). It is approx 2 million km2 less than 2017 and 2016 figures.

Snow cover over Europe,  southern parts of Asia, western USA was below normal, whereas it was above normal over China and the far East and northern US Plains
Title: Re: Northern Hemisphere snow cover
Post by: Neven on February 07, 2018, 10:04:14 PM
Thanks for this, Niall. Here's the Rutgers NH snow cover anomaly bar graph for January:
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on February 07, 2018, 11:19:42 PM
And this is what Environment Canada say

https://www.ccin.ca/ccw/snow/current
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on February 19, 2018, 11:59:23 PM
And this is what Environment Canada say for 18th Feb 2018

Note that extent is beyond the peak, but snow water equivalent not;
Note also that extent is sort of average, while snow water equivalent is really high.
Thick snow ?

https://www.ccin.ca/ccw/snow/current
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on February 20, 2018, 01:17:52 AM
Heavier wet snow which would become more common as temps rise?
Title: Re: Northern Hemisphere snow cover
Post by: prairiebotanist on February 20, 2018, 01:28:42 AM
Heavier wet snow which would become more common as temps rise?

...or if other locations are like mine (SE WI, USA), cold rainfall into an existing snowpack can really ramp of SWE even as the depth of that snowpack slowly decreases, and winter rains also become more common as temps rise.
 
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on February 20, 2018, 03:39:19 AM
Heavier wet snow which would become more common as temps rise?

...or if other locations are like mine (SE WI, USA), cold rainfall into an existing snowpack can really ramp of SWE even as the depth of that snowpack slowly decreases, and winter rains also become more common as temps rise.
It is being driven by Quebec, NE Siberia, Scandinavia, and the Himalayas.

The anomaly in most of these regions is now worsening year over year as they become snowier and snowier, especially Quebec. I suspect the large accumulations of heat in the NW NATL, NW PAC, and the Arctic in general are to blame.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png)
Title: Re: Northern Hemisphere snow cover
Post by: Neven on February 20, 2018, 11:07:49 AM
The Himalayas have been purple ever since I started watching these graphs and put them on the ASIG. I don't know if this skews that snow water equivalent graph. If there is so much extra snowfall there - which doesn't melt out in summer, still purple - we'd hear about it, right?

But anyway, we've been over this before.
Title: Re: Northern Hemisphere snow cover
Post by: crandles on February 20, 2018, 02:45:31 PM
Heavier wet snow which would become more common as temps rise?

Possibly but
1. This happens every year with area near Arctic mainly green with blue in patches.
2. Is it really warm enough for wet snow?

Different hypothesis has been mentioned many time before, warmer air carried more moisture and so more precipitation and it is cold enough to fall as snow or ice pellets.

Occam's razor: if we don't need wet snow to explain it and wet snow seems unlikely then perhaps we should stick to explanation without wet snow.

Just thicker snow as is typical post 1990ish.

Further south we get red areas because it is warmer. Melt / precipitation can fall as rain comes into play further South but not near Arctic.

Is there reason to think we need extra explaining factors?
Title: Re: Northern Hemisphere snow cover
Post by: prairiebotanist on February 20, 2018, 03:02:04 PM
Heavier wet snow which would become more common as temps rise?

...or if other locations are like mine (SE WI, USA), cold rainfall into an existing snowpack can really ramp of SWE even as the depth of that snowpack slowly decreases, and winter rains also become more common as temps rise.
It is being driven by Quebec, NE Siberia, Scandinavia, and the Himalayas.

The anomaly in most of these regions is now worsening year over year as they become snowier and snowier, especially Quebec. I suspect the large accumulations of heat in the NW NATL, NW PAC, and the Arctic in general are to blame.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png)

This graphic shows snow depth anomalies rather than SWE anomalies. SWE can be the same between a 50cm snowpack and a 20cm snowpack.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on February 21, 2018, 08:08:26 PM
Snow Water Equivalent is getting ridiculous, like so much else in the Arctic and beyond this winter
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on February 21, 2018, 08:19:30 PM
Snow Water Equivalent is getting ridiculous, like so much else in the Arctic and beyond this winter

That snow water equivalent. Is that the amount of snow on the arctic ? Because a few days ago there was a post that snow was only until the ankle. Or maybe that was just a local place. I still have to learn the names of many of these places. But your post tells the opposite.
Title: Re: Northern Hemisphere snow cover
Post by: Neven on February 22, 2018, 10:49:30 AM
Snow Water Equivalent is getting ridiculous

Maybe it isn't accurate?
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on February 22, 2018, 11:45:03 AM
Snow Water Equivalent is getting ridiculous

Maybe it isn't accurate?

The graph below shows a similar ridiculousness  -also also from https://www.ccin.ca/ccw/snow/current

This is how they say they do it. Maybe not accurate, but is there anything better around?

Quote
The GCW/FMI SWE Tracker illustrates the current winter records for 2014/2015 (methinks they need to update the blurb) relative to the long-term mean and variability of the snow water equivalent for the Northern Hemisphere (±1 standard deviation calculated for 1982-2012), excluding mountains. The historical SWE record is based on the time series of measurements by two different space-borne passive microwave sensors. The current data combines these satellite measurements with groundbased weather station records in a data assimilation scheme. Updated daily by GlobSnow, a Global Cryosphere Watch initiative, funded by the European Space Agency and coordinated by the Finnish Meteorological Institute
Title: Re: Northern Hemisphere snow cover
Post by: crandles on February 22, 2018, 12:59:48 PM
A couple of comparison images:

(https://static1.squarespace.com/static/56530521e4b0c307d59bbe97/t/5911cba5e6f2e1b0155389d0/1494338481125/?format=750w)

(https://web.archive.org/web/20160701150439im_/http://globalcryospherewatch.org/state_of_cryo/snow/ec-tracker_nh_swe.png)

So well up on 15/16 but not that much different from 16/17
Title: Re: Northern Hemisphere snow cover
Post by: crandles on February 22, 2018, 01:27:51 PM
If there is no change in conditions, then it should be outside 1SD band ~32% of time and outside 2SD band 5% of time.

So options include:

1. 1998-2011 is a short base period, perhaps it didn't capture all the variability.
2. Lots of auto-correlation so when it goes outside bands it tends to stay there a long time. (i.e. Snow begets more snow and no snow on ground allows any snow that falls to melt.)
3. Freak conditions producing large SD deviation for long time.
4. Conditions are changing i.e. changes are suggestive of GW producing more precipitation.
5. Something broken for last 18 ish months producing anomalous values.

Could well be some combination of these (and/or other explanations). Don't think I would want to  claim to be very sure as to which are more likely explanations, but I wouldn't be inclined to rush to judge that it is 4 or 5.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on February 22, 2018, 07:10:11 PM
If there is no change in conditions, then it should be outside 1SD band ~32% of time and outside 2SD band 5% of time.

So options include:

1. 1998-2011 is a short base period, perhaps it didn't capture all the variability.
2. Lots of auto-correlation so when it goes outside bands it tends to stay there a long time. (i.e. Snow begets more snow and no snow on ground allows any snow that falls to melt.)
3. Freak conditions producing large SD deviation for long time.
4. Conditions are changing i.e. changes are suggestive of GW producing more precipitation.
5. Something broken for last 18 ish months producing anomalous values.

Could well be some combination of these (and/or other explanations). Don't think I would want to  claim to be very sure as to which are more likely explanations, but I wouldn't be inclined to rush to judge that it is 4 or 5.

#2 + #4 = Younger Dryas equivalent happening before our eyes, the change since 2015 is on the order of +15-20% SWE at the moment (for same time of yr). That is enormous!

We still have two to four weeks to go before we hit the time of max from last winter as well. Perhaps a 4 handle is obtainable?

The question we have to ask moving forward is how deep it has to get & how cold it has to stay in Quebec & NE Siberia for cover to last all year... and I think we are very close.
Title: Re: Northern Hemisphere snow cover
Post by: RikW on February 23, 2018, 09:10:00 AM
It's just too bad that the only region suffering from more cold/ more winter conditions is the region that is one of the largest polluters and deniers.

Like the earth just wants to make sure we as humanity won't be able to act soon enough.
Title: Re: Northern Hemisphere snow cover
Post by: oren on February 23, 2018, 10:48:33 AM
bbr, this argument seems to be popping up every couple of days, so for the sake of lurkers and newbies I just want to counter that the Younger Dryas is not coming back, there is no continental ice sheet covering the whole of Canada ready to pour its meltwater suddenly into the ocean. And with any precipitation pattern you care to imagine, snow can't last through a summer where temps hit 25C. It's best to continue these arguments in the "negative anomalies of increased snowfall" thread, where it was addressed quite a lot already.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on February 23, 2018, 09:49:24 PM
bbr, this argument seems to be popping up every couple of days, so for the sake of lurkers and newbies I just want to counter that the Younger Dryas is not coming back, there is no continental ice sheet covering the whole of Canada ready to pour its meltwater suddenly into the ocean. And with any precipitation pattern you care to imagine, snow can't last through a summer where temps hit 25C. It's best to continue these arguments in the "negative anomalies of increased snowfall" thread, where it was addressed quite a lot already.
You are wrong. There is a continental ice sheet over Canada at this very moment and it will indeed pour its contents into the ocean over the next few months. Instead of telling me to post in a different thread (i.e. engaging in ad hominem attacks) maybe you could rebut with facts?

https://weather.gc.ca/saisons/animation_e.html?id=month&bc=sea

Looping ^ clearly shows the situation in Canada and if you think the formation of an ice sheet would look at different than our current state of affairs (can't form an ice sheet without deepening snowpack over a huge geographical area... which is what is happening...) I think you are misinformed.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on February 23, 2018, 10:48:30 PM
Guess I am going to have to set someone on ignore.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on February 23, 2018, 10:54:47 PM
I'm with James Lovelock who reckoned that all these positive feedbacks would be overwhelmed by global heating..  Mind you, he did seem to miss the fundamental importance of the oceans.
Title: Re: Northern Hemisphere snow cover
Post by: Neven on February 24, 2018, 01:00:59 AM
Instead of telling me to post in a different thread (i.e. engaging in ad hominem attacks) maybe you could rebut with facts?

Maybe it's me, but I'm not seeing an ad hominem attack in oren's post.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on February 24, 2018, 04:50:22 AM
Instead of telling me to post in a different thread (i.e. engaging in ad hominem attacks) maybe you could rebut with facts?

Maybe it's me, but I'm not seeing an ad hominem attack in oren's post.
(https://media.giphy.com/media/JRF85A7Bcl2YU/giphy.gif)
Title: Re: Northern Hemisphere snow cover
Post by: Neven on February 26, 2018, 08:17:29 PM
I just saw this (http://www.livemint.com/Science/f5K3pah6yCXSkZ7yXHzHMI/Himalayas-getting-warmer-snowfall-decreasing-due-to-global.html) today:

Quote
Himalayas getting warmer, snowfall decreasing due to global warming

The study says total precipitation is increasing while the snowfall is decreasing with concurrent significant increase in rainfall at all zones of Northwestern Himalayas

New Delhi: The Himalayas, the world’s highest mountains, are getting warmer, according to a study published in science journal Current Science.

“Total precipitation (rainfall + snowfall) was found to increase whereas snowfall was found to decrease with concurrent significant increase in rainfall at all zones of NWH,” the study said.

It warned that rising trends in liquid precipitation have a negative influence on Himalayan glaciers and “frequency of hazards such as avalanches and landslides is expected to increase during late winter”.

The study analysed wintertime variability in climatic parameters like temperature (maximum, minimum and mean) and precipitation over Northwestern Himalaya (NWH) along with its constituents — Lower Himalaya (LH), Greater Himalaya (GH) and Karakoram Himalaya (KH) — during three time scales 1991–2015 (25 years), 1991–2000 (10 years) and 2001–2015 (15 years).

It was done by H.S. Negi, Neha Kanda, M.S. Shekhar and A.Ganju of the central government’s Snow and Avalanche Study Establishment, Chandigarh.

It said the “impact of global warming is evident over NWH in form of rising maximum and mean temperature at all zones and NWH”.

“An overall warming signature was observed over NWH since maximum, minimum and mean temperatures followed rising trends with a total increase of 0.9 degrees Celsius, 0.19 degrees Celsius and 0.65 degrees Celsius respectively, in 25 years, the increase being statistically significant for maximum and mean temperatures. However, warming was not consistent over all zones of NWH,” said the study published this week.

“Interestingly, snowfall amount is found to have decreased whereas rainfall amount have increased in 25 years. Furthermore, precipitation at all zones except LH follows decreasing trends in last 15 years (2001–2015) which signals significant climatic change especially after year 2000,” it added.

This is significant as changes in snow and ice cover affect air temperature, sea level and storm patterns.

“The increase in liquid precipitation during winter months over seasonal snow has induced enhanced melting and flood situation in Kashmir recently (5–7 April 2017). Such rising trends in liquid precipitation over snowfall, have a negative influence on the Himalayan glaciers. In addition, the frequency of hazards like avalanches and landslides is expected to increase during late winter,” it warned.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on February 27, 2018, 08:17:18 PM
I attach the two latest graphs from https://www.ccin.ca/ccw/snow/current

They both show Snow Water Mass (Equivalent) still going up like a train. But the first says  about 3,900 GT (Km3) and the second about 3,300 GT. The second excludes mountains - does the first? Or is it different methodology?

methodology for first image:-
Quote
Figure 3: These plots present time series (updated daily) of the current amount of water stored by the seasonal snowpack (cubic km) over (a) Northern Hemisphere land areas (excluding Greenland), (b) North America, and (c) Eurasia. Snow depth from the CMC analysis is converted to snow water equivalent using a density climatology obtained from snow survey data. The time series average and range between ±1 standard deviation (calculated for 1998/99 to 2011/12) shows how current conditions compare to historical variability.

Methodology for second image:-
Quote
Figure 6: The GCW/FMI SWE Tracker illustrates the current winter records for 2014/2015, relative to the long-term mean and variability of the snow water equivalent for the Northern Hemisphere (±1 standard deviation calculated for 1982-2012), excluding mountains. The historical SWE record is based on the time series of measurements by two different space-borne passive microwave sensors. The current data combines these satellite measurements with groundbased weather station records in a data assimilation scheme. Updated daily by GlobSnow, a Global Cryosphere Watch initiative, funded by the European Space Agency and coordinated by the Finnish Meteorological Institute
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on February 27, 2018, 08:32:28 PM
I attach the two latest graphs from https://www.ccin.ca/ccw/snow/current

They both show Snow Water Mass (Equivalent) still going up like a train. But the first says  about 3,900 GT (Km3) and the second about 3,300 GT. The second excludes mountains - does the first? Or is it different methodology?

methodology for first image:-
Quote
Figure 3: These plots present time series (updated daily) of the current amount of water stored by the seasonal snowpack (cubic km) over (a) Northern Hemisphere land areas (excluding Greenland), (b) North America, and (c) Eurasia. Snow depth from the CMC analysis is converted to snow water equivalent using a density climatology obtained from snow survey data. The time series average and range between ±1 standard deviation (calculated for 1998/99 to 2011/12) shows how current conditions compare to historical variability.

Methodology for second image:-
Quote
Figure 6: The GCW/FMI SWE Tracker illustrates the current winter records for 2014/2015, relative to the long-term mean and variability of the snow water equivalent for the Northern Hemisphere (±1 standard deviation calculated for 1982-2012), excluding mountains. The historical SWE record is based on the time series of measurements by two different space-borne passive microwave sensors. The current data combines these satellite measurements with groundbased weather station records in a data assimilation scheme. Updated daily by GlobSnow, a Global Cryosphere Watch initiative, funded by the European Space Agency and coordinated by the Finnish Meteorological Institute
I believe the first is mountain-inclusive; the Canadians are much more progressive than the Finns in this regard.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on March 05, 2018, 08:52:00 PM
Signs of maximum soon ?
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 06, 2018, 12:20:47 AM
Signs of maximum soon ?
I wonder. It seems like North America should continue a sharp increase over the next week. Eurasia should also see substantial snowfall.

The gains over North America will largely be over the mid-latitudes. There seems to be a worsening battle between the expanding annual ice sheet & the warmest-ever SSTs over the NW NATL. It seems as though the Gulf Stream has drifted very far north and has now subsumed the Gulf of Maine entirely.

This seems to have caused a rather abrupt instance of sea level rise across the NE seaboard. Montauk has been +2 to +3 feet above normal for days!

https://tidesandcurrents.noaa.gov/waterlevels.html?id=8510560&bdate=20180304&edate=20180305&units=standard&timezone=GMT&interval=6

The warmth extends the length of the seaboard, as do the high readings relative to normal.

https://tidesandcurrents.noaa.gov/waterlevels.html?id=8723214&bdate=20180304&edate=20180305&units=standard&timezone=GMT&interval=6

Judging by the linked maps, it seems this is to be blamed on a very dramatic warming and northern push by the Gulf Stream? It looks like a wall of oceanic heat is backing up into the NE US/NW NATL and shows no signs of slowing down. Probably partly to blame on the record +500MB February heights over the region.

https://weather.gc.ca/saisons/animation_e.html?id=month&bc=sea

We should see another major winter storm on Wednesday, and another possibility by D5-6 means that the NE/Quebec should only be adding to current anomalous mass over the foreseeable future.

I think we could max at over 4,500KM^3 across the entire NHEM, and North America could crack 1,500KM^3 on its own.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 06, 2018, 06:08:05 AM
Something I have also thought about and that some might consider a variable worth studying is Hawaiian snowfall impact on hemispheric patterns.

Mauna Loa and Mauna Kea have fairly limited areas but the wintertime contrast between sun angle there with Alaska is simply enormous, in fact, they receive about 30X as much solar radiation.

It is feasible to consider that dumping of cold out of Bering and into the NW Pacific/Rockies could indirectly ultimately impact Hawaii, increasing snowfall (potentially). Though limited in relative scope, even with a reduced snow line, in December, 200KM^2 of cover on Mauna Kea and Mauna Loa has the equivalent effect of 6000KM^2 of cover over Alaska!

We currently have about 150KM^2 FWIW.

In any case, this must have some substantial impact on weather, as well as the subsequent snowmelt. Hawaiian snow droughts + snowstorms could have increasing importance as weather weirding results in increasingly anomalous airmasses reaching the islands and while they don't look like much, in a season like winter, their impact is very outsized.

https://worldview.earthdata.nasa.gov/?p=geographic&l=MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2017-03-02&z=3&v=-156.37888433024645,19.251366073726487,-154.97812749430895,19.943504745601487

In any case, forecast calls for more snow!
Title: Re: Northern Hemisphere snow cover
Post by: RikW on March 06, 2018, 04:30:45 PM
isn't that high tide just caused by the winds? Last week i read in the Dutch news that they closed some of the storm-gates to prevent too much water getting blown away. Water lvl's were lowest in 30 years for the Rotterdam-area.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on March 06, 2018, 04:47:48 PM
Rutgers Univ. NH Snow Cover extent figure for Feb 2018 is 46.29 million sqr km.

That is 0.7 million above the 1981-2010 average.

It's a little up on the previous two years.
Title: Re: Northern Hemisphere snow cover
Post by: johnm33 on March 06, 2018, 07:12:27 PM
isn't that high tide just caused by the winds?
and that huge low pressure system
Title: Re: Northern Hemisphere snow cover
Post by: oren on March 08, 2018, 02:25:07 PM
Regarding the NH snow water equivalent chart from Environment Canada, does anyone know if it's possible to view some kind of map of the anomaly? Meaning - where is all that snow to be found? The NH is a big place.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on March 08, 2018, 02:56:44 PM
Regarding the NH snow water equivalent chart from Environment Canada, does anyone know if it's possible to view some kind of map of the anomaly? Meaning - where is all that snow to be found? The NH is a big place.

Environment Canada ( https://www.ccin.ca/ccw/snow/current ) has a snow depth departures map. But i expect you have looked at that already. Gives one a clue.
Title: Re: Northern Hemisphere snow cover
Post by: oren on March 08, 2018, 03:20:06 PM
Regarding the NH snow water equivalent chart from Environment Canada, does anyone know if it's possible to view some kind of map of the anomaly? Meaning - where is all that snow to be found? The NH is a big place.
Environment Canada ( https://www.ccin.ca/ccw/snow/current ) has a snow depth departures map. But i expect you have looked at that already. Gives one a clue.
Thanks, I somehow missed that. Will bookmark. I want to do some little pet project.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on March 08, 2018, 04:15:08 PM
Regarding the NH snow water equivalent chart from Environment Canada, does anyone know if it's possible to view some kind of map of the anomaly? Meaning - where is all that snow to be found? The NH is a big place.
Environment Canada ( https://www.ccin.ca/ccw/snow/current ) has a snow depth departures map. But i expect you have looked at that already. Gives one a clue.
Thanks, I somehow missed that. Will bookmark. I want to do some little pet project.

When you publish I expect an acknowledgement for my untiring assistance blah blah blah
Title: Re: Northern Hemisphere snow cover
Post by: Archimid on March 09, 2018, 04:08:35 AM
Quote
Regarding the NH snow water equivalent chart from Environment Canada, does anyone know if it's possible to view some kind of map of the anomaly? Meaning - where is all that snow to be found? The NH is a big place.

Also, Climate Reanalyzer sea ice/snow cover tab. It doesn't have depth information but the periphery is easier to inspect in their projection.
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on March 09, 2018, 05:06:53 AM
Does anyone know where we can find a table of daily Northern Hemisphere snow cover ?

The best I could find is Rutgers, but even though they publish daily maps, their table is updated only  once per month.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 09, 2018, 06:20:32 AM
I think the Climate Reanalyzer data is very wrong as the GFS has a very poor snow initialization scheme (which it is based on). At least it is far inferior to the Canadian's (IMO), which makes sense given how much more important snowcover is perceived to Canadian vs. US weather (though reality is... it is equally important for both!!!).

The Canadian map animated (at link) gives the best visualization of the yearly annual snowpack's growth.

https://weather.gc.ca/saisons/animation_e.html?id=month&bc=sea

This year, we have broken the old graph's limits, and are now cranking past 1,500KM^3 of SWE across North America. The lion's share of the anomaly is over Quebec, though splotches of high cover are present over almost all of the continent over 45N.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

I suspect that the melting of this enormous mass of snow and ice will be quite a taxing event on the already out of whack circulation in the North Atlantic. With so much heat in the NW NATL, summertime impacts on Greenland are also (IMO) likely, which means we may be dealing with an anomalously large melt across several regions adding a much more substantive injection of freshwater than any previous year.

We shall see...!
Title: Re: Northern Hemisphere snow cover
Post by: oren on March 09, 2018, 07:03:37 AM
Quote
Regarding the NH snow water equivalent chart from Environment Canada, does anyone know if it's possible to view some kind of map of the anomaly? Meaning - where is all that snow to be found? The NH is a big place.
Also, Climate Reanalyzer sea ice/snow cover tab. It doesn't have depth information but the periphery is easier to inspect in their projection.
Thanks Archimid, I'm actually interested at the moment in snow depth rather than snow cover.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 11, 2018, 05:52:57 AM
North American snow-water-equivalent must be at a record, at a current figure of about 1,550KM^3.

Over the next week+, this should rise substantially further, as additional major falls should continue over the Rockies, and as SE Quebec is buried further. There will be significant snowfall further south as well and while this will be transient, if sustained for a week or three, perhaps we see a maximum over 1,700KM^3?

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

(https://www.tropicaltidbits.com/analysis/models/gem/2018031100/gem_asnow_namer_40.png)
Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on March 11, 2018, 07:40:10 AM
Just looking at New Mexico, Intellicast (http://www.intellicast.com/Travel/Weather/Snow/Cover.aspx) offers a different picture of coverage.  (You may have to click on the picture to see NM.)
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on March 11, 2018, 09:01:35 PM
Does anyone know where we can find a table of daily Northern Hemisphere snow cover ?

The best I could find is Rutgers, but even though they publish daily maps, their table is updated only  once per month.

Rutgers do a weekly table also :

https://climate.rutgers.edu/snowcover/table_area.php?ui_set=0&ui_sort=0
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on March 12, 2018, 03:11:17 AM
Is that map saying snow depth of 2-4 inches in Chicago on 3/10? We haven't had any real snow on the ground here for 2 weeks.
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on March 12, 2018, 05:39:15 AM
Does anyone know where we can find a table of daily Northern Hemisphere snow cover ?

The best I could find is Rutgers, but even though they publish daily maps, their table is updated only  once per month.

Rutgers do a weekly table also :

https://climate.rutgers.edu/snowcover/table_area.php?ui_set=0&ui_sort=0

Thanks Niall. That is useful.
I could have sworn that last year they were updating that weekly table also only once a month.
But this year they already posted week 9, which suggests a weekly update.
Let's keep an eye on that table and see if next week they post week 10.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 13, 2018, 08:20:27 AM
The 00z EURO forecasts an epic cold and snow outbreak over Eastern North America & most all of Europe, sustained straight through D10. Weather.us gives great maps, rolling the snow depth forward across North America, one can't help get the impression the annual Canadian ice sheet is extending its toes towards the Atlantic, and the NE US is in the way. The totals just keep mounting....

We will lose the battle to the sun within another few weeks, but this March may be rather extraordinary for both its continental cold and snow.

In fact, if the 00z EURO is right, there will be *sustained* gains across most all regions, with losses confined to vicinity of Kazakhstan -- even immediately to the north of there, Russia's snowpack will be gaining substantial bulk.

Title: Re: Northern Hemisphere snow cover
Post by: Iceismylife on March 13, 2018, 11:08:37 PM
...

The question we have to ask moving forward is how deep it has to get & how cold it has to stay in Quebec & NE Siberia for cover to last all year... and I think we are very close.
Just how deep does it have to get.  The surface will be at zero C.  If you don't get 100% melt out each year you get a new ice sheet.
Title: Re: Northern Hemisphere snow cover
Post by: oren on March 17, 2018, 11:31:36 PM
So I have been wondering for a while about two related questions: all that snow that is said to be in Quebec - is it really there? And if it's there - will it last longer on the ground when spring arrives? (And is an ice age coming along??)
The reason for the first question is that it is difficult (at least for me) to get the data behind the maps and snow water equivalent charts, and that in trying to get specific weather station data to substantiate the SWE chart and the snow depth and anomaly map, I had some challenges.
The reason for the second question is the lively discussion on the forum of what the SWE anomaly actually means.
I finally managed to generate a snow depth database for the past 19 seasons (2000-2018) for a single station that lies inside the anomalous area in Quebec - Goose bay (yes, in Labrador actually). I used Ogimet Synop data - the only side where I could get historical snow depth measurements.
https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71816&ano=2018&mes=3&day=20&hora=18&min=0&ndays=50 (https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71816&ano=2018&mes=3&day=20&hora=18&min=0&ndays=50)
I didn't use this link but actually used multiple queries to get the raw synop reports, parsed them, and then trimmed then to cut off late snow days after the winter pack has melted out, and days that only had snow patches remaining. Had to use some judgement and spent ages getting it sorted out.
Note: Goose Bay is the only station in the Ogimet database that is inside the high snow area in Quebec and has snow depth data. Two other Quebec stations - Kuujjuaq and La Grande Riviere have snow depth but fall outside the anomalous area.

My results are contained in two hard-to-read charts, showing all these seasons together. I think these charts answer the questions qualitatively:
A. Yes, the snow is really there, much thicker than usual.
B. Melt out of winter snow pack occurs in late April or early May. Lots of accumulated snow in February-March does have a tendency to melt out a bit later, perhaps by a week (two at the very most). Note: it seems light April snows are much better at delaying melt-out than heavy March snows.

Bottom line: we are not remotely close to the snow lasting through the summer, and I doubt that we ever will be. An ice age doesn't seem to be approaching.
On the other hand, adding one week of snow cover during peak insolation season does count for some albedo effect. I don't think it's significant enough to affect the melting season, especially as the nearby Baffin bay is a peripheral area, downstream of the main arctic basin in terms of currents.
I suspect that in Siberia things might be a bit different as the ESS is much more important than Baffin, but I'm not sure if I can bring myself to build the same database for some station(s) along that shore.
If anyone is aware of a website that offers direct downloads of historical snow depth data for specific meteorological stations, please post links.

Charts are snow depth in cm, for Goose Bay (station 71816), vs. day of year (negative days are of the previous calendar year).
Title: Re: Northern Hemisphere snow cover
Post by: Neven on March 17, 2018, 11:39:54 PM
Nice work, oren.

The reason for the first question is that it is difficult (at least for me) to get the data behind the maps and snow water equivalent charts, and that in trying to get specific weather station data to substantiate the SWE chart and the snow depth and anomaly map, I had some challenges.

For what it's worth, I've sent two e-mails to CCIN, one to the mail address on the Contact us (https://www.ccin.ca/about/contact) page, and one directly to Dr Julie Friddell. No answer as of yet.

My question:

Quote
I regularly have a look at some of your graphs (also displayed on this website) and noticed how this year's trend lines on the Snow water equivalent graphs are extremely high for the time of year. I wanted to make sure the data behind the graphs is processed correctly before using the graphs in any of my writing. Do you know if this is so, or if not, give me the mail address of the person who does?
Title: Re: Northern Hemisphere snow cover
Post by: TerryM on March 18, 2018, 12:37:59 AM
oren
I was in La Grand Riviere in the first week(s) of May in 2006 or 2007. No snow even in permanently shaded nooks, probably because it was T-shirt weather.


Same conditions at Goose Bay in May of 2005.


If I get up in those regions again I'll try to pay more attention.
Terry
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 19, 2018, 05:16:59 AM
Secondary max impending in a few weeks?

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/nh_swe.png)

Eurasia SWE rising while North America has stabilized... North America should increase quite a bit this week.
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on March 21, 2018, 10:26:35 AM
Does anyone know where we can find a table of daily Northern Hemisphere snow cover ?

The best I could find is Rutgers, but even though they publish daily maps, their table is updated only  once per month.

Rutgers do a weekly table also :

https://climate.rutgers.edu/snowcover/table_area.php?ui_set=0&ui_sort=0

Thanks Niall. That is useful.
I could have sworn that last year they were updating that weekly table also only once a month.
But this year they already posted week 9, which suggests a weekly update.
Let's keep an eye on that table and see if next week they post week 10.

It's now March 21, week 11 AFAIK.
Rutgers still posts only week 9 as the latest.
So I think they really update this chart of NH snow cover only once per month.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on March 21, 2018, 11:16:35 AM
The question we have to ask moving forward is how deep it has to get & how cold it has to stay in Quebec & NE Siberia for cover to last all year... and I think we are very close.
Just how deep does it have to get.  The surface will be at zero C.  If you don't get 100% melt out each year you get a new ice sheet.

I show below two images dated 20th March from Environment Canada at https://www.ccin.ca/ccw/snow/current

The first shows snow depth departures from average in the Northern Hemisphere. You will observe that for most of the Canadian Barrens and the Russian Tundra the snow is around 10 to 20 cms deeper than usual. It will melt a bit later but it will melt out by early summer.

The second (very hard to read) is an extract of the map showing snow depth in the Eastern N. America including Quebec Province. You will see that apart from the coastal fringes most snow depth is bound by the 25, 50 and 75 cm snow depth contours.

Surly it won't last the summer.  I do not believe a few hundred gigatons of additional snow spread over a good many million km2 of Northern Canada and Russia is a preview of the next ice age.

However, what I am convinced it will mean is flows of the great Northern Rivers that flow north into the Arctic Ocean will greatly increase, dumping loads of carbon rich soils into shallow seas, and through providing additional and longer  insulation during the winter accelerate degradation of land-based permafrost. There is evidence of this (have a root around in the permafrost thread).
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on March 21, 2018, 10:31:52 PM

It's now March 21, week 11 AFAIK.
Rutgers still posts only week 9 as the latest.
So I think they really update this chart of NH snow cover only once per month.

That's a pity. A month is a long time in the Arctic !
Title: Re: Northern Hemisphere snow cover
Post by: Iceismylife on March 22, 2018, 02:17:06 AM
...

The question we have to ask moving forward is how deep it has to get & how cold it has to stay in Quebec & NE Siberia for cover to last all year... and I think we are very close.
Just how deep does it have to get.  The surface will be at zero C.  If you don't get 100% melt out each year you get a new ice sheet.
The lower reaches of Greenland melt 5 feet of ice a year. At 12 inches of snow for an inch of water. That works out to 60 feet of snowfall.  Less than that will melt out more than that will not.

So will we get 60 feet of snowfall with open water in the Arctic basin each year?
Title: Re: Northern Hemisphere snow cover
Post by: Archimid on March 22, 2018, 03:00:49 AM
Quote
So will we get 60 feet of snowfall with open water in the Arctic basin each year?

After the first ice free arctic, the winter will be horrible. The atmosphere will be soup relative to the historical levels of the holocene, but the arctic night is a formidable negative forcing. I don't see how temperatures won't drop below freezing, specially after the oceans released all the albedo heat. It might not get cold enough to get much sea ice, but it's going to snow like it never has during the holocene.  I don't know if 60 deep over the whole hemisphere for many months, but it's going to be huge.

But after a few iterations of ice free arctics, snow should be a rare thing.
Title: Re: Northern Hemisphere snow cover
Post by: Iceismylife on March 22, 2018, 03:13:08 AM
Quote
So will we get 60 feet of snowfall with open water in the Arctic basin each year?

After the first ice free arctic, the winter will be horrible. The atmosphere will be soup relative to the historical levels of the holocene, but the arctic night is a formidable negative forcing. I don't see how temperatures won't drop below freezing, specially after the oceans released all the albedo heat. It might not get cold enough to get much sea ice, but it's going to snow like it never has during the holocene.  I don't know if 60 deep over the whole hemisphere for many months, but it's going to be huge.

But after a few iterations of ice free arctics, snow should be a rare thing.
What I see happening is this.  Ice free.  big wind.  lots of waves.  All the fresh water run off mixed in with salt water to the point that it sinks to the abysmal depths.

This pulls the gulfstream through the CAA and around the west side of Greenland.  Is 60 feet of lake effect snow doable?

Edit: Minus 10c not freezing. Open water gets + 20C warmer forcing.  Right on the edge of freezing over.
Title: Re: Northern Hemisphere snow cover
Post by: johnm33 on March 22, 2018, 10:57:39 AM
"What I see happening is this."
The Atlantic waters have their own inherent inertia, it'll carry them east once they get far north enough, as now. They may split some % going due east to 'green up' Spain and North Africa, the rest accelerated north by the prodigious evaporation taking place in the arctic, driving an enhanced saline current out at depth. That in turn will develop its own inertia. 60ft of snow? possible where/when the north winds are persitent and forced to climb, my guess around Alberta/Montana, Lake Balkash and to a lesser extent Quebec  and south to the great lakes.
  There'll also be an enhanced flow through the CAA of fresher surface waters escaping the arctic instead of being held by the coarse inverted topography beneath the ice. I suspect we'll see  rapid erosion taking place similar to that which has begun in Svalbard, reshaping the islands when it begins to rain there on a persistent basis.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 22, 2018, 09:20:44 PM
So I have been wondering for a while about two related questions: all that snow that is said to be in Quebec - is it really there? And if it's there - will it last longer on the ground when spring arrives? (And is an ice age coming along??)
The reason for the first question is that it is difficult (at least for me) to get the data behind the maps and snow water equivalent charts, and that in trying to get specific weather station data to substantiate the SWE chart and the snow depth and anomaly map, I had some challenges.
The reason for the second question is the lively discussion on the forum of what the SWE anomaly actually means.
I finally managed to generate a snow depth database for the past 19 seasons (2000-2018) for a single station that lies inside the anomalous area in Quebec - Goose bay (yes, in Labrador actually). I used Ogimet Synop data - the only side where I could get historical snow depth measurements.
https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71816&ano=2018&mes=3&day=20&hora=18&min=0&ndays=50 (https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71816&ano=2018&mes=3&day=20&hora=18&min=0&ndays=50)
I didn't use this link but actually used multiple queries to get the raw synop reports, parsed them, and then trimmed then to cut off late snow days after the winter pack has melted out, and days that only had snow patches remaining. Had to use some judgement and spent ages getting it sorted out.
Note: Goose Bay is the only station in the Ogimet database that is inside the high snow area in Quebec and has snow depth data. Two other Quebec stations - Kuujjuaq and La Grande Riviere have snow depth but fall outside the anomalous area.

My results are contained in two hard-to-read charts, showing all these seasons together. I think these charts answer the questions qualitatively:
A. Yes, the snow is really there, much thicker than usual.
B. Melt out of winter snow pack occurs in late April or early May. Lots of accumulated snow in February-March does have a tendency to melt out a bit later, perhaps by a week (two at the very most). Note: it seems light April snows are much better at delaying melt-out than heavy March snows.

Bottom line: we are not remotely close to the snow lasting through the summer, and I doubt that we ever will be. An ice age doesn't seem to be approaching.
On the other hand, adding one week of snow cover during peak insolation season does count for some albedo effect. I don't think it's significant enough to affect the melting season, especially as the nearby Baffin bay is a peripheral area, downstream of the main arctic basin in terms of currents.
I suspect that in Siberia things might be a bit different as the ESS is much more important than Baffin, but I'm not sure if I can bring myself to build the same database for some station(s) along that shore.
If anyone is aware of a website that offers direct downloads of historical snow depth data for specific meteorological stations, please post links.

Charts are snow depth in cm, for Goose Bay (station 71816), vs. day of year (negative days are of the previous calendar year).

Hi Oren,

This is excellent work!

I am curious to see how this year unfolds relative to others in late spring. I think if we fail to see appreciable delay in melt, it shows that we need to go well beyond current warming to precipitate enough snowfall that ^ does occur.

Very interesting to see results as we push deeper into what has traditionally been the warm season...!

Would also like to see Newfoundland or others if you can dig up?

It seems at least for the moment, the gap vs normal continues to widen in the areas already mentioned.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png)
Title: Re: Northern Hemisphere snow cover
Post by: oren on March 23, 2018, 04:58:32 AM
Terribly sorry to disappoint. Here is a location in the bluish area in east Siberia. Sredne-Kolymsk (Russia), station 25206, Lat 67, Lon 153. It shows the same behavior, much higher snow resulting in no delay in melt-out date. This theory of a new ice age doesn't hold water (pun intended).
I'll grant you this caveat: at least at these levels of snowfall. If/when we get to 10x historical levels, we should check again.
But if possible until then, let's cool down (pun intended) the tall words regarding the effect of higher land snow on arctic sea ice, the weather in general, and impending glaciation. It's just not happening. More snow, same spring date, not very interesting.
I'll grant you this as well: pick another synop station with snow depth data going back 10-20 years, from this map here, and I'll try to generate a similar chart for that station.
https://www.ogimet.com/gsynop_nav.phtml.en (https://www.ogimet.com/gsynop_nav.phtml.en)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 23, 2018, 02:53:51 PM
Terribly sorry to disappoint. Here is a location in the bluish area in east Siberia. Sredne-Kolymsk (Russia), station 25206, Lat 67, Lon 153. It shows the same behavior, much higher snow resulting in no delay in melt-out date. This theory of a new ice age doesn't hold water (pun intended).
I'll grant you this caveat: at least at these levels of snowfall. If/when we get to 10x historical levels, we should check again.
But if possible until then, let's cool down (pun intended) the tall words regarding the effect of higher land snow on arctic sea ice, the weather in general, and impending glaciation. It's just not happening. More snow, same spring date, not very interesting.
I'll grant you this as well: pick another synop station with snow depth data going back 10-20 years, from this map here, and I'll try to generate a similar chart for that station.
https://www.ogimet.com/gsynop_nav.phtml.en (https://www.ogimet.com/gsynop_nav.phtml.en)
TY Oren!

How about this one?

https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71818&ano=2018&mes=3&day=23&hora=12&min=0&ndays=30

And I am not sure if you are correct re: 10X higher (though it is certainly higher). I think if we get to the point where large amounts of snow remain annually, the amount required to endure heat waves through summertime will slowly drop as the general increase becomes more obvious across the hemisphere and WACCY weather becomes even more persistent, if that makes sense? It will still be enormous, but a stagnation in summertime weather patterns is the best thing that could happen for certain regions when it comes to preserving snowcover (proximity to Greenland is... most key!)

Also this one!

https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71728&ano=2018&mes=3&day=23&hora=12&min=0&ndays=30

and finally for now,

https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71834&ano=2018&mes=3&day=23&hora=12&min=0&ndays=30
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on March 24, 2018, 04:37:13 AM
oren, first of all, compliments for your fine work on snow thickness in the Arctic.

Quote
It shows the same behavior, much higher snow resulting in no delay in melt-out date. This theory of a new ice age doesn't hold water (pun intended).

This does make perfect physical sense : water content of snow is typically something like 1/3rd or so. So even with a meter of snow, it translates only to 30 cm of ice. That will melt out quite rapidly, compared to Arctic sea ice which is about 1.5 m even for FYI.

Add to that the fact that snow in the Northern Hemisphere falls on trees and other 'irregular' surfaces, which causes rapid melt once it gets started, and it makes perfect sense that snow depth is not a good predictor for timing of melt-out.

Temperature is though.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on March 24, 2018, 09:52:53 PM

Add to that the fact that snow in the Northern Hemisphere falls on trees and other 'irregular' surfaces

The 3.3 million km2 of the Canadian Barrens is treeless and at a maximum elevation of 300 metres. The Russian Tundra of even more km2 is also treeless and mostly flat as a pancake. Although I also have no belief in a looming ice age,  it would be nice to have useable data for these very high latitudes.
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on March 25, 2018, 06:10:04 AM

Add to that the fact that snow in the Northern Hemisphere falls on trees and other 'irregular' surfaces

The 3.3 million km2 of the Canadian Barrens is treeless and at a maximum elevation of 300 metres. The Russian Tundra of even more km2 is also treeless and mostly flat as a pancake. Although I also have no belief in a looming ice age,  it would be nice to have useable data for these very high latitudes.

You are right that the highest latitude lands are treeless and thus it's harder for snow there to melt out. But overall Northern Hemisphere snow cover is now 45 million km2, so these barren lands are just a small fraction of snow covered land.

But surface properties is just a side-show. The point I was trying to make is that for snow melt, temperature is much more important than snow depth. Once air temps are above 0 C, snow melts rapidly.
Title: Re: Northern Hemisphere snow cover
Post by: oren on March 25, 2018, 11:35:30 AM
TY Oren!

How about this one?

https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71818&ano=2018&mes=3&day=23&hora=12&min=0&ndays=30

And I am not sure if you are correct re: 10X higher (though it is certainly higher). I think if we get to the point where large amounts of snow remain annually, the amount required to endure heat waves through summertime will slowly drop as the general increase becomes more obvious across the hemisphere and WACCY weather becomes even more persistent, if that makes sense? It will still be enormous, but a stagnation in summertime weather patterns is the best thing that could happen for certain regions when it comes to preserving snowcover (proximity to Greenland is... most key!)
It takes ages to process but I finally completed one of these. I think it should lay your argument to rest. Seriously. Take a look at 2003, where 2 meters of snow seem to have disappeared in two days, Apr 25th-27th. Compare to 2002 where half the snow lasted 2 more weeks.
I'm linking to the 2003 data so you can see the weather around that time. Temps rose to 11 degC max the day before. And that was before a lot of global warming in the past 15 years.
https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71818&ano=2003&mes=5&day=23&ndays=50 (https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71818&ano=2003&mes=5&day=23&ndays=50)
Bottom line: thick snow does not create its own climate (at least in Canada), and does not last longer on the ground when the warm spring comes.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 25, 2018, 10:03:20 PM
TY Oren!

How about this one?

https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71818&ano=2018&mes=3&day=23&hora=12&min=0&ndays=30

And I am not sure if you are correct re: 10X higher (though it is certainly higher). I think if we get to the point where large amounts of snow remain annually, the amount required to endure heat waves through summertime will slowly drop as the general increase becomes more obvious across the hemisphere and WACCY weather becomes even more persistent, if that makes sense? It will still be enormous, but a stagnation in summertime weather patterns is the best thing that could happen for certain regions when it comes to preserving snowcover (proximity to Greenland is... most key!)
It takes ages to process but I finally completed one of these. I think it should lay your argument to rest. Seriously. Take a look at 2003, where 2 meters of snow seem to have disappeared in two days, Apr 25th-27th. Compare to 2002 where half the snow lasted 2 more weeks.
I'm linking to the 2003 data so you can see the weather around that time. Temps rose to 11 degC max the day before. And that was before a lot of global warming in the past 15 years.
https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71818&ano=2003&mes=5&day=23&ndays=50 (https://www.ogimet.com/cgi-bin/gsynres?lang=en&ind=71818&ano=2003&mes=5&day=23&ndays=50)
Bottom line: thick snow does not create its own climate (at least in Canada), and does not last longer on the ground when the warm spring comes.
I still think we are heading for a background state where 2003 will soon be irrelevant. But I do think your evidence is compelling in showing that high totals are still vulnerable to melt.

We are again at a new hemispheric SWE maximum btw:

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/nh_swe.png)

Led by another uptick in North America while Eurasia has stalled. North American maxes seem to follow Eurasia's so it may be that we see a continued uptick in NAmerican SWE through early April while Eurasia plateaus/peaks by 4/1?

While we are finally entering the time of year where melt can begin to occur over regions like Quebec, it is also when they open up to moisture. The lead pack generation this year is a substantial buffer in this regard in that large parts of the region can sustain 24 hours+ of 50F+ temperatures while retaining snowpack and then rebuilding on the back-end. I expect volatility will increase substantially over the next few weeks but volume may prove surprisingly resilient.

(https://www.tropicaltidbits.com/analysis/models/gem/2018032512/gem_asnow_namer_40.png)

(https://www.tropicaltidbits.com/analysis/models/gfs/2018032512/gfs_asnow_namer_41.png)

(https://www.tropicaltidbits.com/analysis/models/gem/2018032512/gem_T2ma_namer_41.png)

I don't think we've ever seen a potential setup more conducive to maintaining Canadian volume in April than this ever, actually:

(https://www.tropicaltidbits.com/analysis/models/gem/2018032512/gem_z500aNorm_namer_41.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018032512/ecmwf_z500aNorm_namer_11.png)

Could the modeling change? Yes.

But if this is correct, will it worsen as we head into May and the Bering's situation goes from catastrophic to ice-free entirely, with Chuchki and Beaufort in hot pursuit? I think that is quite possible. And if the ridiculously resilient pattern can manage to maintain/worsen as the hemispheric heat engine kicks into high gear as the summer equinox approaches, we may see crazier weather than ever before.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on March 26, 2018, 01:32:23 AM
Thanks for those graphs Oren and I appreciate your diligence.

However I do wonder about the snow depth figures. I have often seen spurious snow depth figures appear on Ogimet from time to time. It automatically takes them from the synop codes but what if the synops had gone awry ? It does happen.

I have zoomed in on the few hours (image attached) when the big drop occurred and very much wonder if a full 2 metre of snow could disappear in 6 hours  :o

On the morning of 24/04 at 12 UTC there was 288 cm. They day had some rain and some sun and maxed at 11.2 C and depths decreased by 15cm leaving a depth of 273 cm on the morning of 25/04 at 12 UTC. That seems pretty understandable (ie a 15cm drop).

Then the big jump occurs. It goes from 273cm at 12 UTC  to just 75cm at 18 UTC. There was sunshine during the day but the max of 10.8 C was slightly down on the previous day. Yet there was a drop of almost 200cm. That's about the height of a standard door !

That's very odd. 
 

Title: Re: Northern Hemisphere snow cover
Post by: oren on March 26, 2018, 03:50:24 AM
Niall, I was wondering about that myself. I contented myself with checking the data in terms of consistency - it's high in all preceding days, and low in all following days. The physics don't make much sense, but I'm pretty sure there was a lot of snow one week, and gone the next, though I doubt if one day describes it properly. Perhaps there was some drifting or uneven melting. As the goal of my "research" was to correlate max snow thickness with snow melt-out dates (really in order to debunk a certain theory...), the specific dynamics didn't matter that much, it was more of an anecdote serving to highlight the result.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on March 26, 2018, 06:20:11 PM
It does get difficult trying to link snow depths with Arctic Sea Ice. The way I look at it, it is as a buffer zone, tempering the heat advecting northwards. The high albedo associated with snow ensures surface temperatures remain colder for longer and nights can still be very cold as spring advances.

Last year, I see a good example over the far north of Eurasia. Persistent snow cover and a synoptic weather pattern that helped maintain the snow cover, produced a very cold May/Jun period over the far north of Europe. (Copernicus EU monthly surface anomalies attached).

The snow line remained considerably further south than in 2016. The GIF attached contrasts the snow cover for the two years 2016 and 2017 for May 16th.

What effect did this cold anomaly have on ice cover in the seas further north (namely Barents & Kara) ? For atmospheric melt the effect will be considerable because there will be a large temperature difference between air advecting north over a snowy surface then over one without snow.

Of course atmospheric melt is only half the picture as melt will still be on going from the ocean underneath and the cooler northern atmosphere would only have a small effect  on cooling the ocean SSTs.

So here is what NSDIC reported in their monthly report for June 2017.  "Sea ice was especially slow to retreat in the Atlantic sector of the Arctic .....The ice edge expanded in the Barents and Greenland Seas until the end of May, when the ice finally started to retreat ".

In July 2017 "Through the first week of July, extent closely tracked 2012 levels. The rate of decline then slowed, so that as of July 17, extent was 169,000 square kilometers  above 2012 for the same date . The spatial pattern of ice extent differs from 2012, with less ice in the Chukchi and East Siberian Seas in 2017, but more in the Beaufort, Kara, and Barents Seas and in Baffin Bay ."

Given the very low state of ice following winter 16/17, I wonder how much effect the north Eurasian cold & snow cover had in preventing a quick melt out of the Barents and Kara last May/June.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on March 26, 2018, 10:14:23 PM
Lake Superior is going to be re-icing with vigor by D4-5 and by D10 the models are showing coverage rising rapidly. That would be April 5th...

Title: Re: Northern Hemisphere snow cover
Post by: icefisher on April 01, 2018, 01:46:26 AM
The central northern USA is getting another shot of cold from the polar vortex anchored over Hudson Bay.  Tomorrow with 6-8cm. of snow expected over central Missouri-Illinois it will be the first Easter snow since 1917.  The usual "Where's the warming" is likely to be heard.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 01, 2018, 06:33:40 PM
The central northern USA is getting another shot of cold from the polar vortex anchored over Hudson Bay.  Tomorrow with 6-8cm. of snow expected over central Missouri-Illinois it will be the first Easter snow since 1917.  The usual "Where's the warming" is likely to be heard.
Yep, we should see 3-4" or so in NYC, first substantial April snow since 2003 which isn't too crazy, but it is quite uncommon. Models are also showing what could be quite a big storm around the 7th-9th now, possibly with a major portion of it as snow along the seaboard...

While 3-4" isn't too crazy, the repeated nature of this pattern has been! Islip on the east end of Long Island saw its snowiest March on record, in fact, with about 31" for the month.

If the second April event produces 4"+, it would certainly be "wow" worthy (one April event is!).
Title: Re: Northern Hemisphere snow cover
Post by: be cause on April 01, 2018, 08:02:21 PM
.. while here in Ireland a 48 hr blizzard has left the forecast ..
Title: Re: Northern Hemisphere snow cover
Post by: Archimid on April 01, 2018, 10:23:15 PM
Extent is falling as normal even when total snow remains high.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 01, 2018, 10:51:06 PM
Extent is falling as normal even when total snow remains high.
For context, we have about the same extent as we did 12/1/2017, however, the volume over the same scope of coverage is about 3X the depth of what it was at that time!

SWE has taken another uptick today as well, it looks like this year may feature a "head and shoulders" pattern rather than the more typical double-maximum. If so, the departure vs. normal is going to yawn increasingly enormously by 4/15...

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/nh_swe.png)

E.G., if we see conditions that are beneficial to retention as we did last year (but with even more SWE this time around), I think there is actually a decent shot that we are still above 4,000 KM^3 of SWE come 4/15. At that point the difference vs. normal becomes a chasm of many many standard deviations (6 7 or 8 above normal I would think)?, with 98-2011 average SWE for 4/15 at approximately 2,250 KM^3.

We quickly go from 30-40% above normal to about 45% above normal as of 4/1 to 100% above normal by 4/20...

I think May is going to be the month of massive melt this year, not April, and we could still be above 3,500KM ^3 of SWE by 4/30. I would hazard to guess the practical implications of this will be a recurrence of the worsening annual springtime floods across Texas/Louisiana, as well as other random regions of the globe. I would also guess that the resilience on display in Quebec will lead to May snows in New England and maybe even the Mid-Atlantic states.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 01, 2018, 11:11:58 PM
Now here is my next question:

Does the below graph actually show what I ascribe to it in the annotations?

That is, is seasonal snowfall's first maximum determined by rising insolation/the end of winter, while the second maximum (in most years) is driven by the first wave of spring melt -> onset effects thereafter? (latent heat release from melting ice/snow is clearly the driving force behind the enormous and unprecedented 500MB blocking aka "Arctic Amplification" and so as it occurs, the Arctic dumps its cold into the mid-latitudes and the cycle repeats until the cold sources are exhausted).

It is important to separate the noise from useful information when it comes to these changing graphs. If, in fact, this explains the synchronicity to seasonal anomalies, it would stand to reason that as we see higher accumulated SWE, the rebound effects of each melt cycle as spring starts are progressively MORE impactful until we see widespread bare ground, due to the background state of deeper snow. Combined with the lack of Arctic sea ice, this allows quicker "recharging" of the springtime snowpack than ever before, after each episode of melt.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 01, 2018, 11:22:16 PM
Finally... I wonder if we see another hemispheric maximum after 4/1? I think it may actually be possible...!

The snowfall forecasts for the next 10 days show massive falls over the mid-latitudes. The amounts across the U.S. are unprecedented, and will be largely transient, but will bolster gains across Quebec, which saw a bit of melt after a very brief period of heat/moisture this week.

(https://www.tropicaltidbits.com/analysis/models/gem/2018040112/gem_asnow_namer_40.png)

(https://www.tropicaltidbits.com/analysis/models/gfs/2018040112/gfs_asnow_namer_41.png)

The high altitudes of Europe should also be snowy, though lowland regions finally appear to be seeing a respite from winter --

(https://www.tropicaltidbits.com/analysis/models/gem/2018040112/gem_asnow_eu_40.png)

And, finally, there should be sustained large falls across the northern tier of Asia, especially across NW Siberia.

(https://www.tropicaltidbits.com/analysis/models/gem/2018040112/gem_asnow_asia_40.png)

If the maximum is yet to occur, that would be rather crazy.....
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 04, 2018, 09:20:21 AM
I wonder if an imminent flip in seasonal duration between Bering and Hudson Bay could be the driver behind ultimate possible reglaciation? It is interesting to note where the cold normally located in Bering has been displaced and it has been almost entirely over North America, centered precisely over Hudson Bay.

Of course Hudson Bay is likely to melt out regardless, but if this trend accelerates in the coming years, we could see substantially more snow accumulate in winter and spring in adjacent regions to HB, exacerbating Bering's warming further as the thermal gradient with ever-warmer strait warmers are "vacuuming" the North Pacific into the Arctic in the absence of winter sea ice.

This will ultimately spill into both Beaufort and Chukchi. I hesitate to imagine what impact on snowfall will be at that point... I suppose historically it has been sufficient to trigger re-glaciation of the continents.

Real-time actual data is more reliable than low-resolution climate models that miss many potential variables, as Hansen's work shows. And the recent rapid rise in snowfall totals has certainly happened before. Occam's Razor indicates this is how we enter ice ages!  ;D

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)
Title: Re: Northern Hemisphere snow cover
Post by: oren on April 04, 2018, 09:46:30 AM
I wonder if an imminent flip in seasonal duration between Bering and Hudson Bay could be the driver behind ultimate possible reglaciation?
NO
Quote
I suppose historically it has been sufficient to trigger re-glaciation of the continents.
NO
Quote
Occam's Razor indicates this is how we enter ice ages!  ;D
NO

Glaciation happens when snow survives the summer in locations where it didn't use to survive. More snow falling does not trigger glaciation.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 04, 2018, 10:58:56 AM
I wonder if an imminent flip in seasonal duration between Bering and Hudson Bay could be the driver behind ultimate possible reglaciation?
NO
Quote
I suppose historically it has been sufficient to trigger re-glaciation of the continents.
NO
Quote
Occam's Razor indicates this is how we enter ice ages!  ;D
NO

Glaciation happens when snow survives the summer in locations where it didn't use to survive. More snow falling does not trigger glaciation.
....so then what exactly does?!?! you do realize a 3' snowcover in winter would sublimate to nothingness in high-albedo summertime even with frigid cold... without sustained heavy snowfall you cannot developer glaciers, it is the only prerequisite
Title: Re: Northern Hemisphere snow cover
Post by: S.Pansa on April 04, 2018, 11:30:54 AM
Quote
....so then what exactly does?!?!...

Here (http://geosci.uchicago.edu/~archer/reprints/archer.2005.trigger.pdf) is some basic reading for you. Especially recommended,  points [5] to [10] from the first paragraph 1.
Some quotes from the Archer-Paper:

From the Abstract:
Quote
We predict that a carbon release from fossil fuels or methane hydrate deposits of 5000 Gton C could prevent glaciation for the next 500,000 years, until after not one but two 400 kyr cycle eccentricity minima.

Quote
Nucleation of an ice sheet from an interglacial climate is perhaps the easiest part of the glacial cycle to understand and forecast.


Quote
Under preindustrial CO 2 concentration (280matm) ice appears when summertime insolation
(averaged between June 21 and July 20) dropsbelow 455 W/m2, or 0.7 s below the mean, and
grows to full glacial size at very close to this insolation value.


Quote
The nucleation threshold in CLIMBER-2 depends strongly on pCO 2 (Figures 1 and 2), such
that a higher pCO 2 requires a deeper minimum in insolation to trigger glaciation. In addition to the standard 280 matm base case, we ran values of 200, 400, and 560 matm. At 400 matm the trigger decreases to  1.5 s below the mean, and at 560 matm the model will not glaciate at all within a reasonable range of orbital eccentricity (i.e., the trigger insolation is 407 W/m2, more than 3s below the mean). [For those who wonder where we currently are, see 2n attached image (fig 3), current CO2eq aroung 500]

And Fig. 2 and 3, plus an alternative reading of the current snow depth situation.

Or in short:  The an "Ice Age cometh"-nonsense is long debunked. I hope we can go back to discuss more interesting - and real - aspects of snow cover & arctic sea ice (As oren for instance has shown so nicely above)
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 04, 2018, 02:19:16 PM
This might be of interest, published today on The Cryosphere:

Quote
Canadian snow and sea ice: historical trends and projections (https://www.the-cryosphere.net/12/1157/2018/)

Lawrence R. Mudryk1, Chris Derksen1, Stephen Howell1, Fred Laliberté1, Chad Thackeray2, Reinel Sospedra-Alfonso3, Vincent Vionnet4, Paul J. Kushner5, and Ross Brown6

Received: 06 Sep 2017 – Discussion started: 09 Oct 2017
Revised: 09 Feb 2018 – Accepted: 20 Feb 2018 – Published: 04 Apr 2018

Abstract. The Canadian Sea Ice and Snow Evolution (CanSISE) Network is a climate research network focused on developing and applying state of the art observational data to advance dynamical prediction, projections, and understanding of seasonal snow cover and sea ice in Canada and the circumpolar Arctic. Here, we present an assessment from the CanSISE Network on trends in the historical record of snow cover (fraction, water equivalent) and sea ice (area, concentration, type, and thickness) across Canada. We also assess projected changes in snow cover and sea ice likely to occur by mid-century, as simulated by the Coupled Model Intercomparison Project Phase 5 (CMIP5) suite of Earth system models. The historical datasets show that the fraction of Canadian land and marine areas covered by snow and ice is decreasing over time, with seasonal and regional variability in the trends consistent with regional differences in surface temperature trends. In particular, summer sea ice cover has decreased significantly across nearly all Canadian marine regions, and the rate of multi-year ice loss in the Beaufort Sea and Canadian Arctic Archipelago has nearly doubled over the last 8 years. The multi-model consensus over the 2020–2050 period shows reductions in fall and spring snow cover fraction and sea ice concentration of 5–10 % per decade (or 15–30 % in total), with similar reductions in winter sea ice concentration in both Hudson Bay and eastern Canadian waters. Peak pre-melt terrestrial snow water equivalent reductions of up to 10 % per decade (30 % in total) are projected across southern Canada.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 04, 2018, 04:45:35 PM
This might be of interest, published today on The Cryosphere:

Quote
Canadian snow and sea ice: historical trends and projections (https://www.the-cryosphere.net/12/1157/2018/)

Lawrence R. Mudryk1, Chris Derksen1, Stephen Howell1, Fred Laliberté1, Chad Thackeray2, Reinel Sospedra-Alfonso3, Vincent Vionnet4, Paul J. Kushner5, and Ross Brown6

Received: 06 Sep 2017 – Discussion started: 09 Oct 2017
Revised: 09 Feb 2018 – Accepted: 20 Feb 2018 – Published: 04 Apr 2018

Abstract. The Canadian Sea Ice and Snow Evolution (CanSISE) Network is a climate research network focused on developing and applying state of the art observational data to advance dynamical prediction, projections, and understanding of seasonal snow cover and sea ice in Canada and the circumpolar Arctic. Here, we present an assessment from the CanSISE Network on trends in the historical record of snow cover (fraction, water equivalent) and sea ice (area, concentration, type, and thickness) across Canada. We also assess projected changes in snow cover and sea ice likely to occur by mid-century, as simulated by the Coupled Model Intercomparison Project Phase 5 (CMIP5) suite of Earth system models. The historical datasets show that the fraction of Canadian land and marine areas covered by snow and ice is decreasing over time, with seasonal and regional variability in the trends consistent with regional differences in surface temperature trends. In particular, summer sea ice cover has decreased significantly across nearly all Canadian marine regions, and the rate of multi-year ice loss in the Beaufort Sea and Canadian Arctic Archipelago has nearly doubled over the last 8 years. The multi-model consensus over the 2020–2050 period shows reductions in fall and spring snow cover fraction and sea ice concentration of 5–10 % per decade (or 15–30 % in total), with similar reductions in winter sea ice concentration in both Hudson Bay and eastern Canadian waters. Peak pre-melt terrestrial snow water equivalent reductions of up to 10 % per decade (30 % in total) are projected across southern Canada.

I think the echo chamber of incoherent/inaccurate climate modeling is extremely problematic.

RE: snow accumulations vs. necessity of cold when it comes to glaciation --

Accumulated SMB since 9/1 in Greenland is minimal in "cold" areas and the "cold" areas are in fact where the sheet is generally losing mass. The blues? They are on the coast, where it isn't that cold, but the amount of snow has become increasingly prolific.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.dmi.dk%2Fuploads%2Ftx_dmidatastore%2Fwebservice%2Fp%2Fa%2Fm%2Fd%2Fe%2Faccumulatedmap.png&hash=bf11722ea4a828d15f859fee6357ced1)
Title: Re: Northern Hemisphere snow cover
Post by: TerryM on April 04, 2018, 06:12:46 PM
Arguing against a peer reviewed paper with little more than a chart and a hunch is a fools argument.
Terry
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 04, 2018, 06:26:36 PM
Arguing against a peer reviewed paper with little more than a chart and a hunch is a fools argument.
Terry
Those "peers" are byproducts of unbrindled consumerism, which is a direct creation of the supposedly "noble" universities where they are educated. Climate science in liberal society is the equivalent of alchemy in the 1300s. Where do you think the CEOs of Exxon go to school / do you actually think that their friends on the boards/etc would produce anything that refutes a status quo based on low-resolution BS?

Besides real-world graphs of actual ongoing change, the work of Hansen clearly shows those projections to be a farce.

PS latest data from Canadians shows North America is again up in SWE for 4/3 and has once again almost reached its previous maximum.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on April 05, 2018, 02:44:59 AM
Arguing against a peer reviewed paper with little more than a chart and a hunch is a fools argument.
Terry
Those "peers" are byproducts of unbrindled consumerism, which is a direct creation of the supposedly "noble" universities where they are educated. Climate science in liberal society is the equivalent of alchemy in the 1300s. Where do you think the CEOs of Exxon go to school / do you actually think that their friends on the boards/etc would produce anything that refutes a status quo based on low-resolution BS?

Besides real-world graphs of actual ongoing change, the work of Hansen clearly shows those projections to be a farce.

PS latest data from Canadians shows North America is again up in SWE for 4/3 and has once again almost reached its previous maximum.

Christ almighty! Going to go elsewhere to read.
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 05, 2018, 09:50:27 AM
https://www.youtube.com/watch?v=lbVdyPZiOLM
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 05, 2018, 06:46:22 PM
Rutgers:
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on April 05, 2018, 08:18:24 PM
Yes Neven the Rutgers NH snow cover figure for March 2018 was 41.83 million km2. (Anomaly of +1.7 million km2).

Comparison with last 2 years attached.

+ve departures were over New England & US northern plains, eastern and SE Europe. eastern Tibet.

-ve departures were over Turkey and a belt stretching from southern Kazakhstan to Mongolia.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 03:50:47 AM
North America has now reached its maximum seasonal SWE as of 4/4.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

Eurasia beginning to drop more substantially.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/eu_swe.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 06:56:00 AM
...this....is....not....normal.........

(https://www.tropicaltidbits.com/analysis/models/gem/2018040600/gem_asnow_us_40.png)
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 06, 2018, 07:11:24 AM
I found some SWE maps, going back to 2014 (needs a click):
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 07:19:42 AM
I found some SWE maps, going back to 2014:

Scandinavia this year!!! Great maps
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 06, 2018, 07:28:08 AM
And here are the plots (found here (http://www.globsnow.info/swe/), hat-tip to NSIDC):
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 07:35:54 AM
And here are the plots (found here (http://www.globsnow.info/swe/), hat-tip to NSIDC):
Thank you for digging into this... obviously something is actually happening...!

I wonder if a lack of March sea ice in the Bering Sea is a tipping point for the system, as insolation / water vapor impacts begin to cascade?
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 06, 2018, 07:41:33 AM
It's definitely very interesting. I want to try and find some expert to see what he/she thinks.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 08:03:25 AM
And here are the plots (found here (http://www.globsnow.info/swe/), hat-tip to NSIDC):
I think it illustrates how problematic the increase could become over time. The sheer % rise year over year in 2018 is something that is impossible with sea ice because the starting point for NH snow is much lower.

But what about with even more sea ice loss? Does that lead to rapid recurring annual wintertime double digit % losses beginning in the Arctic while we see the same y-o-y increase between 2017->2018 in snowcover also begin to repeat with more frequency?

As the GHG load on the atmosphere increases I think this is a very plausible solution as it is the most effective way for the increased dissipation of planetary heat under ever-increasing GHGs. The increase in heat also comes with an increase in the efficiency of the heat *engine* which is the coupled continental ice sheet-sea ice albedo system.

When the planet is within an ice age, the system responds rapidly to losses in sea ice (i.e. albedo), and with more heat distributed each and every year, *when major extant ice sheets exist* the continents compensate until the annual increase in heat is minimized and the heat engine loses some steam.

Thus I think we must look at the *derivative* of increase rather than the increase itself as another important factor in determining change. When the system is effectively resolving more heat, planetary temps drop, and sea ice begins to form once more.

But as we see several more decades of guaranteed major sustained annual GHG increases, that is not going to happen. Instead, the extra heat is going to be resolved by the destruction of most polar sea ice with new continental ice sheets probably forming by the 2030s. Perhaps the amount of heat injected / natural feedbacks thereafter could be sufficient to plunge the planet into something worse than the last major maximum.

This will have the fortunate side effect of shutting off the primary mechanism behind the GHG releases, however. :)

Food for thought: current record low March NHEM ice volume is approximately 20,000 KM^3. This has dropped from 27,000 KM ^ 3 in 2002 (26%).

This March saw a maximum SWE near 4,500 KM^3. That is about 50% above the normal maximums observed within the past few years. It is a stand out but as years like 2007 and 2012 have shown WRT sea ice, black swans may start as isolated ducklings but they quickly turn into angry honking flocks.

If we roll forward based on a 30% decrease in March ice volume over the next 15 years (probably reasonable based on comp w/02), we end up at 14,000 KM ^ 3 of ice.

Looking at SWE, another 50% increase from 2018 would be approximately 6,750KM ^ 3. Again, we pass 10,000 KM ^3.

What if another major tipping-point is hemispheric snow-water-equivalent surpassing its total volume of sea ice?

We seemingly have answers behind what happened at the end of all the previous ice ages, yet the actual question of onset is always beset by silly thoughts re: solar cycles etc. These are all coincidental to TIPPING POINTS when extant continental ice sheets co-exist with sea ice.
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 06, 2018, 08:42:43 AM
Well, we first need to see whether 2018 is an outlier, and how much longer than normal that snow will linger. I don't know if we can have an ice-free Arctic due to AGW, while at the same time new continental ice sheets start to form. At some point all that extra precipitation starts to fall as rain instead of snow.

I'm interested to see if this is a negative feedback on summer ice melt. Intuition says it will be, but the Arctic has this nasty habit of doing counter-intuitive things.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 08:48:35 AM
Well, we first need to see whether 2018 is an outlier, and how much longer than normal that snow will linger. I don't know if we can have an ice-free Arctic due to AGW, while at the same time new continental ice sheets start to form. At some point all that extra precipitation starts to fall as rain instead of snow.

I'm interested to see if this is a negative feedback on summer ice melt. Intuition says it will be, but the Arctic has this nasty habit of doing counter-intuitive things.
It is a negative feedback of WINTER ice melt. Summer may precipitate the same impact but the snow is falling in March precisely because all that extra precipitation ISN'T falling as rain. And I believe it is derived from the lack of high-latitude sea ice/abundance of increasing polar oceanic heat content.
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on April 06, 2018, 09:46:20 AM
Well, we first need to see whether 2018 is an outlier, and how much longer than normal that snow will linger. I don't know if we can have an ice-free Arctic due to AGW, while at the same time new continental ice sheets start to form. At some point all that extra precipitation starts to fall as rain instead of snow.

I'm interested to see if this is a negative feedback on summer ice melt. Intuition says it will be, but the Arctic has this nasty habit of doing counter-intuitive things.

That is an interesting question. Let's see if we can quantify this.
The SWE (Snow Water Equivalence) this year is high, as we can see in this plot :
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.globsnow.info%2Fswe%2FGCW%2FGCW_Snow_Watch_plot_20180404_SWE_NRT_v1.3.png&hash=777b9e439b4a3b93c116796c795eca81)

For March, it was about 600 Gton above normal.
However, snow cover for March was some 42 million km2 from Rutger's snow lab, as reported by Niall, above.

That is 600 Gton/42 million km2 = 14 kg/m2.
That is only 1.4 cm of ice, folks. It will melt out in a day or two under the right weather conditions.

So, in my opinion, the excess snow water equivalent (SWE) anomaly this year is just a little blimp on the scale, and it won't make any difference for the melting season.

It will all be gone in July, guaranteed.
Title: Re: Northern Hemisphere snow cover
Post by: johnm33 on April 06, 2018, 12:08:13 PM
Just a couple of thoughts, for an ice field to grow it's going to have to be high enough to have late spring/summer snow and large enough to create it's own weather. So I'm thinking it has to be remote from the ocean and with no significant hills/mountains between it and the ocean.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on April 06, 2018, 12:53:20 PM
Thanks Neven for digging those out. (ESA charts)

I was wondering though about the snow cover extent on the 040418 chart. It looks far further north then satellite imagery and NOAA snow chart indicate for the area west of lake Michigan across the Plains.   

I haven't looked elsewhere on the globe to see if there are any other discrepancies.

Title: Re: Northern Hemisphere snow cover
Post by: oren on April 06, 2018, 12:55:52 PM
And here are the plots (found here (http://www.globsnow.info/swe/), hat-tip to NSIDC):
I think it illustrates how problematic the increase could become over time. The sheer % rise year over year in 2018 is something that is impossible with sea ice because the starting point for NH snow is much lower.

But what about with even more sea ice loss? Does that lead to rapid recurring annual wintertime double digit % losses beginning in the Arctic while we see the same y-o-y increase between 2017->2018 in snowcover also begin to repeat with more frequency?

As the GHG load on the atmosphere increases I think this is a very plausible solution as it is the most effective way for the increased dissipation of planetary heat under ever-increasing GHGs. The increase in heat also comes with an increase in the efficiency of the heat *engine* which is the coupled continental ice sheet-sea ice albedo system.

When the planet is within an ice age, the system responds rapidly to losses in sea ice (i.e. albedo), and with more heat distributed each and every year, *when major extant ice sheets exist* the continents compensate until the annual increase in heat is minimized and the heat engine loses some steam.

Thus I think we must look at the *derivative* of increase rather than the increase itself as another important factor in determining change. When the system is effectively resolving more heat, planetary temps drop, and sea ice begins to form once more.

But as we see several more decades of guaranteed major sustained annual GHG increases, that is not going to happen. Instead, the extra heat is going to be resolved by the destruction of most polar sea ice with new continental ice sheets probably forming by the 2030s. Perhaps the amount of heat injected / natural feedbacks thereafter could be sufficient to plunge the planet into something worse than the last major maximum.

This will have the fortunate side effect of shutting off the primary mechanism behind the GHG releases, however. :)

Food for thought: current record low March NHEM ice volume is approximately 20,000 KM^3. This has dropped from 27,000 KM ^ 3 in 2002 (26%).

This March saw a maximum SWE near 4,500 KM^3. That is about 50% above the normal maximums observed within the past few years. It is a stand out but as years like 2007 and 2012 have shown WRT sea ice, black swans may start as isolated ducklings but they quickly turn into angry honking flocks.

If we roll forward based on a 30% decrease in March ice volume over the next 15 years (probably reasonable based on comp w/02), we end up at 14,000 KM ^ 3 of ice.

Looking at SWE, another 50% increase from 2018 would be approximately 6,750KM ^ 3. Again, we pass 10,000 KM ^3.

What if another major tipping-point is hemispheric snow-water-equivalent surpassing its total volume of sea ice?

We seemingly have answers behind what happened at the end of all the previous ice ages, yet the actual question of onset is always beset by silly thoughts re: solar cycles etc. These are all coincidental to TIPPING POINTS when extant continental ice sheets co-exist with sea ice.
Neven thank you for the animations. In terms of extent 2018 seems to be with the high years in North America and with the low years in Siberia, but not exceptional in any case.
As for the quoted post, I don't even know where to begin (again).
Yes we might get more snow depth because of more open water. Will we get more snow extent? It doesn't seem like it.
Will the snow last longer on the ground? My research above, Rob's calculation above, and plain old common sense regarding a warming climate say a strong no.
Does the snow create its own weather? No. The heat comes from elsewhere to melt the snow. An elsewhere where GHGs drive up temps, and there is no albedo effect. The snow is not protected from that heat.

"When the planet is within an ice age, the system responds rapidly to losses in sea ice (i.e. albedo), and with more heat distributed each and every year, *when major extant ice sheets exist* the continents compensate until the annual increase in heat is minimized and the heat engine loses some steam." - so during ice ages the proposed cycle is loss of sea ice leading to growth in continental ice sheets? I say pure fantasy. Sea ice does not shrink while increased glaciation is ongoing, as it is too cold for that. To claim otherwise requires extraordinary proof.

"When the system is effectively resolving more heat, planetary temps drop, and sea ice begins to form once more." - I concur that perhaps the snow is a way for the system to shed some extra heat. But it doesn't cool the system below where it started. It uses some of the excess energy for precipitation, that's all.

"But as we see several more decades of guaranteed major sustained annual GHG increases, that is not going to happen. Instead, the extra heat is going to be resolved by the destruction of most polar sea ice with new continental ice sheets probably forming by the 2030s. Perhaps the amount of heat injected / natural feedbacks thereafter could be sufficient to plunge the planet into something worse than the last major maximum." This defies all common sense. In this theory too much heat causes the continental ice sheets to form. But the snow feedback is not strong enough, cannot be strong enough for that. If it snowed over the whole earth including oceans and equator, and that snow lasted extra time, then perhaps somehow you could get a strong feedback. Pure fantasy.

"We seemingly have answers behind what happened at the end of all the previous ice ages, yet the actual question of onset is always beset by silly thoughts re: solar cycles etc. These are all coincidental to TIPPING POINTS when extant continental ice sheets co-exist with sea ice." Indeed we have answers. Milankovitch cycles. Summers become shorter and cooler, snow lasts on the ground, you get an ice age.

Snow depth is not a feedback in terms of albedo, neither is sea ice volume. The albedo effect is achieved by area multiplied by insolation. NHEM sea ice during insolation season equinox to equinox is currently ~1.5 million km2 less than it was in the 1980s. Is snow extent higher by 1.5 million km2 sustained during the whole season? No. So where is the feedback? Nowhere to be found.

My only serious question, as this is a science forum, is why this "glaciation due to a warming climate" theory is popping up again and again almost on a daily basis. Sorry if I sound harsh, but this does test one's patience, especially as the theory's proponent does seem well versed in science.

Personal resolution: I will try to refrain from posting rebuttals on the subject from now on.
Title: Re: Northern Hemisphere snow cover
Post by: TerryM on April 06, 2018, 02:38:38 PM
If lack of arctic sea ice causes northern glaciation, what were the arctic camels, rhinos, alligators and turtles subsisting on?


I think heavy clouds, fogs and mists kept the far north toasty even in those long months when the sun wasn't shining.


Why wouldn't a similar situation present itself in the near future when we again have blue arctic seas?

Terry
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 06, 2018, 02:46:07 PM
My only serious question, as this is a science forum, is why this "glaciation due to a warming climate" theory is popping up again and again almost on a daily basis. Sorry if I sound harsh, but this does test one's patience, especially as the theory's proponent does seem well versed in science.

bbr2314 is an explorer who wants to be the first and only to discover a new continent. I'm not really into his theory either, but I do appreciate someone looking at the snow intently, as the increased snow fall is highly likely caused by sea ice retreat, which is 1) a consequences that can be bothersome, costly, and even cost lives, and 2) might be a negative feedback of sorts.

If it wasn't for bbr2314's harping, I probably wouldn't have noticed that the SWE situation was out of the ordinary (my recollection is that it has been high for years due to widespread data artifacts over the Tibetan plateau, but not this high). I'm still not 100% sure the graphs are correct, but they likely are. The Canadian ones look dodgy because of tat distribution map with the purple over said Tibetan plateau, and also because I didn't receive any reply to my queries, which suggests no one is really looking after the website (and perhaps the data).

But the Finnish plots and graphs look much more serious and up-to-date, if only for the fact that the NSIDC used them for their latest monthly summary.
Title: Re: Northern Hemisphere snow cover
Post by: TerryM on April 06, 2018, 03:23:26 PM
If local observation is of any use at all.


Here in Southwestern Ontario this year I observed much less snow than in former times, until the last few weeks or so. I could see the grass for all but a few days this winter, however at 9:00 AM on April 6 I've a thin blanket covering everything. I expect it to be gone later today.
I don't recall ever seeing snow in April here.


Our river froze this year for only the third time since 2004. 50 years ago the annual breakup of the ice was a big deal, but it hasn't been an annual occurrence for some time. The Grand River melted about a month ago and the ensuing flooding lead some to remember their childhoods. It again has pockets of very thin ice.


Without consulting any graphs I'd guess that we had a moderate winter, but are suffering a damn cold spring.


Terry
Title: Re: Northern Hemisphere snow cover
Post by: mitch on April 06, 2018, 05:28:09 PM
The snow cover is definitely high this year. However, glaciers grow by the net remaining snow cover, the difference between winter snows and summer melt. Temperate glaciers tend to get more snowfall, but also get more summer melt.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 05:53:42 PM
New high on 4/5. Looks like we may break the graph again?

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 06, 2018, 06:26:09 PM
 And Eurasia and northern hemisphere excluding mountains is going down.

N. America is having really weird weather - but one swallow does not make a summer. Not yet time to make snowballs with Lamar Smith.
Title: Re: Northern Hemisphere snow cover
Post by: Iceismylife on April 06, 2018, 06:35:12 PM
The snow cover is definitely high this year. However, glaciers grow by the net remaining snow cover, the difference between winter snows and summer melt. Temperate glaciers tend to get more snowfall, but also get more summer melt.
Mass gain exceeds mass loss and you grow an ice sheet.

We need more than 1.5m water equivalent in snow fall to grow an ice sheet.  Blue ocean in the arctic mint get that much lake effect snow.
Title: Re: Northern Hemisphere snow cover
Post by: Daniel B. on April 06, 2018, 06:35:54 PM
NH snow cover has increased during the winter months, but decreased during the summer.  The net change has been a slight overall increase.

https://climate.rutgers.edu/snowcover/ (https://climate.rutgers.edu/snowcover/)
Title: Re: Northern Hemisphere snow cover
Post by: Iceismylife on April 06, 2018, 07:05:53 PM
Well, we first need to see whether 2018 is an outlier, and how much longer than normal that snow will linger.
Outlier we had a 4 standard deviation event followed by an over 5SD event in atmospheric angular momentum this winter.  New normal?

My take on how much longer it will linger is not very. If we get on the order of 1.5m of SWE then we can start thinking about year round snow/ice sheet.
I don't know if we can have an ice-free Arctic due to AGW, while at the same time new continental ice sheets start to form. At some point all that extra precipitation starts to fall as rain instead of snow.
High arctic snow 1.5m SWE and we rebuild the continental ice sheet.

I'm interested to see if this is a negative feedback on summer ice melt. Intuition says it will be, but the Arctic has this nasty habit of doing counter-intuitive things.
You said it.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 06, 2018, 10:11:12 PM
It is a question of chicken and egg: is excess oceanic heat leading to the ice loss? Is it atmospheric ridging? Or does the release of latent heat through the daily see-saw of ice formation / loss that must be occurring in this region due to the highest temps on record aid the blocking that then develops overheard?

Whatever the case may be, it certainly seems like the compensating factor becomes an ever-strengthening vortex over Hudson Bay...

Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 07, 2018, 06:42:41 PM
Yayyyyyyy

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 09, 2018, 12:13:23 PM
OK, so part of N. America is having a lot of snow. So did Eurasia. The graphs below show how while snow water equivalent was and still is several SD's greater than average, extent was and is within one SD of average, i.e. melt is delayed by a few days only, certainly less than a week.

A study buried in Environment Canada somewhere dated 2016 says overall snow in Canada has trended down due to warmer winters. One will have to see the extent to which 2017-18 N. America snowfall increase is a trend or just another weird weather event.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on April 09, 2018, 05:01:17 PM
So, to be accurate, Eurasia had a snowy winter. Imagine that.

And then, in the Spring, it will melt.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on April 09, 2018, 05:02:46 PM
I predict that, next winter, it will snow again.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 09, 2018, 05:59:40 PM
I predict that, next winter, it will snow again.
And next winter the ice will form and the following summer it will melt. If you are going to talk down to people because you don't understand how albedo works maybe you should stay on the other side of the forum?

This kind of attitude re: snow falling/melting is inconsiderate & hostile to discourse. It is also especially stupid because all you do is the exact same thing but with sea ice instead of snow.

<Edit Neven: That last sentence spoiled it, and so I've snipped it. Try not to repeat last year's behaviour, and just watch how things play out.>
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 09, 2018, 06:46:18 PM
If modeling is correct North America may still have a ways to go til peak....!!!

Through 4/19:

(https://www.tropicaltidbits.com/analysis/models/gem/2018040912/gem_asnow_namer_40.png)

I think modeling will trend more suppressed with the possible warming event in the mid-range. In any case even with the current look, snowcover over the southern tier will either be stabilized or building. Over the northern shield, it should only be building.

The daily shows a slight gain, perhaps we are at maximum or just about there. If there is another surge I would be surprised, I think the modeling portends a continuation of current SWE or slight increase.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

Even with a continuation, the extant snow-water-mass across North America as of 4/15 will probably be about 2X what it normally is for 4/15. The ultimate impact of this will be continued snows into May and possibly June across some areas (IMO). As we get further into the warm season I believe the worsening albedo differential between Bering + Okhotsk and Hudson + Baffin will trigger continued enormous +500MB anomalies, worsening the standing wave pattern which has been manifesting since the end of February.

The continued rise in SWE across North America is not merely coincidental with what's happening in Bering, it is a major side-effect (downstream winds over open water in April which then advects over continental snows = snow cannon).

I think summer this year will come extremely late for certain parts of the Arctic and North America, namely, anything surrounding the Canadian Shield. Everywhere else is going to torch massively (already happening across parts of Eurasia). Maybe by late August and September the same will happen across North America but I think that even July could be unseasonably cold.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 09, 2018, 08:45:03 PM
The 12z EURO destroys Wisconsin, Minnesota, Michigan and the dense parts of Ontario/upper New England with a crippling ice storm, rivaling the worst in history.

Cataclysmic would be an understatement. This is perhaps the most incredible model output I have ever seen!

https://weather.us/model-charts/euro/2018040912/usa-east/significant-weather/20180415-0300z.html
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 10, 2018, 06:05:06 AM
IF Bering ice drops below a certain threshold, maybe April snows beget May snows?

Or do we have to wait til Beaufort follows?


Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 10, 2018, 08:55:06 AM
I was browsing surface patterns and 2002 and 2003 are actually decent matches to this year (2002 especially). I wonder if that hints at a moderate Nino come fall and a repeat of our snow gains (or worse) into 2019?

In any case, perhaps the differentiating factor between 2018 and 2002 is the abundance of H2O and CO2, with CO2 having risen 10% since then. And the ensuing accumulation of oceanic heat / enlargement of the Hadley Cells.

The 00z EURO maintains and worsens its position from 12z, BTW. The zone of ice now fully ensconces Detroit and Pennsylvania's Upcountry has been added to the mix. If the trend continues expect to see Chicago and NYC next in line.

The below is only snow but is nevertheless impressive in its own right. While there will certainly be melting over the next 10 days, the gains are likely to counter or exceed (IMO).

(https://media.giphy.com/media/L0t4QH22vb3M0RxUPd/giphy.gif)

Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 10, 2018, 09:00:06 PM
Today was a hold. In mid-April, a hold is remarkable in itself. It is spectacular when you are at the highest estimated continental SWE in satellite history.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

I think we may see a slight drop through D2-3 and then a substantial push D4-D6 as the mega-apocalyptic moisture event sprawls across the toes of our largest-ever annual accumulation of snowpack (i.e. a nascent ice sheet).

Perhaps the problem we have now encountered is that IF atmospheric moisture is sufficient, AND sea ice is low enough, the onset of Hadley Cell formation occurs BEFORE snowmelt can manage to begin with vigor, enabling the advection of massive amounts of oceanic heat over areas of the continents covered by snow, where it precipitates out as more snow. This is because the Hadley Cells are driven partially by geography, which is a constant, and the RRR/etc are features of this.

This will likely collapse by mid-May at latest as the atmospheric heat will be sufficient to overwhelm the accumulated snow. But I think moving forward this dynamic will get worse and worse until it is very quickly INSUFFICIENT and we end up snowballing into a rapid-onset ice age in the span of 365 days or less. This is what is happening right now but thank goodness for our massive ongoing atmospheric farts of GHGs which will inevitably still overwhelm the increase, at least this year.

These kinds of anecdotes are illustrative how just how impactful the weather this year has been.

https://twitter.com/wxmvpete/status/983643221266923520/photo/1

Minneapolis has seen its coldest start to April. EVER. And these anomalies are going to widen into the end of the month and possibly into May, until the snow melts out. Until that occurs, and it might not be for several more weeks if the EURO is right, the anomaly is only going to get worse.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 13, 2018, 12:11:18 PM
Hard on the heels of a snowy mega-apocalyptica comes the rain and the warmth.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 13, 2018, 05:56:18 PM
Hard on the heels of a snowy mega-apocalyptica comes the rain and the warmth.
I would not use the GFS for Canada in the spring. CMC then EURO. GFS is terrible at integrating changing snowcover/sea ice (i.e. it doesn't do it at all over the course of its run, it only internalizes the GAINS projected in the models, none of the losses that would result from sensible wx).

Of course, it may be correct, but I would not use it.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 13, 2018, 06:12:33 PM
e.g.

(https://www.tropicaltidbits.com/analysis/models/gem/2018041312/gem_mslp_pcpn_frzn_us_12.png)

(https://www.tropicaltidbits.com/analysis/models/gfs/2018041312/gfs_mslp_pcpn_frzn_us_12.png)

The GFS is good-for-SH*T
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 13, 2018, 06:16:39 PM
I think this may be plausible... it would be NYC's latest measurable on record (or close to it).

(https://www.tropicaltidbits.com/analysis/models/gem/2018041300/gem_mslp_pcpn_frzn_us_26.png)

12z is a bit south

(https://www.tropicaltidbits.com/analysis/models/gem/2018041312/gem_mslp_pcpn_us_23.png)

But I think the imminent situation over SE Canada is likely to yield a 50/50 low that is sufficient to suppress whatever comes behind it into the Mid Atlantic, with the abundance of snowcover over both Quebec and the Midwest/Northeast/New England the other necessary ingredient for late-season snow. Possibly record-breaking. We shall see....!

In other news: North American SWE anomalies are finally dropping. I suspect this may stall D2-3 or even reverse for the last time as we deal with the impending event.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 14, 2018, 10:39:30 PM
https://twitter.com/NWSCaribou/status/984911627010084865/photo/1

It is not coincidental that this is happening at the same time the same records for snow/etc are being set across the entire Canadian Shield...

It is also not coincidental that the Younger Dryas came with the same pattern and with no change/warming over the far SE US. This is exactly what we are now seeing.

I think the CAUSE of the Younger Dryas is what is misunderstood... it was not a shutdown in AMOC, it was an abundance of oceanic heat content and a lack of sea ice that resulted in a temporary period of prolific snows, which THEREAFTER depleted the ocean of its heat content, started sea ice expansion, and pushed the Gulf Stream way S. This did not occur until continental ice sheets began building year-round, which started abruptly (it only takes one year).

My question for everyone here:

We are normally at 1,000 or so KM^3 as of 4/1, in terms of accumulated SWE across North America, according to the Canucks. This takes three months to melt down to zero.

IF we are at 1,250KM^3 as of 5/1 this year (i.e., 250 KM^3+ of ice ABOVE what is normally seen at April, also still more than the seasonal max most years), will it take 3.5 months to melt that ice? Will it take three months? Or will it be unchanged vs normal and all melt out at same time anyways, taking only two months?

I do not think it will be unchanged. An additional month would put melt-out at 8/1 instead of 7/1. Another month and a half would put it at 8/15.

IF we begin to see melt-out extend later in the year, that is when the runaway impact of albedo feedbacks begin to take hold. We are one week away from the same insolation as 8/21, with over 1,500KM^3 of snowpack still accumulated across the continent.

If we can hold onto 1,250KM^3 come 5/1, I think it shows that in the absence of significant Arctic sea ice relative to the 20th Century and in the presence of warmer oceans than ever, weather becomes increasingly stagnant. This is because when sea ice retreats, the "jet stream" falls apart. When this happens in the absence of snowcover, the Hadley Cells deliver heat everywhere. But *if snowcover is still substantial* when the Hadley Cells rear their heads in February and March, the "heads" of the Hadley Cell are much more prone to MAINTAINING cover as massive amounts of heat are advected thanks to the albedo surplus, while the oceanic warmth allows sufficient moisture for near-year-round snows.

This is interesting because as we see more oceanic warming, the Hadley Cells will continue becoming increasingly potent earlier and earlier in the year. This means stagnant weather becomes the norm instead of our old seasons. And this is the natural mechanism that resolves excess oceanic heat content onto the continents in the form of SNOW (i.e. ice sheet expansion). It is not due to the cold that the ice sheets form, it is due to the WARMTH (i.e., MOISTURE).

This year, we are likely to still see full melt-out. It will be late, but it will happen.

But, if next year or in five years, we have 2,000 KM ^3 of SWE across North America on 5/1 -- what happens then? That is a number that would ordinarily take six months to melt under pre-crazy conditions. Will it simply melt faster? Or will enough stay around until August that there is no "summer or fall," with the residual feedbacks of extant snowpack in areas where it normally does not exist during summertime allowing gains to begin again by late August, instead of late October? The act of persistence itself allows the snowpack to build much earlier in the year IF it survives peak insolation....
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 15, 2018, 08:33:27 AM
00z EURO through D5 is...

(https://media.giphy.com/media/mXEofZlzXqIGIB5aRi/giphy.gif)

It has accumulating snow possible in NYC on 4/20...

And today's Canuck graph... the impending event should produce another rise if we have already stalled...!

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

If we hold above 1,400 KM^3 through 5/1 we approach 3X normal SWE for the date... moving forward I suspect this will translate into fortitude for Hudson Bay ice in particular, which is going to be shielded by its blanket of peripheral cover unlike any year previously...

The freshwater release from the melt in May and June is also going to be orders of magnitude above any other years... perhaps come autumn we see a NATL cold spot like never before?
Title: Re: Northern Hemisphere snow cover
Post by: oren on April 15, 2018, 10:42:23 AM
think the CAUSE of the Younger Dryas is what is misunderstood... it was not a shutdown in AMOC, it was an abundance of oceanic heat content and a lack of sea ice that resulted in a temporary period of prolific snows, which THEREAFTER depleted the ocean of its heat content, started sea ice expansion, and pushed the Gulf Stream way S. This did not occur until continental ice sheets began building year-round, which started abruptly (it only takes one year).
The actual science about the Younger Dryas onset, from Wikipedia (https://en.wikipedia.org/wiki/Younger_Dryas#Causes):
The prevailing theory is that the Younger Dryas was caused by significant reduction or shutdown of the North Atlantic "Conveyor", which circulates warm tropical waters northward, in response to a sudden influx of fresh water from Lake Agassiz and deglaciation in North America. Geological evidence for such an event is so far lacking. The global climate would then have become locked into the new state until freezing removed the fresh water "lid" from the North Atlantic. An alternative theory suggests instead that the jet stream shifted northward in response to the changing topographic forcing of the melting North American ice sheet, which brought more rain to the North Atlantic, which freshened the ocean surface enough to slow the thermohaline circulation.

Quote
My question for everyone here:

We are normally at 1,000 or so KM^3 as of 4/1, in terms of accumulated SWE across North America, according to the Canucks. This takes three months to melt down to zero.

IF we are at 1,250KM^3 as of 5/1 this year (i.e., 250 KM^3+ of ice ABOVE what is normally seen at April, also still more than the seasonal max most years), will it take 3.5 months to melt that ice? Will it take three months? Or will it be unchanged vs normal and all melt out at same time anyways, taking only two months?
Unchanged vs. normal, maybe up to 2 weeks more.

Quote
This is interesting because as we see more oceanic warming, the Hadley Cells will continue becoming increasingly potent earlier and earlier in the year. This means stagnant weather becomes the norm instead of our old seasons. And this is the natural mechanism that resolves excess oceanic heat content onto the continents in the form of SNOW (i.e. ice sheet expansion). It is not due to the cold that the ice sheets form, it is due to the WARMTH (i.e., MOISTURE).
No. Ice sheets form because summers are cool enough that snow doesn't melt out.

Quote
But, if next year or in five years, we have 2,000 KM ^3 of SWE across North America on 5/1 -- what happens then? That is a number that would ordinarily take six months to melt under pre-crazy conditions. Will it simply melt faster? Or will enough stay around until August that there is no "summer or fall," with the residual feedbacks of extant snowpack in areas where it normally does not exist during summertime allowing gains to begin again by late August, instead of late October? The act of persistence itself allows the snowpack to build much earlier in the year IF it survives peak insolation....
Recent statistics on this thread showed that higher snows do not result in a later melt-out.
Title: Re: Northern Hemisphere snow cover
Post by: johnm33 on April 15, 2018, 12:19:14 PM
" It is not due to the cold that the ice sheets form, it is due to the WARMTH (i.e., MOISTURE). "
It takes a phenomenal amount of heat to pick up all that water and drop it as snow somewhere far enough from the ocean, and high enough to allow it to survive summer.
I can't remember where I read it, it was years ago [40+?], but the ancients were worried about the spread of ice sheets before the great flood. But they were all catastrophists anyway, at least the ones who tried to communicate with us were, so irrelevent in a uniformitarian world.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 15, 2018, 12:42:41 PM
Meanwhile, Eurasia melts.
Despite the massive additional snow fall in EURASIA (especially Tibet and the Himalaya), extent reduction is less than a week behind average.

I also note that the very very high snow depth anomaly in N America is mainly confined the the NE.
Title: Re: Northern Hemisphere snow cover
Post by: Daniel B. on April 15, 2018, 03:59:20 PM
I think that NA anomaly will change with the recent blizzard that just hit the center of the country.  With record lows and two more storms forecast next week, the snows may linger awhile longer.
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on April 15, 2018, 06:08:51 PM
...........
It is not due to the cold that the ice sheets form, it is due to the WARMTH (i.e., MOISTURE).

bbr2314 as much as I like your covering of snow cover I advise you to focus on more immediate consequences like river discharge, flooding or plant growing season and not on the forming of ice sheets. While it is true that dry conditions prevent ice sheets from forming (e.g. in north Greenland)  North America and Eurasia are still far far away from forming an ice sheet due to increased snow fall.

With a simplistic calculation I would say that we can discuss ice-sheets when the snow water equivalent increased by 500% over today's high numbers. That's 8000 km3 for North America.

I get this number by using melt numbers from Greenland (already a high albedo area)

A = Average Greenland summer melt: 220 km3
B = Average melt area: 342,000 km2 (20% of ice sheet)
=============
A / B =  0.64 m

A = North America snow water equivalent: 1600 km3
B = Snow Cover Extent: 12.000.000 km2
===========
A / B = 0.1333 m

So the already high albedo ice sheet could melt 4.8 times the amount of snow that's currently in North America if it were equal in area. This still ignores vegetation which reduces albedo and that most of the continent consists of low flatland. The low ice sheet regions in Greenland loose mass every year and only survive because they gain ice from the cold central interior.

With this in mind we should probably wait until 10.000-12.000 km3 for North America before ice sheets become a meaningful discussion due to increased snowfall.

data from:
http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/#
https://www.ccin.ca/ccw/snow/current
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on April 15, 2018, 06:32:05 PM
If you wonder how to deal with immense amount of snow just visit Japan  ;)


(https://assets.atlasobscura.com/media/W1siZiIsInVwbG9hZHMvYXNzZXRzL2E3MjAyZWUzN2M5NjZmMzJmM182ODQxMTk3NTU3X2E4MDFiMTQ0Mjlfby5qcGciXSxbInAiLCJjb252ZXJ0IiwiLXF1YWxpdHkgODEgLWF1dG8tb3JpZW50Il0sWyJwIiwidGh1bWIiLCIxMjgweD4iXV0/6841197557_a801b14429_o.jpg)

(https://www.japan-guide.com/g9/7550_01.jpg)

Even these 20m high walls melt out every year in July.

https://www.atlasobscura.com/articles/snow-canyon-japan
https://www.japan-guide.com/e/e7553.html
Title: Re: Northern Hemisphere snow cover
Post by: TerryM on April 15, 2018, 08:38:53 PM
Wow Tealight
That's worse than Buffalo!  ::)


In the earlier post you had mentioned river discharge. Anecdotal evidence, but locally we had the worst spring floods in decades - a month or more ago. Almost all of the accumulated snow, ice, and such has already melted and been flushed out to the lakes.
Whatever runoff we have from here on in will be very late in the season, but there won't be much of it.


Terry - in SW Ontario Canada
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 15, 2018, 09:14:51 PM
If you wonder how to deal with immense amount of snow just visit Japan  ;)


(https://assets.atlasobscura.com/media/W1siZiIsInVwbG9hZHMvYXNzZXRzL2E3MjAyZWUzN2M5NjZmMzJmM182ODQxMTk3NTU3X2E4MDFiMTQ0Mjlfby5qcGciXSxbInAiLCJjb252ZXJ0IiwiLXF1YWxpdHkgODEgLWF1dG8tb3JpZW50Il0sWyJwIiwidGh1bWIiLCIxMjgweD4iXV0/6841197557_a801b14429_o.jpg)

(https://www.japan-guide.com/g9/7550_01.jpg)

Even these 20m high walls melt out every year in July.

https://www.atlasobscura.com/articles/snow-canyon-japan
https://www.japan-guide.com/e/e7553.html

I would argue the situation in Japan is different from the Canadian Shield.

1) Japan is mid-latitude
2) Japan is not proximate to a large fresh-ish body of water that can potentially retain ice through summertime (Hudson Bay). Okhotsk can certainly freeze, but the duration of Okhotsk is no match for HB (even if HB, to date, also melts out every summer).
3) When ice in the Greenland Sea is lacking, easterlies prevail, putting the Canadian Shield down-wind of the coldest airmass in the Hemisphere. Japan lacks an air conditioning unit anywhere near as potent.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 15, 2018, 09:22:41 PM
" It is not due to the cold that the ice sheets form, it is due to the WARMTH (i.e., MOISTURE). "
It takes a phenomenal amount of heat to pick up all that water and drop it as snow somewhere far enough from the ocean, and high enough to allow it to survive summer.
I can't remember where I read it, it was years ago [40+?], but the ancients were worried about the spread of ice sheets before the great flood. But they were all catastrophists anyway, at least the ones who tried to communicate with us were, so irrelevent in a uniformitarian world.

That heat is already manifesting IMO!

I think the below image illustrates my point re: Hawaii as well. Beyond the albedo, I think that this year, we have continued the trend of snowy Himalayas (though they have been WARM, this allows for the snow).

As airmasses move east, the downsloping dries/cools them out over SE Asia/the ocean, which is one of the reasons we have that streak of blues extending east of the continent. On the S side of the blues, the track picks up enormous amounts of heat/moisture.

Once Hawaii is reached, the volcanoes act as a lift cannon, pushing the "suppressed" track NE into North America instead of allowing it to continue straight E. This re-inforces the RRR while delivering another major heat source for NA snows besides the warmth in the NW NATL.

https://physicsworld.com/a/atmosphere-agitated-by-breaking-waves/

Hopefully the below image makes ^ make sense... and if someone can refine my language to be more technical, I would appreciate!

Also: one more amendment -- Wake Island is also apparently important, if you look at the below map, you can see a moderate area of + anomalies above Wake, and then a much larger one above Hawaii. They are both directly correlated to the only land areas between Japan & the West Coast.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 15, 2018, 09:31:11 PM
And SSTs... blazing!

The current event is dumping Caribbean moisture onto Canada btw

https://www.star.nesdis.noaa.gov/GOES/GOES16_CONUS_Band.php?band=GEOCOLOR&length=24
Title: Re: Northern Hemisphere snow cover
Post by: johnm33 on April 16, 2018, 12:09:40 AM
"That heat is already manifesting IMO!"
Not enough to start ice sheets yet by a long way, but recasting the weather systems of N.America very likely imho. My expectations won't begin to manifest until Beaufort is ice free and above 10c year round but we should see signs when it's ice free and a deep low establishes west of Hudson.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 16, 2018, 12:25:31 AM
"That heat is already manifesting IMO!"
Not enough to start ice sheets yet by a long way, but recasting the weather systems of N.America very likely imho. My expectations won't begin to manifest until Beaufort is ice free and above 10c year round but we should see signs when it's ice free and a deep low establishes west of Hudson.
I don't know about that. I think once Bering is ice-free year-round (or nearly so, as it now is), the amount of heat transported into Chukchi/Beaufort is going to increase even more drastically.

You are probably more correct than not, but I suspect the threshold is not +10C year-round, more like the current state of the Bering (re: Beaufort).

Then again, others have said we need 8,000KM^3 of annual SWE to make it through summer. I think this is high. I would think it is on the order of 2,000-2,500KM^3, given the sensible impact an extra 500-1,000KM^3 is having on this April's weather.

Something to consider is that, whenever snow does make it through summer, SWE volume is going to begin increasing in late August instead of mid-October (if it can increase in mid-April, it can do the same in late August, when insolation is similar). Adding another 1.5-2 months to the snow season across the Canadian shield will naturally allow more snow to accumulate by the time spring melt begins to get going. This could mean that if/when we do start to snowball, it happens exceptionally quickly.

It is absolutely nuts that we are just about two months from declining sun angle yet we are still seeing continental gains...

PS: Minneapolis was 28/22 today. They may drop lower overnight. In any case that is an average of 25F on 4/15 (a 22-23F departure). The next five days should sustain similar/slightly warmer averages, all below freezing.

There are many reports that locations in WI/MI/MN are now nearing their all-time snow depths as well.

Truly incredible!

Also: the pattern is actually quite similar to 2013 (maybe another sign that lopsided reformation after massive high latitude losses results/contributes to this crazy)?

Except, as of our current date, the scale for 2018 is... a *tad* lower!

(https://hprcc.unl.edu/products/maps/acis/14dTDeptUS.png)

(https://hprcc.unl.edu/products/maps/acis/Apr13TDeptUS.png)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 16, 2018, 12:48:32 AM
I think once Bering is ice-free year-round (or nearly so, as it now is), the amount of heat transported into Chukchi/Beaufort is going to increase even more drastically.


I think once Bering is ice-free year-round.....

Define ice-free ?

The number of days when Bering Sea ice area is less than 5% of recent years' maxima has increased by about 50 days ( from about 150 days to 200 days) in the period 1979 to 2017. So the Bering Sea on that measure can be considered ice-free for about half the year.

The 2018 low area is an outlier until proved otherwise. One year's data is not a trend.

Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 16, 2018, 03:19:38 AM
I think once Bering is ice-free year-round (or nearly so, as it now is), the amount of heat transported into Chukchi/Beaufort is going to increase even more drastically.


I think once Bering is ice-free year-round.....

Define ice-free ?

The number of days when Bering Sea ice area is less than 5% of recent years' maxima has increased by about 50 days ( from about 150 days to 200 days) in the period 1979 to 2017. So the Bering Sea on that measure can be considered ice-free for about half the year.

The 2018 low area is an outlier until proved otherwise. One year's data is not a trend.

I do not think 2018 is an outlier. It is a new beginning. Just like 2007.

Atmospheric CO2 is now 6% or so above 2007 btw. The forcing for oceanic warmth is mounting which is why the slow decline in the Bering is suddenly... not so slow. There is no way the accumulated heat that has resulted in this year's anomalies can be resolved in a way that results in a recovery (IMO), when more of the same is en route.

Could 2019 be a bit above 2018? Yes. Will it recover beyond 2016-17 levels? I do not think so. Could it be even less than 2018? I think that is probably the most likely option.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 16, 2018, 09:44:21 AM
(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

The blues are spreading.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 18, 2018, 08:51:38 AM
!!!

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018041800/ecmwf_z500aNorm_namer_10.png)

If the recent trends are any indicator, the airmass over Quebec will be 10-15C colder by the time of the event. This may be a record-breaking late season tropical-blizzard hybrid IMO.

And look at the PV plunging south again!!! Substantial NA SWE melt may be delayed to post 5/1.

PS: Canuck SWE shows another day of NA SWE gains! I think we see another 1-2 before we see a few days (or months) of sustained drops.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 18, 2018, 12:46:12 PM
There can be no doubt that the winter of 2107-18 has been a record for snowfall in the Northern hemisphere. There is also no doubt that the procession of snow-storms across North America (into the NE quadrant especially) since the late February amazing Arctic melt is also one for the record books.

This also surely adds to the evidence that a weakened polar vortex is leading to big Rossby waves in turn leading to very unusual, extreme and long-lasting weather events ? However, a single event, by definition cannot be defined as a trend until it is repeated and more than once. We all look for patterns. One pattern could be that there is no longer a pattern - the pace of climate change may have reached the stage that weather is no longer predictable from year to year?

Meanwhile, Eurasia and N. America are showing totally different trends in snow cover.

Eurasia extent loss is just a couple of days behind average, even though SWE is still around 750gt above average (though declining quickly).
In contrast N. America extent loss is about one month behind schedule and going nowhere and SWE is still hovering around the maximum.

However, cci-reanalyzer and weather-forecast.com do both reckon that from the weekend on there will be some very cold days but also days of warmth, sunshine and rain  moving north even into the Canadian Barrens on occasion.

But we will see the reality by May 1st?
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 20, 2018, 06:26:47 AM
Last North American mini-maximum now either underway or likely within a day IMO... we are officially +100% or 2X normal SWE for the date (1,550 KM^3 vs. approx 775 KM^3).

April SWE has so far increased by about 50 KM^3... this has widened the discrepancy from about 500 KM^3 vs. avg as of 3/31. I.E. the departure vs. normal has increased by 55% over the past three-ish weeks.

Rolling forward, if the same departure "schedule" is maintained, it will still result in impending losses. But it would indicate we are probably going to be at or over 1,250KM^3 as of 5/1 (150% of normal). And if gains vs. normal remain steady through May, we will still have approximately 750-800KM^3 of SWE remaining as of 6/1 (vs. 225KM^3 or so normally).

If we are not at or near 1,250KM^3 by 5/1, these estimates will need upward revisions (IMO).

In any case, the dynamic of snow melt this year is going to be far more important far deeper into the season than is normally the case. I do not think May will resolve the anomaly, it is IMO going to take at least the addition of June, and possibly even the entirety of July. It will still be resolved, but the implications for sea ice melt and sensible weather over North America are likely to result in summer extremes that have not been seen in Industrialized History.

This leads me to make one bold prediction: June will be the coldest on record across the upper Midwest and Northeast US. It will also mark the start of a substantial slowdown in the Gulf Stream, a la 2009, but worse. Perhaps I will be wrong, but this should be verifiable! :)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 20, 2018, 10:55:45 AM
I think the melt is starting now in N. America and will continue in Eurasia.
I think the thing to watch will be extent reduction c.f. SWE reduction, i.e. how long will extent reduction be delayed by the SWE anomaly.

I also think that maximum daytime temperatures will be the driver of melt. But that is just my speculation.
Title: Re: Northern Hemisphere snow cover
Post by: Coffee Drinker on April 20, 2018, 10:38:35 PM
Churchill currently +12C and sunny. Strong melt around Hudson at the moment. Next days,however, should see dropping temperatures and blizzard conditions. So snow cover should regenerate for a while.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 21, 2018, 07:27:20 AM
Churchill currently +12C and sunny. Strong melt around Hudson at the moment. Next days,however, should see dropping temperatures and blizzard conditions. So snow cover should regenerate for a while.
It looks like 4/20 may have been the first very strong SWE melt day of the season. Let's see how long it takes to provoke a rebound.

& it was!

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 21, 2018, 11:34:27 AM
From Weather Underground:-

https://www.wunderground.com/news/2018-04-20-snow-cover-meltdown-midwest-satellite

Good Riddance, Winter! Satellite Imagery Reveals Mid-April Snow Cover Rapidly Retreating in the Midwest
Jon Erdman
Published: April 20, 2018

Quote
A fresh cover of snow began retreating almost as fast as it was laid down in parts of the Midwest on Thursday, providing for some spectacular satellite imagery.

A one-two punch from Winter Storm Xanto, then another swath of up to a foot of snow just days later, left an impressive, expansive snowpack by April standards from parts of the Dakotas and northern Nebraska into the Great Lakes by Thursday morning.

In the wake of the second system, sunshine quickly returned to the nation's heartland Thursday.

With the mid-April sun being higher in the sky and able to warm the ground and air above it more efficiently, the snowpack immediately began to melt at its edges, where snow depth was less.

And it was all visible thanks to the GOES-East satellite. Most eye-catching was the snow footprint's southern edge.

Early Thursday morning, snow cover blanketed a swath of northern Illinois, virtually the entire northern half of Iowa, all of Wisconsin, and Lower Michigan almost as far south as Grand Rapids.

See GOES Gif attached

Also looks as though for at least some of the time over the next 5 days real warmth in the high latitudes.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 22, 2018, 10:24:58 AM
Snow extent and SWE as at 21 April from https://www.ccin.ca/ccw/snow/current

What a difference 4 days can make.

North America:- 4 days ago extent loss looked about 30 days behind average. Now it looks about 3 weeks. SWE has also dropped very fast.

Eurasia Extent is reducing pretty much in line with average. the decline in SWE seems to have slowed a bit.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 22, 2018, 03:57:25 PM
NORTH AMERICA SNOW COVER- What happens next.

The cci-renalyzer forecast of temperature over the next 10 days tend to look like the 1st image below, i.e. warmth to the East and th West and cold in the middle reaching as far as the 49th parallel.

The only longer-term temperature forecast for (May, June July) Canada I can find is from Environment Canada (also attached). Normal temperatures in the middle, warmth in the far north, the East and the West. (Weather-forecast.com for the USA has similar but colder in the middle).

So "my prediction that belongs to me" is that the snow is going to go pretty quick - though perhaps in the far north and middle of Canada there will be a couple of weeks delay from normal.

We will see in the next few weeks.
Title: Re: Northern Hemisphere snow cover
Post by: oren on April 23, 2018, 12:12:09 PM
This thread has recently become calmer - a good development.
Here are some more links with data about NA snow cover, with a reminder that albedo is dictated by extent rather than thickness/SWE:

A 30-day animation of snow extent and ice cover (as well as SSTs). The last few days show nicely that when the weather comes, snow can disappear very fast. (click play icon)
https://weather.gc.ca/saisons/animation_e.html?id=month&bc=sea (https://weather.gc.ca/saisons/animation_e.html?id=month&bc=sea)

Another animation of NA snow and Hudson sea ice, with an easier selection of date range and a different map projection.
https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/ (https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/)

An analysis of snow cover extent anomalies, unfortunately only goes to 2010 but still interesting IMO. Clearly shows how fall/winter have positive extent anomalies while spring/summer have negative ones. I expect this trend to have continued to the present.
(https://www.ccin.ca/home/sites/default/files/snow/past/sce_na.png)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 24, 2018, 12:20:48 PM
Snow extent and SWE as at 21 April from https://www.ccin.ca/ccw/snow/current

What a difference 6 days can make. I was expecting a rapid drop, but even so...

North America:- 6 days ago extent loss looked about 30 days behind average. Now it looks about 2 weeks. SWE has also dropped very fast. (Images below).

CC-reanalyzer seems to say that for the remainder of the month in N. America temperatures plus a mixture of rain and clear days at high latitudes should maintain this rapid pace of snow melt.

Watch out for above average river flows and associated ice jams?

PS:- Eurasia Extent and SWE are reducing pretty much in line with average (No images added this time).
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 24, 2018, 04:50:47 PM
Snow extent and SWE as at 21 April from https://www.ccin.ca/ccw/snow/current

What a difference 6 days can make. I was expecting a rapid drop, but even so...

North America:- 6 days ago extent loss looked about 30 days behind average. Now it looks about 2 weeks. SWE has also dropped very fast. (Images below).

CC-reanalyzer seems to say that for the remainder of the month in N. America temperatures plus a mixture of rain and clear days at high latitudes should maintain this rapid pace of snow melt.

Watch out for above average river flows and associated ice jams?

PS:- Eurasia Extent and SWE are reducing pretty much in line with average (No images added this time).

The drop has been ridiculous. But this spring I have noticed when Eurasia or North America tanks, the other steadies. I wonder if we see another pause in NA in the next few days and then Eurasia tanks again?

In either case, the amount of melt this (late) month has been... substantial... and I am re-assured that we must see much more snow accumulate vs currently to sustain snow through July.
Title: Re: Northern Hemisphere snow cover
Post by: Neven on April 25, 2018, 10:52:35 AM
NH snow cover is taking a dive:

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2278.0;attach=100043;image)

And I'm also seeing something I hadn't noticed before. This map doesn't show the extreme snow height (which I would think is correlated to SWE) in Eastern Canada, corresponding with the purple on the Environment Canada SWE anomaly map:

edit: the map background is too dark, here's a http://link (http://www.wetterzentrale.de/pics/Rnhemsnow.gif).

Title: Re: Northern Hemisphere snow cover
Post by: oren on April 25, 2018, 12:19:07 PM
I believe the thick snow is still there. Here is the (very hard to read) Environment Canada snow depth map, showing 160-210 cm snow depth across parts of Quebec.

I've also taken the opportunity to update the three snow depth charts I've made in mid-March of specific SYNOP stations (Goose Bay and Cartwright in Canada, Sredne-Kolymsk in Russia). The updated charts show, again, that winter snow depth during winter is not very predictive of spring snow depth, in opposition to certain predictions posted in this thread.

Deep land snow seems to be a consequence of AGW. For people living with all that snow I am sure it's a severe consequence, but it does not create a significant climate feedback.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on April 25, 2018, 02:13:11 PM
NH snow cover is taking a dive:

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2278.0;attach=100043;image)



And looking at the chart, we see that NH snow extent was actually tracking with the lowest years until late February and March when extent grew dramatically. I believe heavier snowfall in the winter is a new feature of AGW (more moisture load in the atmosphere etc.) but the phenomenon  this April is simply weather IMHO.
Title: Re: Northern Hemisphere snow cover
Post by: Daniel B. on April 25, 2018, 03:01:34 PM
Whether the heavy snowfall is a consequence or not is rather contentious.  More moisture will generate greater snowfall in those areas where sufficient cold exists.  However, many areas will see more snow transition to rain, as temperatures rise.  The premise is that the rain/snow edge should move further poleward, with areas in higher latitudes receiving greater snowfall, and those in lower receiving less.  The thought is that more snow would fall in the depths of winter, as moisture invades the drier air, while spring and fall receive less, due to temperatures rising above freezing.  This past year shows the opposite.  Hence, I agree that it was probably just weather.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 26, 2018, 10:23:33 AM
Snow extent and SWE as at 25 April from https://www.ccin.ca/ccw/snow/current

I was expecting the rapid drop to continue, but even so...

North America:- 8 days ago extent loss looked about 30 days behind average. Now it looks about 10 days. SWE has also dropped very, very fast. (Images below).

CC-reanalyzer still seems to say that for the remainder of the month and the first few days in May  N. America temperatures will be above zero for most of the time except the for centre of Northern Canada.  And a mixture of rain and clear days at high latitudes should maintain this rapid pace of snow melt.

Above average river flows and associated ice jams?

PS:- Eurasia Extent following the 1 SD above average line while SWE well above average but reducing pretty much in line with average (No images added this time).
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on April 26, 2018, 11:56:01 PM
The high anomalous snow cover in eastern Canada is getting torched today. Not only is it above freezing, it is also very humid and raining. The best mix to melt snow effectively.

Short Energy comparison
liquid water 1 degree change: 4.18 J/g
Enthalpy of fusion: 333 J/g
Enthalpy of vaporization: 2257 J/g
(energy wise 1 gram of water vapor can melt 6.7 gram of ice)

Just before the shoreline the air contains 30 kg/m2 of water vapor and a bit further inland it drops to 20 kg/m2. With a perfect energy transfer (unlikely) it could melt 6.7 cm of ice. I can't calculate how much energy gets really transferred because the wind speed and direction varies significantly in the lower parts of the atmosphere.

I didn't manage to line up the green dot in my gif but all shown values are for the same location.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 27, 2018, 11:55:13 AM
Can't resist the graphs on https://www.ccin.ca/ccw/snow/current.

Goodbye to the snow in N. America. In the next few days I still say it is periods of warmth that matter more than cold nights for snow melt. Last image is maximum temperatures over the next 5 days. t says melting to very high latitudes to me. We will see.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 27, 2018, 05:08:22 PM
Can't resist the graphs on https://www.ccin.ca/ccw/snow/current.

Goodbye to the snow in N. America. In the next few days I still say it is periods of warmth that matter more than cold nights for snow melt. Last image is maximum temperatures over the next 5 days. t says melting to very high latitudes to me. We will see.
I think the speed with which the anomalies are resolving is another indicator the graphs are indeed accurate. And the sudden surge in melt is almost as anomalous as the first half of April!
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 28, 2018, 12:02:25 PM
Still can't resist the graphs on https://www.ccin.ca/ccw/snow/current.
Title: Re: Northern Hemisphere snow cover
Post by: be cause on April 28, 2018, 12:48:45 PM
cheers Gerontocrat .. it's not often you see a whole Ice Age disappear in a week ! :) .. along with the all-pervasive commentary .. b.c.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 28, 2018, 01:04:31 PM
cheers Gerontocrat .. it's not often you see a whole Ice Age disappear in a week ! :) .. along with the all-pervasive commentary .. b.c.

The data in the end has the last word (until next winter and spring?)
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on April 28, 2018, 04:38:40 PM
cheers Gerontocrat .. it's not often you see a whole Ice Age disappear in a week ! :) .. along with the all-pervasive commentary .. b.c.

The data in the end has the last word (until next winter and spring?)

The data always has the last word. Snowfall in the late winter and early Spring in NA was huge. The current melt is rapid. We have generally been seeing positive snowfall anomalies in the Fall and early winter and negative anomalies in the Spring, more than just a single season. It would be great if scientists would begin to definitively link the changes that we are seeing in weather with AGW.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 28, 2018, 11:13:44 PM
cheers Gerontocrat .. it's not often you see a whole Ice Age disappear in a week ! :) .. along with the all-pervasive commentary .. b.c.

The data in the end has the last word (until next winter and spring?)

The data always has the last word. Snowfall in the late winter and early Spring in NA was huge. The current melt is rapid. We have generally been seeing positive snowfall anomalies in the Fall and early winter and negative anomalies in the Spring, more than just a single season. It would be great if scientists would begin to definitively link the changes that we are seeing in weather with AGW.
Indeed. At the very least, I am glad the melt has begun -- but as always, it has happened in a way almost as surprising as the great lengthening of peak SWE this year.

We have lost the same SWE that it normally takes ~36 days to melt in only six days. I suspect that this will translate into extreme cold and snow anomalies persisting into May and June as we still do have positive residuals, but they are imminently going to be coupled with a fairly abrupt freshwater pulse.

My suspicion is that these freshwater pulses (like we saw in the ante-Nino months of 2009...) result in more of the AMOC's energy translating upstream into the waters near Svalbard / also result in heat discharge into Greenland, thus encouraging +500MB anomalies in both regions and causing "-NAO".

If the 12z EURO is correct, the extended forecast is looking... rather anomalous... once more. Let's hope it doesn't severely impact the start of spring now underway across the Heartland / Great Plains.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018042812/ecmwf_z500_mslp_nhem_11.png)

^ is also a very terrible look for the sea ice...
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 29, 2018, 01:00:27 PM
Still can't resist the graphs on https://www.ccin.ca/ccw/snow/current.
Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on April 29, 2018, 02:59:24 PM
Will SWE (snow water equivalent) get below +1 S.D. before May 1st?  I'm guessing 'no' by a hair. 

In other news:  Who would 'a thought that snow would melt in the spring?  ::)  Response:  Well, those who expect recent precedent is predictive.

[Edit on May 9th:  It was "no", but it was off by more than a hair!]
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on April 29, 2018, 03:11:53 PM
Will SWE (snow water equivalent) get below +1 S.D. before May 1st?  I'm guessing 'no' by a hair. 

In other news:  Who would 'a thought that snow would melt in the spring?  ::)  Response:  Well, those who expect recent precedent is predictive.
This is like a "denier" saying "who would've though ice would melt in summer?"

Who would have thought we would see normal April SWE losses in only 5 days or so?  ::)

I *never* said we would see snow make it through summer this yr. I was wrong on how long it took to melt out.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on April 29, 2018, 04:02:20 PM
Will SWE (snow water equivalent) get below +1 S.D. before May 1st?  I'm guessing 'no' by a hair. 

In other news:  Who would 'a thought that snow would melt in the spring?  ::)  Response:  Well, those who expect recent precedent is predictive.
This is like a "denier" saying "who would've though ice would melt in summer?"

Who would have thought we would see normal April SWE losses in only 5 days or so?  ::)

I *never* said we would see snow make it through summer this yr. I was wrong on how long it took to melt out.

Looking at N. America temps on cci-reanalyzer mu guess is SWE will get just inside the 1SD line on April 30
BUT
later on it looks as if the last bit of snow in central northern canada to the far northern east coast may be somewhat obstinate.

BUT - I've a better chance of predicting what Trump is going to tweet tomorrow.
Title: Re: Northern Hemisphere snow cover
Post by: Archimid on April 30, 2018, 02:01:07 PM
So I guess the coming ice age is canceled.  Who would've thought.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 01, 2018, 04:20:32 AM
So I guess the coming ice age is canceled.  Who would've thought.
Incorrect. It won't be this year. I didn't say it would be. But it is coming!

If this year is not a black swan, the mid April SWE # is a 1,600KM^3 increase over early 2000s (2,200KM^3 vs. 3,800KM^3).

When considering sea ice volume in the same time has dropped from 27,000 to 22,800KM^3, it shows an extremely rapid shift in the balance of the annual crysophere: the % that was comprised of SWE rose from 7.5% fifteen years ago to 13.5% today.

It does not matter that the sea ice is dropping (or rather, this may be a direct cause of the shifting balance). But it is extremely alarming because if we see a continuation of what has occurred since 2000, ongoing wintertime ice mass loss will be accompanied by an ever-growing amount of springtime SWE.

If recent trends are an indicator, by the early 2030s, SWE will take up approximately 24% of the annual balance of the cryosphere. By 2035, there will be a year that reaches 6,000 KM ^3 of accumulated SWE while simultaneously seeing an April ice volume of 17,000-18,000 KM ^ 3.  Both of these figures (gains and losses) may be conservative based on the recent acceleration in stagnant weather/etc since 2011-2012.

I think, at that point (nearing 2X record SWE of this year), we will begin to see severe winter impacts last far deeper into summer for prone regions, while general wintertime weather continues to worsen for the mid-latitudes.

Coincidentally, or not, NYC's average snow has increased at a rate that mirrors the hemispheric adjustments since the early 2000s. If this is matched moving forward, it is likely that the city's new median/average approaching 40"+ is only going to keep rising, possibly reaching into the 60s+ by the 2030s.
Title: Re: Northern Hemisphere snow cover
Post by: Human Habitat Index on May 01, 2018, 06:04:37 AM
Polar Amplification -> Wavy Jetstreams -> Warming Arctic -> SSW -> Polar Vortex Displacement ->
Cryosphere Displacement -> Loss of Sea Ice -> Gain in SWE.

It doesn't have to be an Ice Age, just the delay and disruption to seeding the North American Bread Basket is bad enough.

Saw on the Al Jazeera "banner" that wheat drilling has been delayed this year.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 01, 2018, 07:34:33 AM
Polar Amplification -> Wavy Jetstreams -> Warming Arctic -> SSW -> Polar Vortex Displacement ->
Cryosphere Displacement -> Loss of Sea Ice -> Gain in SWE.

It doesn't have to be an Ice Age, just the delay and disruption to seeding the North American Bread Basket is bad enough.

Saw on the Al Jazeera "banner" that wheat drilling has been delayed this year.
This led to the Syrian Civil War after things began accelerating between the 2007 and 2012 melt events. Now we will add snowfall as another factor simultaneously worsening at a rate that is accelerating even more dramatically. The April 2018 temperature anomaly maps are extraordinary. I think it is even more telling that the comparison with 2013 in the US is extremely close (which followed the 2012 ice-out, and ensuing snows).

If the events of 2012-13->2013-14 are repeated, I suspect we see an even worse SWE event next winter, and then a temporary reprieve. But if 2012-13 was the analogy to NYC's snow this winter (26.1" vs. 40.9") then we may see the snowiest winter on record next year (the same % increase would result in almost 90" for the year in the Park). I think that is very aggressive but possible given what we saw in Boston in 2014-15 and DC in 2009-10.

If this is a "new normal" it also portends a possible end to the 2012-esque drops in sea ice, instead replaced by more continuous year to year momentum that still puts us on the same curve, just without as much summertime variability. That means 2012 #s are likely to begin occurring every year, but that the odds of a "Blue Arctic" event may actually be declining as the SWE input kicks into higher gear each passing winter.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 01, 2018, 09:15:34 AM
Rutgers monthly #s out, show similar to 4/2013.

Interesting to note the Himalayas are also standing out. Perhaps the Canuck purples there aren't imaginary either.

I suspect as we hurtle past solstice, the ongoing Himalayan anomaly will assist in atmospheric heat transport both to the south (ending up in Bering) and to the N (ending up in Siberian Seas).
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 01, 2018, 10:12:50 AM
So I guess the coming ice age is canceled.  Who would've thought.
Incorrect. It won't be this year. I didn't say it would be. But it is coming!

But it is extremely alarming because if we see a continuation of what has occurred since 2000, ongoing wintertime ice mass loss will be accompanied by an ever-growing amount of springtime SWE.

If recent trends are an indicator, by the early 2030s, SWE will take up approximately 24% of the annual balance of the cryosphere. By 2035, there will be a year that reaches 6,000 KM ^3 of accumulated SWE

I think, at that point (nearing 2X record SWE of this year), we will begin to see severe winter impacts last far deeper into summer for prone regions, while general wintertime weather continues to worsen for the mid-latitudes.

I cannot find a science paper to support your contention that Northern Hemisphere SWE or extent is on an upward trend since 2000. Rather the papers I found seem to talk about reductions though highly variable according to latitude (& longitude?) and elevation.

https://link.springer.com/article/10.1007%2Fs40641-016-0036-8
Quote
Trends and Extremes in Northern Hemisphere Snow Characteristics
Abstract

Recent studies of snow climatology show a mix of trends but a preponderance of evidence suggest an overall tendency toward decreases in several metrics of snow extremes. The analysis performed herein on maximum seasonal snow depth points to a robust negative trend in this variable for the period of winter 1960/1961–winter 2014/2015. This conclusion is applicable to North America. Maximum snow depth is also mostly decreasing for those European stations analyzed. Research studies show generally negative trends in snow cover extent and snow water equivalent across both North America and Eurasia. These results are mostly, but not fully, consistent with simple hypotheses for the effects of global warming on snow characteristics.

www.mdpi.com/2072-4292/10/1/136/pdf
by Y Wang - ‎2018 et al
Tracking Snow Variations in the Northern
Hemisphere Using Multi-Source Remote Sensing
Data (2000–2015)
by Y Wang - ‎2018 et al

Quote
Abstract: Multi-source remote sensing data were used to generate 500-m resolution cloud-free daily snow cover images for the Northern Hemisphere. Simultaneously, the spatial and temporal dynamic variations of snow in the Northern Hemisphere were evaluated from 2000 to 2015. The results indicated that
(1) the maximum, minimum, and annual average snow-covered area (SCA) in the Northern Hemisphere exhibited a fluctuating downward trend; the variation of snow cover in the Northern Hemisphere had well-defined inter-annual and regional differences;
(2) the average SCA in the Northern Hemisphere was the largest in January and the smallest in August; the SCA exhibited a downward trend for the monthly variations from February to April; and the seasonal variation in the SCA exhibited a downward trend in the spring, summer, and fall in the Northern Hemisphere (no pronounced variation trend in the winter was observed) during the 2000–2015 period;
(3) the spatial distribution of the annual average snow-covered day (SCD) was related to the latitudinal zonality, and the areas exhibiting an upward trend were mainly at the mid to low latitudes with unstable SCA variations; and
(4) the snow reduction was significant in the perennial SCA in the Northern Hemisphere, including high-latitude and high-elevation mountainous regions (between 35◦ and 50◦N), such as the Tibetan Plateau, the Tianshan Mountains, the Pamir Plateau in Asia, the Alps in Europe, the Caucasus Mountains, and the Cordillera Mountains in North America.
Title: Re: Northern Hemisphere snow cover
Post by: oren on May 01, 2018, 10:29:03 AM
So I guess the coming ice age is canceled.  Who would've thought.
Incorrect. It won't be this year. I didn't say it would be. But it is coming!

If this year is not a black swan, the mid April SWE # is a 1,600KM^3 increase over early 2000s (2,200KM^3 vs. 3,800KM^3).

...ever-growing amount of springtime SWE.

I think, at that point (nearing 2X record SWE of this year), we will begin to see severe winter impacts last far deeper into summer for prone regions
I really expected you to lay off this nonsense. Haven't learned anything from this year's spectacular behavior. Assuming you are correct and wintertime+April SWE is on the rise in the NH - the only thing that will happen is extreme melt in May. No ice age, no negative feedback on climate. The data shows it - when wintertime snow accumulation is high, springtime melt is high, with melt-out date more or less unchanged. So if you're going to continue with these baseless predictions, maybe you should come up with better arguments. Scientific papers modelling your predictions? Specific locations where this change in melt-out into summer actually occurred? Just repeating your fantastic prediction ad nauseum gets nowhere.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 01, 2018, 11:14:43 AM
Meanwhile, back at the data..........

As expected, snow continues to melt. A slight slow-down in N. America as it is somewhat chilly in the far north and middle.
Title: Re: Northern Hemisphere snow cover
Post by: Archimid on May 01, 2018, 02:35:08 PM
Quote
Incorrect. It won't be this year. I didn't say it would be. But it is coming!

Yes it's coming for sure once CO2 gets to around 200ppm, in 30k-40k years.

Quote
It does not matter that the sea ice is dropping (or rather, this may be a direct cause of the shifting balance). But it is extremely alarming because if we see a continuation of what has occurred since 2000, ongoing wintertime ice mass loss will be accompanied by an ever-growing amount of springtime SWE.

Correct, but that spring time SWE is not even close to enough to hold the snow through summer. Not even close even at record high levels of snow fall.  However it is enough to make winter miserable and the beginning of summer very flood prone.

Quote
If recent trends are an indicator, by the early 2030s, SWE will take up approximately 24% of the annual balance of the cryosphere. By 2035, there will be a year that reaches 6,000 KM ^3 of accumulated SWE while simultaneously seeing an April ice volume of 17,000-18,000 KM ^ 3.  Both of these figures (gains and losses) may be conservative based on the recent acceleration in stagnant weather/etc since 2011-2012

By 2030 a significant part of that water will fall as rain, not snow. However, I do expect to be below the freezing point for long enough to get lots of snow in very little time. But even if temperatures remained the same, snow at the levels you describe by 2030 won't be enough to last May, let alone the summer.

Quote
I think, at that point (nearing 2X record SWE of this year), we will begin to see severe winter impacts last far deeper into summer for prone regions, while general wintertime weather continues to worsen for the mid-latitudes.


Yes but the areas were the former happen will be very small and the areas were the latter happen will be very large.

Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 01, 2018, 02:58:24 PM
So I guess the coming ice age is canceled.  Who would've thought.
Incorrect. It won't be this year. I didn't say it would be. But it is coming!

If this year is not a black swan, the mid April SWE # is a 1,600KM^3 increase over early 2000s (2,200KM^3 vs. 3,800KM^3).

...ever-growing amount of springtime SWE.

I think, at that point (nearing 2X record SWE of this year), we will begin to see severe winter impacts last far deeper into summer for prone regions
I really expected you to lay off this nonsense. Haven't learned anything from this year's spectacular behavior. Assuming you are correct and wintertime+April SWE is on the rise in the NH - the only thing that will happen is extreme melt in May. No ice age, no negative feedback on climate. The data shows it - when wintertime snow accumulation is high, springtime melt is high, with melt-out date more or less unchanged. So if you're going to continue with these baseless predictions, maybe you should come up with better arguments. Scientific papers modelling your predictions? Specific locations where this change in melt-out into summer actually occurred? Just repeating your fantastic prediction ad nauseum gets nowhere.
To say "because something is currently happening" and therefore it will continue in the future ignores what the future will entail.

If we get to 6,000 KM ^3 of SWE by mid-April, we would need *3,000* KM^3 of melt in 30 days to get below 3,000KM^3 by mid-May. That would still leave something like 6-7X normal SWE for early 2000s.

At that point, we sacrifice June to melt as well. There is still probably enough heat to ensure annual melt-out in most regions, but if we get to 9,000-12,000KM^3 of SWE... there may not be. Long before the latter point, harvests in the grain belts will begin failing, perhaps the collapse of agriculture/ensuing drop in aerosols from industrial collapse would be sufficient to spike global temps / cause bluest Arctic event yet / result in ensuing spiral.
Title: Re: Northern Hemisphere snow cover
Post by: Daniel B. on May 01, 2018, 03:30:23 PM
So I guess the coming ice age is canceled.  Who would've thought.
Incorrect. It won't be this year. I didn't say it would be. But it is coming!

But it is extremely alarming because if we see a continuation of what has occurred since 2000, ongoing wintertime ice mass loss will be accompanied by an ever-growing amount of springtime SWE.

If recent trends are an indicator, by the early 2030s, SWE will take up approximately 24% of the annual balance of the cryosphere. By 2035, there will be a year that reaches 6,000 KM ^3 of accumulated SWE

I think, at that point (nearing 2X record SWE of this year), we will begin to see severe winter impacts last far deeper into summer for prone regions, while general wintertime weather continues to worsen for the mid-latitudes.

I cannot find a science paper to support your contention that Northern Hemisphere SWE or extent is on an upward trend since 2000. Rather the papers I found seem to talk about reductions though highly variable according to latitude (& longitude?) and elevation.

https://link.springer.com/article/10.1007%2Fs40641-016-0036-8
Quote
Trends and Extremes in Northern Hemisphere Snow Characteristics
Abstract

Recent studies of snow climatology show a mix of trends but a preponderance of evidence suggest an overall tendency toward decreases in several metrics of snow extremes. The analysis performed herein on maximum seasonal snow depth points to a robust negative trend in this variable for the period of winter 1960/1961–winter 2014/2015. This conclusion is applicable to North America. Maximum snow depth is also mostly decreasing for those European stations analyzed. Research studies show generally negative trends in snow cover extent and snow water equivalent across both North America and Eurasia. These results are mostly, but not fully, consistent with simple hypotheses for the effects of global warming on snow characteristics.

www.mdpi.com/2072-4292/10/1/136/pdf
by Y Wang - ‎2018 et al
Tracking Snow Variations in the Northern
Hemisphere Using Multi-Source Remote Sensing
Data (2000–2015)
by Y Wang - ‎2018 et al

Quote
Abstract: Multi-source remote sensing data were used to generate 500-m resolution cloud-free daily snow cover images for the Northern Hemisphere. Simultaneously, the spatial and temporal dynamic variations of snow in the Northern Hemisphere were evaluated from 2000 to 2015. The results indicated that
(1) the maximum, minimum, and annual average snow-covered area (SCA) in the Northern Hemisphere exhibited a fluctuating downward trend; the variation of snow cover in the Northern Hemisphere had well-defined inter-annual and regional differences;
(2) the average SCA in the Northern Hemisphere was the largest in January and the smallest in August; the SCA exhibited a downward trend for the monthly variations from February to April; and the seasonal variation in the SCA exhibited a downward trend in the spring, summer, and fall in the Northern Hemisphere (no pronounced variation trend in the winter was observed) during the 2000–2015 period;
(3) the spatial distribution of the annual average snow-covered day (SCD) was related to the latitudinal zonality, and the areas exhibiting an upward trend were mainly at the mid to low latitudes with unstable SCA variations; and
(4) the snow reduction was significant in the perennial SCA in the Northern Hemisphere, including high-latitude and high-elevation mountainous regions (between 35◦ and 50◦N), such as the Tibetan Plateau, the Tianshan Mountains, the Pamir Plateau in Asia, the Alps in Europe, the Caucasus Mountains, and the Cordillera Mountains in North America.

I think the difference can be attributed to how the recent trend is defined.  Choosing a start date in the 60s or 70s, when the snowpack was deeper and more extensive, yields the negative trends, as shown in your references.  However, choosing just the past thirty years, will generating a positive trend. 

https://nsidc.org/cryosphere/sotc/snow_extent.html (https://nsidc.org/cryosphere/sotc/snow_extent.html)

The seasonality of the snowfall has shown greater disparity.  NH snow cover has increased from October through January, but decreased from March to August.

https://www.ncdc.noaa.gov/snow-and-ice/extent/snow-cover/nhland/12 (https://www.ncdc.noaa.gov/snow-and-ice/extent/snow-cover/nhland/12)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 01, 2018, 03:52:26 PM
So I guess the coming ice age is canceled.  Who would've thought.
Incorrect. It won't be this year. I didn't say it would be. But it is coming!

But it is extremely alarming because if we see a continuation of what has occurred since 2000, ongoing wintertime ice mass loss will be accompanied by an ever-growing amount of springtime SWE.

If recent trends are an indicator, by the early 2030s, SWE will take up approximately 24% of the annual balance of the cryosphere. By 2035, there will be a year that reaches 6,000 KM ^3 of accumulated SWE

I think, at that point (nearing 2X record SWE of this year), we will begin to see severe winter impacts last far deeper into summer for prone regions, while general wintertime weather continues to worsen for the mid-latitudes.

I cannot find a science paper to support your contention that Northern Hemisphere SWE or extent is on an upward trend since 2000. Rather the papers I found seem to talk about reductions though highly variable according to latitude (& longitude?) and elevation.

https://link.springer.com/article/10.1007%2Fs40641-016-0036-8
Quote
Trends and Extremes in Northern Hemisphere Snow Characteristics
Abstract

Recent studies of snow climatology show a mix of trends but a preponderance of evidence suggest an overall tendency toward decreases in several metrics of snow extremes. The analysis performed herein on maximum seasonal snow depth points to a robust negative trend in this variable for the period of winter 1960/1961–winter 2014/2015. This conclusion is applicable to North America. Maximum snow depth is also mostly decreasing for those European stations analyzed. Research studies show generally negative trends in snow cover extent and snow water equivalent across both North America and Eurasia. These results are mostly, but not fully, consistent with simple hypotheses for the effects of global warming on snow characteristics.

www.mdpi.com/2072-4292/10/1/136/pdf
by Y Wang - ‎2018 et al
Tracking Snow Variations in the Northern
Hemisphere Using Multi-Source Remote Sensing
Data (2000–2015)
by Y Wang - ‎2018 et al

Quote
Abstract: Multi-source remote sensing data were used to generate 500-m resolution cloud-free daily snow cover images for the Northern Hemisphere. Simultaneously, the spatial and temporal dynamic variations of snow in the Northern Hemisphere were evaluated from 2000 to 2015. The results indicated that
(1) the maximum, minimum, and annual average snow-covered area (SCA) in the Northern Hemisphere exhibited a fluctuating downward trend; the variation of snow cover in the Northern Hemisphere had well-defined inter-annual and regional differences;
(2) the average SCA in the Northern Hemisphere was the largest in January and the smallest in August; the SCA exhibited a downward trend for the monthly variations from February to April; and the seasonal variation in the SCA exhibited a downward trend in the spring, summer, and fall in the Northern Hemisphere (no pronounced variation trend in the winter was observed) during the 2000–2015 period;
(3) the spatial distribution of the annual average snow-covered day (SCD) was related to the latitudinal zonality, and the areas exhibiting an upward trend were mainly at the mid to low latitudes with unstable SCA variations; and
(4) the snow reduction was significant in the perennial SCA in the Northern Hemisphere, including high-latitude and high-elevation mountainous regions (between 35◦ and 50◦N), such as the Tibetan Plateau, the Tianshan Mountains, the Pamir Plateau in Asia, the Alps in Europe, the Caucasus Mountains, and the Cordillera Mountains in North America.

I think the difference can be attributed to how the recent trend is defined.  Choosing a start date in the 60s or 70s, when the snowpack was deeper and more extensive, yields the negative trends, as shown in your references.  However, choosing just the past thirty years, will generating a positive trend. 

https://nsidc.org/cryosphere/sotc/snow_extent.html (https://nsidc.org/cryosphere/sotc/snow_extent.html)

The seasonality of the snowfall has shown greater disparity.  NH snow cover has increased from October through January, but decreased from March to August.

https://www.ncdc.noaa.gov/snow-and-ice/extent/snow-cover/nhland/12 (https://www.ncdc.noaa.gov/snow-and-ice/extent/snow-cover/nhland/12)

Eurasia is seemingly a bit slower to respond but in North America, after 2018, the trend in April is undeniable, I would say it has now firmly flipped from "warmer" to "colder".

Title: Re: Northern Hemisphere snow cover
Post by: oren on May 01, 2018, 04:17:49 PM
To say "because something is currently happening" and therefore it will continue in the future ignores what the future will entail.

If we get to 6,000 KM ^3 of SWE by mid-April, we would need *3,000* KM^3 of melt in 30 days to get below 3,000KM^3 by mid-May. That would still leave something like 6-7X normal SWE for early 2000s.

At that point, we sacrifice June to melt as well. There is still probably enough heat to ensure annual melt-out in most regions, but if we get to 9,000-12,000KM^3 of SWE... there may not be. Long before the latter point, harvests in the grain belts will begin failing, perhaps the collapse of agriculture/ensuing drop in aerosols from industrial collapse would be sufficient to spike global temps / cause bluest Arctic event yet / result in ensuing spiral.
I fail to understand where your knowledge of the future comes from. As this is a science forum, crystal balls are not an accepted prediction method. Something is currently happening, more snow has fallen than usual this winter, and more snow has melted. In past winters when more snow fell, more snow has melted as well.
You provide near certainty that more and more snow will fall, citing numbers that are 3x or 4x the current snowfall, and that May melt will not be commensurate with all that snow available to melt. These are extraordinary claims, as both fly in the face of recent trends. Instead of posting some kind of ordinary or extraordinary evidence, you cite your "knowledge". This year you claimed melt rate would be limited, and so the extra snow will have to stay on the ground. Instead we got around 700 km3 in a week, and it's not even May yet. More snow, more melt when warm weather comes. So I think you need some other source of evidence, more scientific, either based on actual data or on rigorous modelling.
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on May 01, 2018, 05:29:54 PM
Is this pic not telling that there is less snow falling ? Or is my interpretation wrong.
Title: Re: Northern Hemisphere snow cover
Post by: magnamentis on May 01, 2018, 06:48:02 PM
Rutgers monthly #s out, show similar to 4/2013.

Interesting to note the Himalayas are also standing out. Perhaps the Canuck purples there aren't imaginary either.

I suspect as we hurtle past solstice, the ongoing Himalayan anomaly will assist in atmospheric heat transport both to the south (ending up in Bering) and to the N (ending up in Siberian Seas).

you already know that i often share your general direction of thinking but then, while perhaps you do it on purpose like some kind of a wakeup call, you usually jump a bit toooo... far and predict events that, even should they really happen which many times i believe like yourself, will happen a looootttt... later than this year or next year.

as you also know i'm someone who votes for the least possible exaggeration to keep a maximum of credibility. what deniers and the greedy jump to is any missed deadline or value, hence we shouldn't feed them without need or without making an "Honest" mistake at least.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on May 01, 2018, 09:19:14 PM
So if you're going to continue with these baseless predictions, maybe you should come up with better arguments. Scientific papers modelling your predictions? Specific locations where this change in melt-out into summer actually occurred? Just repeating your fantastic prediction ad nauseum gets nowhere.

Do you mean like the comment posted by gerontocrat just above yours where studies suggest a long term decline in NH snow?
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on May 01, 2018, 09:26:11 PM
Is this pic not telling that there is less snow falling ? Or is my interpretation wrong.

With 15 of the last 20 years having negative anomalies (from your chart) while 5 have had positive anomalies, this would suggest that April snow cover has been declining.
Title: Re: Northern Hemisphere snow cover
Post by: Archimid on May 01, 2018, 09:45:11 PM
Eurasia is seemingly a bit slower to respond but in North America, after 2018, the trend in April is undeniable, I would say it has now firmly flipped from "warmer" to "colder".

Why do you say colder and warmer when using a snow anomaly chart? It is warmer. The increase in the extent can be attributed to higher temperatures leading to a moister atmosphere that even when warmer, is still below freezing.

As the world warms, the atmosphere will hold even more water but the time spent below freezing get's shorter. I still expect a lot of snow to fall, but it will melt fast, just like it is melting now.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on May 01, 2018, 09:59:22 PM
In the 80's in Chicago, we would frequently have winters where snow would cover the ground for 6 to 8 weeks. This never happens now. Even when we get massive snowfalls, 15 inches or more, it has melted out in a week.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 01, 2018, 10:16:52 PM
Eurasia is seemingly a bit slower to respond but in North America, after 2018, the trend in April is undeniable, I would say it has now firmly flipped from "warmer" to "colder".

Why do you say colder and warmer when using a snow anomaly chart? It is warmer. The increase in the extent can be attributed to higher temperatures leading to a moister atmosphere that even when warmer, is still below freezing.

As the world warms, the atmosphere will hold even more water but the time spent below freezing get's shorter. I still expect a lot of snow to fall, but it will melt fast, just like it is melting now.
It is late, so perhaps the following is written a bit awkwardly.

On the sea ice threads, we talked about ice-free days some time ago. As the years go by each peripheral sea is gradually having more ice-free days as well as a lower maximum. It would seem logical that a similar process is likely to happen with snow.

As the world warms the snow line creeps up the mountain slopes and creeps northwards. Snow, though it may be more intense when it comes through more moisture in the air, comes later and melts earlier or, at the margins, does not come at all.

Thus it is perfectly possible in some years to have greater snowfall and less days with snow on the ground. They are not incompatible. Indeed, one of the papers I referenced said the decline was most marked by the reduction in perennial snow, i.e. snow-free days (days with no ice on the ground) were appearing in places that used to have snow on the ground all year round.

That's me done hypothesising - from now on I am just going to watch it melt.
Title: Re: Northern Hemisphere snow cover
Post by: Grubbegrabben on May 01, 2018, 10:53:58 PM
I know it may sound incorrect, but in fact, impending re-glaciation is WORSE than global warming. Global warming is a distant problem that the public perceives to be irrelevant to current times, while rapidly increasing hemispheric snowfall is a phenomenon happening TODAY

I am beginning to become concerned we may see major crop failures in the Plains and Midwest this year. The forecast for the next 10 days shows snow and cold *worsening* across the northern tier of the US -- it is literally an equivalent to the Day After Tomorrow relative to the Aprils we have seen since the 1800s. This is seriously BEYOND and somehow the only people who know about this seem to be on this forum

Humanity's industrial complexes will fail extremely rapidly as the grain-growing regions of the "First World" are subsumed in snow and ice through May and June

At that point, we sacrifice June to melt as well. There is still probably enough heat to ensure annual melt-out in most regions, but if we get to 9,000-12,000KM^3 of SWE... there may not be. Long before the latter point, harvests in the grain belts will begin failing, perhaps the collapse of agriculture/ensuing drop in aerosols from industrial collapse would be sufficient to spike global temps / cause bluest Arctic event yet / result in ensuing spiral.

The various collapse and doomsday predictions that you keep repeating are a bit boring and may be more appreciated on another forum. If you chose to stick by them please at least try to base them on some sort of facts or evidence and not just fantasies.

The high SWE seems to melt out pretty quickly. Extent is within 1 SD (normal) so I think the grain belt will be safe this year as well. At least the USDA statistics show nothing more than a slight/moderate delay in the planting season. Winter wheat might even have higher yields this year thanks to the extra moisture.

Title: Re: Northern Hemisphere snow cover
Post by: Neven on May 01, 2018, 11:00:40 PM
I'd also like to ask people to pay a bit more attention when quoting other posts, removing everything they're not responding to, and definitely not quoting comments that have quoted other comments that have quoted other comments.

Grubbegraben's comment above this one is a prime example of how it should be done.
Title: Re: Northern Hemisphere snow cover
Post by: Daniel B. on May 02, 2018, 03:24:17 AM
The various collapse and doomsday predictions that you keep repeating are a bit boring and may be more appreciated on another forum. If you chose to stick by them please at least try to base them on some sort of facts or evidence and not just fantasies.

The high SWE seems to melt out pretty quickly. Extent is within 1 SD (normal) so I think the grain belt will be safe this year as well. At least the USDA statistics show nothing more than a slight/moderate delay in the planting season. Winter wheat might even have higher yields this year thanks to the extra moisture.

If I had a dollar for every doomsday prediction that did not materialize ...  Since the number one factor affecting crops is precipitation, this year looks safe.  The second leading factor is temperature, which may be a slight inhibitor if the prolonged cold delayed the planting significantly.  These may cancel each other out, or one may override the other - most likely the extra moisture (as you mentioned).
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on May 02, 2018, 06:19:52 PM
I would like to go on the record as saying that the changes in NH snow cover that we have been seeing recently are interesting and an appropriate topic for this wonderful blog. Based on some of the comments posted here, we are seeing trends to suggest...

1. Positive snow anomalies in the Fall and early Winter
2. Negative snow anomalies in the Spring (this Spring a very notable exception)
3. Record breaking snowfalls in some regions of the NH

...and others that I am sure to be forgetting.

Some questions I have...

Based on early, heavy snowfalls insulating the ground from bitter cold winter temps, could we see a more rapid warming and degradation of permafrost?

What effect does early snow cover have on NH albedo?

Is heavier snow fall occurring over portions of the Arctic Ocean and, if so, could this retard sea ice thickening?

What are the local, regional effects of shifting snow fall patterns?

I would love to see more data that measures the changes that are occurring, more like the various measures, many of them home grown, that track sea ice. One suggested above would be the trend in snow cover free days by region and some analysis of such metrics that might help answer the above questions or cause us to ask new ones.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 02, 2018, 07:27:38 PM

Based on early, heavy snowfalls insulating the ground from bitter cold winter temps, could we see a more rapid warming and degradation of permafrost?

In my opinion - YES.

I did a long post on March 18 about that on the Arctic Methane Release Thread

https://forum.arctic-sea-ice.net/index.php/topic,12.msg146265.html#msg146265

I linked to two articles:-
https://www.sciencedaily.com/releases/2016/03/160302204625.htm
How permafrost thawing affects vegetation, carbon cycle
Study focuses on Toolik Lake area of Alaska's North Slope
Date: March 2, 2016
Source: University of Delaware

http://iopscience.iop.org/article/10.1088/1748-9326/11/9/091004/pdf
In their recent article, Alexeev et al (2016 Environ. Res. Lett. 11 074022) highlight another,
and unexpected, consequence of Arctic sea ice retreat: the thinning of lake ice in northern Alaska. This is attributed to early winter‘ocean effect’snowfall which insulates lake surfaces and inhibits the formation of deep lake ice. Lake ice thinning has important consequences for Arctic lake hydrology, biology and permafrost degradation......

Enjoy (not my theories and I wish they did belong to me)
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on May 02, 2018, 08:28:57 PM
Thank you...nice articles.
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on May 03, 2018, 12:06:08 AM
As mentioned already the Rutgers NH snow cover value for April was 32.06 million km2 which gives a monthly anomaly of +1.84.

All the months of 2018 have had positive anomalies (January only just shaded it).

This April anomaly was the highest since April 2013 and was second highest in a 22 year period stretching back to next highest back in 1996.

If spring 2013 is taken as a good match, well the positive anomalies were not sustained into May of that year (instead there was a -2.74 neg anomaly).

2018 NH monthly anomalies are attached - shown with recent years 2016, 2017 for comparison.   
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on May 03, 2018, 01:40:18 AM
Earlier in this thread I have seen some posts on snow depths from individual stations, so I was wondering how do things stand at some of the high Arctic stations ? Especially areas which have seen a considerable reduction in sea ice ?

Yr.no have nice climate stats and graphs. I just had a look at the stats for Ny-Ålesund (Svalbard). It is located on the northwest coast of Spitzbergen Island. In operation since 1974.

https://www.yr.no/place/Norway/Svalbard/Ny-Ålesund/statistics.html

The west Spitzbergen warm current runs close to the station but since the summer of 2017 ice has been noticeably absent from the north coast of Svalbard.

Svalbard has seen some of the highest positive temperature anomalies of anywhere on the globe. A quick check on the past 12 months May 17 to Apr 18 shows that the mean temperature at Ny-Ålesund was -2.0 C (+4.3 above the normal).

How has precipitation and snow cover there responded to this ?

The monthly precip chart shows a huge peak in Sept 17 (all rain) followed by a dry Nov/Dec period and then a snowy Jan and Feb. For the 12 month period total precip was 531mm versus norm of 385mm (138% of normal).

The snow cover only got going circa the Winter Solstice (5cm lying). It went back down to zero on January 14 & 15 and then peaked at 44cm on Feb 8th. But recent cold/snowy weather has brought lying snow back up to 43cm on Apr 29th. May 1st 2017 it was 27cm.

Last summer all the lying snow was gone by June 6th. (see grey/black bar chart at bottom of second chart for snow depths).
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 09, 2018, 04:04:08 PM
It is interesting to note the cold anomalies are again expected to widen soon. But how long will that last?

Perhaps as the sun moves higher in the sky for the very high Arctic, the greater discrepancy of extant snow vs very weak sea ice acts as an additional thrust to eject the PV into the continents vs. the additional solar gain in the high Ice? The date this happens is around 5/5-10.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018050900/ecmwf_T850_namer_11.png)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 09, 2018, 07:43:17 PM
There is currently a blip in the snow melt - except for N. America snow extent which is glued to the 1 SD line.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 09, 2018, 11:48:53 PM
There is currently a blip in the snow melt - except for N. America snow extent which is glued to the 1 SD line.

I wonder if, as peak insolation reaches/extends further N, the discrepancy "traps" the PV/etc in extant snowcover that remains before that transition occurs? (about 5/5-10 when 90N surpasses 60N), when this happens alongside very weak polar sea ice?

It is interesting how much things have slowed since then. I think if we had another 500-1,000KM^3 going into mid-April, you can see how that would result in major changes wayyyyy past 5/1, especially as the proportion of the cryosphere composed of SWE instead of polar sea ice continues to rise each year.


(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018050912/ecmwf_T850a_nhem_11.png)
Title: Re: Northern Hemisphere snow cover
Post by: oren on May 10, 2018, 02:58:04 AM
Last North American mini-maximum now either underway or likely within a day IMO... we are officially +100% or 2X normal SWE for the date (1,550 KM^3 vs. approx 775 KM^3).

April SWE has so far increased by about 50 KM^3... this has widened the discrepancy from about 500 KM^3 vs. avg as of 3/31. I.E. the departure vs. normal has increased by 55% over the past three-ish weeks.

Rolling forward, if the same departure "schedule" is maintained, it will still result in impending losses. But it would indicate we are probably going to be at or over 1,250KM^3 as of 5/1 (150% of normal). And if gains vs. normal remain steady through May, we will still have approximately 750-800KM^3 of SWE remaining as of 6/1 (vs. 225KM^3 or so normally).

If we are not at or near 1,250KM^3 by 5/1, these estimates will need upward revisions (IMO).

In any case, the dynamic of snow melt this year is going to be far more important far deeper into the season than is normally the case. I do not think May will resolve the anomaly, it is IMO going to take at least the addition of June, and possibly even the entirety of July. It will still be resolved, but the implications for sea ice melt and sensible weather over North America are likely to result in summer extremes that have not been seen in Industrialized History.

This leads me to make one bold prediction: June will be the coldest on record across the upper Midwest and Northeast US. It will also mark the start of a substantial slowdown in the Gulf Stream, a la 2009, but worse. Perhaps I will be wrong, but this should be verifiable! :)
bbr I took the liberty of quoting a post you made 3 weeks ago. Bold markings are mine.
Instead of the predicted 1250 km3, April ended with 800 km3. It didn't take neither May nor June nor July to resolve the anomaly, April was enough to bring it almost to the 1 SD line. You are severely underestimating the ability of snow to melt once warm weather arrives.
So when you say:
It is interesting how much things have slowed since then. I think if we had another 500-1,000KM^3 going into mid-April, you can see how that would result in major changes wayyyyy past 5/1, especially as the proportion of the cryosphere composed of SWE instead of polar sea ice continues to rise each year.
I believe you are wrong as well, and I wish you would avoid making such wild predictions/what ifs not based on actual data.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 10, 2018, 03:18:21 AM
Last North American mini-maximum now either underway or likely within a day IMO... we are officially +100% or 2X normal SWE for the date (1,550 KM^3 vs. approx 775 KM^3).

April SWE has so far increased by about 50 KM^3... this has widened the discrepancy from about 500 KM^3 vs. avg as of 3/31. I.E. the departure vs. normal has increased by 55% over the past three-ish weeks.

Rolling forward, if the same departure "schedule" is maintained, it will still result in impending losses. But it would indicate we are probably going to be at or over 1,250KM^3 as of 5/1 (150% of normal). And if gains vs. normal remain steady through May, we will still have approximately 750-800KM^3 of SWE remaining as of 6/1 (vs. 225KM^3 or so normally).

If we are not at or near 1,250KM^3 by 5/1, these estimates will need upward revisions (IMO).

In any case, the dynamic of snow melt this year is going to be far more important far deeper into the season than is normally the case. I do not think May will resolve the anomaly, it is IMO going to take at least the addition of June, and possibly even the entirety of July. It will still be resolved, but the implications for sea ice melt and sensible weather over North America are likely to result in summer extremes that have not been seen in Industrialized History.

This leads me to make one bold prediction: June will be the coldest on record across the upper Midwest and Northeast US. It will also mark the start of a substantial slowdown in the Gulf Stream, a la 2009, but worse. Perhaps I will be wrong, but this should be verifiable! :)
bbr I took the liberty of quoting a post you made 3 weeks ago. Bold markings are mine.
Instead of the predicted 1250 km3, April ended with 800 km3. It didn't take neither May nor June nor July to resolve the anomaly, April was enough to bring it almost to the 1 SD line. You are severely underestimating the ability of snow to melt once warm weather arrives.
So when you say:
It is interesting how much things have slowed since then. I think if we had another 500-1,000KM^3 going into mid-April, you can see how that would result in major changes wayyyyy past 5/1, especially as the proportion of the cryosphere composed of SWE instead of polar sea ice continues to rise each year.
I believe you are wrong as well, and I wish you would avoid making such wild predictions/what ifs not based on actual data.
My reasoning is the same as people's support behind an impending BOE... an extrapolation of recent trends... ???

The % of the crysophere held in SWE instead of sea ice nearly doubled in the last 15 yrs as of 4/15...
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 10, 2018, 12:24:33 PM

The % of the crysophere held in SWE instead of sea ice nearly doubled in the last 15 yrs as of 4/15...
One very last thought on this subject.

Cherry picking one day from an unusual year for snowfall.

Arctic Ice Volume in April has dropped by 300 km3 per annum on average since 1979, and was just above 22,000 km3 in April 2018.

Even if SWE does not increase from the average April max of about 3,250 km3, the ratio of SWE to Sea Ice Volume will increase, reaching about 18% (assuming sea ice loss continues at about 300 km3 per annum).

Because the SWE this year in April was so high, that ratio was 19%.

Should SWE increase by, say, 1.5% cumulative per annum from that unusual high max SWE of about 4,250 km3, by 2030 the ratio would be about 29%.

But - so what? That increased snowfall presumably must come from higher temperatures causing increased moisture at high latitudes. But higher temperatures mean increased melt. So what would the net effect be on extent ?
Shorter snow seasons at lower latitudes leading to early melt and lower albedo - positive feedback?
Increased snow at higher latitudes leading to a later melt and higher albedo - negative feedback ?

Without data and at least some arithmetical predictions on SWE and extent (which you have not provided), debate is fruitless.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on May 10, 2018, 04:22:44 PM
And what we end up with is hypothetical speculation of the long term impact of what appears to be a trend of increased snowfall which is what I would expect from a warming planet. More moisture in the atmosphere combined with intrusions of cold air into the mid latitudes due to the more frequent collapse of the PV results in heavier snowfalls.

Lived in Chicago all of my life and we have had some amazingly heavy snowfall events over the past 5 years. In the 1980's, this snow would have been on the ground for the entire winter. We now have 18 inch snowfalls melt in a week in the dead of winter and bare ground through most of the winter is the rule.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 10, 2018, 06:43:18 PM

The % of the crysophere held in SWE instead of sea ice nearly doubled in the last 15 yrs as of 4/15...
One very last thought on this subject.

Cherry picking one day from an unusual year for snowfall.

Arctic Ice Volume in April has dropped by 300 km3 per annum on average since 1979, and was just above 22,000 km3 in April 2018.

Even if SWE does not increase from the average April max of about 3,250 km3, the ratio of SWE to Sea Ice Volume will increase, reaching about 18% (assuming sea ice loss continues at about 300 km3 per annum).

Because the SWE this year in April was so high, that ratio was 19%.

Should SWE increase by, say, 1.5% cumulative per annum from that unusual high max SWE of about 4,250 km3, by 2030 the ratio would be about 29%.

But - so what? That increased snowfall presumably must come from higher temperatures causing increased moisture at high latitudes. But higher temperatures mean increased melt. So what would the net effect be on extent ?
Shorter snow seasons at lower latitudes leading to early melt and lower albedo - positive feedback?
Increased snow at higher latitudes leading to a later melt and higher albedo - negative feedback ?

Without data and at least some arithmetical predictions on SWE and extent (which you have not provided), debate is fruitless.

I gave you my arithmetic.

Since 2000 we have seen the total volume of 29,200 drop to 26,600.

We have seen the proportion of SWE since then rise, as of mid-April, from 7.5% to 13.5% (2,200 -> 3,600 KM^3).

By the early 2030s I think there will be a year with ~6,000KM^3 by 4/15, or about 24% of mid-April Cryospheric volume. At that time, April sea ice will have a volume of ~17,000KM^3.

The implications of this April's event are currently manifesting in projected enduring cold anomalies across Siberia and much of northern Canada. These albedo-driven fortresses of cold have now become the primary reservoir outside of Greenland in the Northern Hemisphere as solar forcing over the High Arctic / porous and mostly first year sea ice is producing lower albedoes than the continually-refreshed snowfalls over the high Tundra (post 5/5-10).

It will be interesting to see if this persists until mid-July when the brunt of solar again falls on the Tundra. But I think this is another interesting thing to consider as we move into the future. As the brunt of solar insolation shifts from Tundra to High Arctic on an annual basis, do residual albedo anomalies in southern areas retain a "boost" in their staying potential, when the high Arctic is a porous and heat-sopping mess?

The projected pattern would seem to argue that as our situation worsens, random weird variations like ^ begin to occur.

(https://www.tropicaltidbits.com/analysis/models/gem/2018051012/gem_z500_mslp_nhem_16.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018051000/ecmwf_z500_mslp_nhem_7.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 11, 2018, 10:04:23 PM
Quebec!

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018051112/ecmwf_T850_namer_6.png)

Quebec! :D

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018051112/ecmwf_T850_namer_11.png)
Title: Re: Northern Hemisphere snow cover
Post by: TerryM on May 11, 2018, 11:05:12 PM
, and a whole bunch of Labrador :)
Terry
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 13, 2018, 01:11:34 PM
Data as at 12 May from https://www.ccin.ca/ccw/snow/current

Northern hemisphere Snow Water Equivalent (mass) is 2,000 km3 (GT), about double the average for this date.
Despite this, Snow Cover Extent is only a maximum of one week behind the average schedule. 
Title: Re: Northern Hemisphere snow cover
Post by: Neven on May 13, 2018, 01:18:14 PM
Good to see that the purple snow on the Tibetan Plateau is still holding out. How many years has it been now?  ;)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 13, 2018, 04:23:09 PM
Good to see that the purple snow on the Tibetan Plateau is still holding out. How many years has it been now?  ;)
The purples actually went away substantially over the winter, and are only now emerging in force once more... I swear!!!
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 13, 2018, 11:05:24 PM
Model output 28 days from solstice is..... STILL COLD

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018051312/ecmwf_T850_namer_11.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 19, 2018, 09:52:51 PM
6/1 approaches... solstice 23 days from 5/28... yet the cold remains across Quebec!

Perhaps it will take the second annual insolation spike in mid/late July to fully melt the rest out.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018051912/ecmwf_T850a_nhem_11.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018051912/ecmwf_T850_namer_11.png)

And perhaps Hudson Bay will retain substantial ice coverage into mid or late August? I think early August is all but guaranteed. This could also artificially inflate total sea ice #s later into summer vs normal.

SWE is now roughly double vs. normal once more, extent also high, but SWE is what's making a huge difference ATM RE: albedo as high Quebec/NWT are still *exceedingly* white looking at satellite imagery, with the only recent comparison being 2009 (IMO). HB is also still very snow-covered vs. normal.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)

I like 2009 as an analog / perhaps firms the chances of a moderate-strong Nino as we head into fall and 2019.
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on May 19, 2018, 11:42:17 PM
On ventusky they have 32 degree C on the edges of Hudson Bay in a few days. And a couple days later a big part of the ice is gone.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 23, 2018, 06:02:36 PM
Data as at 22 May from https://www.ccin.ca/ccw/snow/current

The persistent cold in the NE of Canada continues to have a significant effect on the snow melt.
Eurasia - while behind the average schedule is losing both extent and mass quickly.

I think the 1st of June would be a good time to have another look.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 27, 2018, 01:07:00 PM
Data as at 26 May from https://www.ccin.ca/ccw/snow/current

The persistent cold in the NE of Canada (Quebec & Terre-Neuve et Labrador) continues to have a significant effect on the snow melt extent. Now Snow Water Equivalent (i.e. mass/thickness) reduction has also slowed - the anomaly especially high in the Canadian Archipelago and Northern Quebec.

While Eurasia is behind the average schedule it is losing both extent and mass quickly.

GFS 3 and 5 day forecasts strongly suggest that by the end of the month there will be a lot of warming going on in parts of the high latitudes of N. America.

I think the 1st of June would be a good time to have another look.
Title: Re: Northern Hemisphere snow cover
Post by: Daniel B. on May 27, 2018, 03:32:38 PM
Not to mention the recent snowfall as far as southern Newfoundland.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on May 28, 2018, 05:32:50 PM
Looks like more snow impending for Newfoundland...

(https://www.tropicaltidbits.com/analysis/models/gem/2018052800/gem_asnow_namer_40.png)
Title: Re: Northern Hemisphere snow cover
Post by: Brigantine on May 28, 2018, 10:54:27 PM
Not only a forecast a whole 10 days out, but a total over the full 10 days.

Presumably safe to ignore, unfortunately. Do you have a 5-day version of that instead?

If a 5-day version showed something similar, it would be very interesting, especially over the CAB.
(though still not necessarily different from previous years?)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on May 28, 2018, 11:37:19 PM
Not only a forecast a whole 10 days out, but a total over the full 10 days.

Presumably safe to ignore, unfortunately. Do you have a 5-day version of that instead?

If a 5-day version showed something similar, it would be very interesting, especially over the CAB.
(though still not necessarily different from previous years?)
The image from bbr2314 shows, I believe, total accumulated snowfall forecast over the next 10 days. How much will have melted along the way is another story.

Some of the time Newfoundland will be cold and snowy - and some of the time Newfoundland will be warm and the snow will melt. It is that time of year.
Title: Re: Northern Hemisphere snow cover
Post by: Sleepy on May 29, 2018, 06:00:59 AM
End of season.
On May 17, 2018, none of SMHI's observation stations had a measurable snow depth. It is therefore no longer meaningful to update the snow depth map for the 2017-2018 season. However, note that there is still snow in higher mountain ranges, but SMHI does not measure snow depth there.
https://www.smhi.se/vadret/vadret-i-sverige/snodjup (https://www.smhi.se/vadret/vadret-i-sverige/snodjup)

Also adding temperature anomalies for May 1-28.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 02, 2018, 09:49:24 PM
June snows in New England are extraordinarily rare, the best known case is 1816. Coincidental to talk of developing Nino, snow showers did occur 6/1/2009.

(https://www.tropicaltidbits.com/analysis/models/gem/2018060212/gem_asnow_us_36.png)
Title: Re: Northern Hemisphere snow cover
Post by: Brigantine on June 03, 2018, 06:07:00 AM
The first data point from June

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fglobalcryospherewatch.org%2Fstate_of_cryo%2Fsnow%2Ffmi_swe_tracker.jpg&hash=7d01448218c9fe1555d12dad667406c0)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on June 03, 2018, 11:19:46 AM
The first data point from June

And from the same site extent map of N. America June 2. (https://www.ccin.ca/ccw/snow/current)

So why have they not updated the SWE and extent graphs since May 28? Annoying or what.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 03, 2018, 06:00:07 PM
The first data point from June

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fglobalcryospherewatch.org%2Fstate_of_cryo%2Fsnow%2Ffmi_swe_tracker.jpg&hash=7d01448218c9fe1555d12dad667406c0)
WOOF! 2X normal *without* mountain SWE!

CCIN is annoying but it is obvious looking at satellite we are still way above normal.

I think this verifies the notion that extreme spring SWE can result in a lag to the melt season (and/or its lengthening). This results in increasingly negative temperature anomalies as you head deeper into spring (and then summer), as the proportion vs normal becomes vastly more impactful when normal hits or approaches 0 and a sizable extant volume remains. I think this also results in extremely insane weather patterns as the extant albedo combines with the abysmal sea ice conditions (i.e. relatively poor-er albedo vs. norm) to generate a "flipped" 500MB pattern where blocking / continental warmth increasingly dumps into the Arctic.

I think the most surprising development this year after the gains themselves were 1) the extremely steep and rapid April NA SWE loss and 2) the extreme and prolonged plateau thereafter, which seemingly continues to-date.

Given the combination of the two factors ^, I think we are vastly under-estimating the impact of increased NHEM snowfall and its potential to mitigate absolute global warming (but aggravate net effect / damage of climate change). It is now seemingly plausible that a 1,000KM^3 melt event can help maintain limited but severe continental cooling in the weeks thereafter, constrained to the geography of the snowcover that remains as peak solar transitions toward the High Arctic.

The question is, if we have another 500KM^3 extra SWE at peak-April in another five years, does the proportion of that extra SWE that is going to melt by June *decrease* as the overall surplus increases?

As we move forward into the 2020s, if ^ is accurate, I except April and May to become increasingly wintry across parts of Eurasia/Europe and North America. June is also likely to follow for the populated belt of 40-50N by the end of the decade, if the trends re: sea ice and SWE are continued.

If we repeat 2003-2018, 2033 will have about 2,000-2,500KM^3 extra accumulated continental SWE by mid April, and North America specifically will be about double its current #s, at 3,200KM^3 vs. 1,600KM^3 seen this year.

If *doubling* early 2000s normals in Mid-April (2018) is sufficient to result in our current situation by June, quadrupling them is going to result in anomalies persisting into at least July and possibly August. Summer snow may soon become a normal event in cities like Montreal.

(https://ccin.ca/home/sites/default/files/snow/snow_tracker/na_swe.png)
Title: Re: Northern Hemisphere snow cover
Post by: oren on June 03, 2018, 08:22:02 PM
As usual, I wish to counter these statements. Statistics of snow depth don't show that thick winter snow lasts much longer than thinner snow. Melt-out date mostly depends on weather suitable for melting, and on additional spring snows. I believe this statistical evidence shows that snow does not create its own weather, even if this year happens to combine thick winter snow with delayed melt-out.
Moreover, albedo is set by snow extent, not depth, and extent this year is not extreme, running at slightly above +1SD. Not a weather-shattering figure.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 03, 2018, 08:39:02 PM
As usual, I wish to counter these statements. Statistics of snow depth don't show that thick winter snow lasts much longer than thinner snow. Melt-out date mostly depends on weather suitable for melting, and on additional spring snows. I believe this statistical evidence shows that snow does not create its own weather, even if this year happens to combine thick winter snow with delayed melt-out.
Moreover, albedo is set by snow extent, not depth, and extent this year is not extreme, running at slightly above +1SD. Not a weather-shattering figure.
That is incorrect. Albedo is highly affected by depth. Compare satellite of this year versus all since 2000. 2009 is the only year that comes close to the brightness of 2018.

Depth is especially significant over Tundra. The difference between 5" and 10" of snow is coverage of all vegetation and complete whitness / near perfect albedo (e.g., just look at satellite data this year). Depth is critical to albedo -- the deeper the snowpack, the brighter it typically appears on satellite.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on June 04, 2018, 12:47:18 AM
Albedo is highly affected by depth.

This is not true.

https://www.climate-policy-watcher.org/snow/snow-albedo.html

Freshly fallen snow has the highest albedo. Slight surface melt of deep snow can lower albedo dramatically due to changes in snow crystals.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 04, 2018, 02:45:07 AM
Albedo is highly affected by depth.

This is not true.

https://www.climate-policy-watcher.org/snow/snow-albedo.html

Freshly fallen snow has the highest albedo. Slight surface melt of deep snow can lower albedo dramatically due to changes in snow crystals.
??? That does not dispute ^. Yes, deep snow can get blue-er. But 10" of snow has a higher albedo impact vs. 2" of snow.
Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on June 04, 2018, 06:04:49 AM
Quote
... There is no evident increase in the mean of surface albedo after it reaches 0.7 (0.6) in the dry (wet) snow season, corresponding to a snow depth of around 20 cm (30 cm). ...
An observational study of snow aging and the seasonal variation of snow albedo by using data from Col de Porte, France (https://www.researchgate.net/publication/267761663_An_observational_study_of_snow_aging_and_the_seasonal_variation_of_snow_albedo_by_using_data_from_Col_de_Porte_France?_sg=n70kRVkIyj-dG306R-LsZs8cXUIL2DfSegSVafXdja-3j89C6L3vRTvydkGR7DuUDPguXzjXoQ)

So, it appears albedo is affected by depth for snow when the depth is less that 20 or 30 cm (8-12"), according to this paper.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 04, 2018, 06:32:51 AM
Indeed! If this is accurate it is extremely alarming as the yawning + SWE gap means a vastly higher % of area is going to pass the threshold where albedo impacts are much greater, for a much longer % of the year.

I wonder how close we are to a runaway effect, given the lag in SWE loss this May. It may only take a doubling relative to current values for albedo/etc to allow snowcover to begin piling up year-round in places like Quebec, and current forecasts showing snow falling as we are almost at solstice would support the notion that, if SWE was even doubled, many regions could make it through solstice at which point they would only have to survive the relative heat surge from the declining high sun in late July, before "autumn" kicks in by August.

I would also expect the curves for Tundra relative to a mountain valley in France are more gradual / have higher end-results. EOSDIS shows Nunavut and Northern Quebec on par with Greenland, or even brighter.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 04, 2018, 09:09:48 AM
Tonight's 00z EURO is quite impressive, reverting again to sustained cold across Quebec through D10. Wow!

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018060400/ecmwf_T850a_namer_11.png)

Seven days from solstice... incredible!

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018060400/ecmwf_T850_namer_11.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 05, 2018, 01:45:53 AM
SWE-albedo feedback verified IMO:

http://nunatsiaq.com/stories/article/65674cold_spring_breaks_records_in_nunavik_nunavut/
Title: Re: Northern Hemisphere snow cover
Post by: oren on June 05, 2018, 02:38:27 AM
SWE-albedo feedback verified IMO:
How is this proof of a feedback mechanism, rather than merely a late spring in some of the locations?
In order for there to be a SWE-albedo feedback mechanism, there needs to be a statistical predictive power - areas with high anomalous snow at a certain date (say April) should show a tendency for anomalously cold weather at a certain later date (May). This predictive power should be verifiable over different years.
Merely showing that spring arrived late in some locations in May coinciding with late snow cover in the same locations in May means nothing. A late spring will lead to a late snow cover.
In addition, there should be some relation between the specific locations of high SWE in April, and the temperatures in May. Not just that high NA SWE in general resulted in some locations having a late spring (while others had an early spring).
This year, anomalously high snow was prevalent south of Hudson Bay and across Quebec, while late spring happened mostly north of Hudson Bay, and in northern Quebec. Ontario had high April snow but positive anomaly temps in May. My tired old eyes can't see the proposed correlation this year (not to mention that we need similar data from other years in order for this to be serious proof).
(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=103.0;attach=99562;image)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fnunatsiaq.com%2Fpub%2Fphotos%2Fmap_may2.jpg&hash=a9aa96dc0ca7a462188d41c4b5c1c123)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 05, 2018, 02:44:03 AM
SWE-albedo feedback verified IMO:
How is this proof of a feedback mechanism, rather than merely a late spring in some of the locations?
In order for there to be a SWE-albedo feedback mechanism, there needs to be a statistical predictive power - areas with high anomalous snow at a certain date (say April) should show a tendency for anomalously cold weather at a certain later date (May). This predictive power should be verifiable over different years.
Merely showing that spring arrived late in some locations in May coinciding with late snow cover in the same locations in May means nothing. A late spring will lead to a late snow cover.
In addition, there should be some relation between the specific locations of high SWE in April, and the temperatures in May. Not just that high NA SWE in general resulted in some locations having a late spring (while others had an early spring).
This year, anomalously high snow was prevalent south of Hudson Bay and across Quebec, while late spring happened mostly north of Hudson Bay, and in northern Quebec. Ontario had high April snow but positive anomaly temps in May. My tired old eyes can't see the proposed correlation this year (not to mention that we need similar data from other years in order for this to be serious proof).
(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=103.0;attach=99562;image)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fnunatsiaq.com%2Fpub%2Fphotos%2Fmap_may2.jpg&hash=a9aa96dc0ca7a462188d41c4b5c1c123)

Spring was delayed everywhere it just varied depending on the latitude (including Ontario). If you can't see the correlation between the SWE map and the attached to this post I can't help you. I do agree we need more years of data for verification but to me this feels like a 2007 or 2012-esque state change that will soon begin accelerating too quickly for meaningful data to accumulate before impacts begin to extend much deeper into the spring and summer.

I would even posit ^ is already happening as the +extent still remaining (and high albedoes) are acting against a horribly melted High Arctic to fire continental heat pulses directly toward the CAB from both Eurasia and North America.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 05, 2018, 02:49:39 AM
I would like to add a prediction as well. The maps ^ show that the entire High Arctic has been torching with the exception of HB, BB, and Kara.

Each of these regions are likely (IMO) to retain substantial area well into August, and final melt-out will not occur entirely until 8/15-9/1.

This is going to create a situation where the ridiculous 500MB anomalies already presenting continue to worsen as the residual extent/SWE situation in adjacent landmasses combine with the "protected" ice this season to prolong the springtime pattern well into summer.

This also means that area/extent numbers in the High Arctic (focused on CAB) may well reach their lowest levels on record, as cold air is unable to resolve/remain in the Arctic Ocean and is instead focused in the vortexes SW of Greenland and over the Kara (and eventually there will be another in NE Siberia).
Title: Re: Northern Hemisphere snow cover
Post by: oren on June 05, 2018, 03:20:48 AM
I would like to add a prediction as well. The maps ^ show that the entire High Arctic has been torching with the exception of HB, BB, and Kara.

Each of these regions are likely (IMO) to retain substantial area well into August, and final melt-out will not occur entirely until 8/15-9/1.
Interesting prediction, especially as these regions are not anomalous at the moment - HB average, Baffin low, Kara high.
All three regions tend to melt mostly in June and July, with a residue of 50k-100k for HB, 50k-150k for Baffin, and 50k-150+k for Kara on Aug 1st, eyeballing AMSR2 data from recent years. I assume you mean that area retained will be higher than these normal residues. If this comes to pass, and area on Aug 1st is 100k higher than the upper end of the ranges I mentioned, I will be extremely surprised. My own prediction is for normal area residues on Aug 1st.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 05, 2018, 06:31:41 AM
13 days to solstice.!

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fweatheroffice.ec.gc.ca%2Fdata%2Fanalysis%2F352_50.gif&hash=27a5acc641d59a740087f25d02e9a350)

Also: uptick or error? We shall see.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fglobalcryospherewatch.org%2Fstate_of_cryo%2Fsnow%2Ffmi_swe_tracker.jpg&hash=7d01448218c9fe1555d12dad667406c0)
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on June 06, 2018, 08:19:42 AM
Most of you know that I am using Northern Hemisphere snow cover in spring and summer as a predictor for the September minimum. Here is a guest post on ASIB of my method :
http://neven1.typepad.com/blog/2013/07/problematic-predictions-2.html

This method of prediction works really well for June data, but even for May data it has some skill.

Now that Rutgers Snow lab published the Northern Hemisphere snow cover for May (see attached picture), I ran my regression formula on the 1992-2015 training period, using May data for snow cover, ice concentration and ice area, and arrived at a prediction for September sea ice extent minimum of 4.84 M km2.

This number makes sense, since snow cover in May was still fairly high (compared to the previous 10 years), and even though sea ice extent in May was at a record low, sea ice area is actually just 3rd or 4rth lowest. This means the ice pack is still fairly 'compact' which reduces the amount of heat the ice pack will absorb from the ever higher sun in the Arctic.

Standard deviation over the prediction is 460 k km2, which is substantially better than a linear decline as a predictor (which has a standard deviation of about 550 k km2).

So the method has some skill with May data, but for an accurate prediction, please wait for the start of July, when the June data is in, since that has real skill with about 300 k km2 standard deviation.

Until then, the prediction of 4.84 M km2 stands.

[edit] I will submit my prediction to the SIPN this year again :
https://www.arcus.org/sipn
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on June 06, 2018, 04:14:00 PM
It's a negative anomaly for May. NH snow extent stood at 18.26 million km2 which is -0.76 million km2.

This is the first negative anomaly since Dec 2017. Although as Rob's chart shows the negative departure is still a lot less than the May departures we have seen over the last 10 years (2017 excepting).

Cover was below normal over central Siberia and much of western Canada, as the interiors of the continents heated up rapidly. Much of Quebec and western Siberia saw above normal snow cover.

Chart below shows monthly departures over period 2016-2018. 
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 07, 2018, 12:41:58 AM
(https://scontent-iad3-1.xx.fbcdn.net/v/t1.0-9/34506066_10216021475199481_5264471157079277568_o.jpg?_nc_cat=0&oh=a64488cd8ff138a67210f2f6fe060b49&oe=5BBC23A8)
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on June 07, 2018, 01:48:11 AM
I ran my regression formula on the 1992-2015 training period, using May data for snow cover, ice concentration and ice area, and arrived at a prediction for September sea ice extent minimum of 4.84 M km2.

Have you changed your model to fit the new monthly extent calculations from NSIDC? Due to the change the average extent is 100-200k km2 lower than with the old version. I just finished my forecast and got 4.2 million km2.

more details about the monthly sea ice extent change:
https://nsidc.org/sites/nsidc.org/files/files/NSIDC-special-report-19.pdf
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on June 07, 2018, 04:02:58 AM
I ran my regression formula on the 1992-2015 training period, using May data for snow cover, ice concentration and ice area, and arrived at a prediction for September sea ice extent minimum of 4.84 M km2.

Have you changed your model to fit the new monthly extent calculations from NSIDC? Due to the change the average extent is 100-200k km2 lower than with the old version. I just finished my forecast and got 4.2 million km2.

Thank you Tealight. I was not aware of this new definition of Sea Ice Extent.
From the document :
Quote
Monthly averages of numerical ice concentration data can be calculated through two
different methods: 1) summing ice concentration data at each grid cell throughout a
month, dividing by the number of days within a particular month to get average
concentration for that grid cell, and then applying the 15 percent concentration
threshold to the gridded field of average ice concentrations before deriving monthly
area and extent, or 2) applying the 15 percent concentration threshold to the daily
gridded field of concentration data before deriving that day’s area and extent; and then
simply averaging those daily values over the course of the month. The former method is
the basis for the numerical algorithm in V2, while the latter describes V3.

I do think the V3 definition makes a lot more sense, and IIRC we had discussions here on the ASIF and the ASIB about the odd old (V2) definition last year and before.

As far as predictions are concerned, I will enter all new V3 data, and re-do my calculations.

Yet, since the difference is a maximum of 200 k km2, it does not explain the difference between your ("4.2") and my ("4.8") prediction.

How are you accounting for land snow cover in your prediction ?
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on June 07, 2018, 12:10:05 PM
Yet, since the difference is a maximum of 200 k km2, it does not explain the difference between your ("4.2") and my ("4.8") prediction.

How are you accounting for land snow cover in your prediction ?

Land snow cover isn't bad this year. In my model it only becomes a melting factor when it is below 18 million km2. (historically 12-26 May)
It took some experimenting to find this value. I just got the best results with it in reanalysis. If you look at a map and wind systems like nullschool then you can see snow cover values in April don't matter for the Arctic. All the cold air in snowy eastern Canada just gets blown into the mid latitude Atlantic and never effects the sea ice. The same is true for south and eastern Eurasia.

Some Pseudocode:

if snow > 18 million km2:
   additional warming = 0
else:
   additional warming = (18 million km2 - current snow cover)*daily energy on land*energy transfer coefficient


other contributors to my lower prediction:
2nd lowest volume (after 2017)
2nd warmest year for 80N (after 2016)

Edit: after adding a small bias for continuation of this years high compaction ratio I get 4.3 million km2
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on June 08, 2018, 05:13:19 AM
I re-ran my regressions with the new NSIDC V3 data, and indeed ended up a bit lower : 4.65 M km2 Sept extent.
 
Standard deviation over the residuals is a bit higher (470 k km2) than with V2 data, but not substantially.

You are using more variables than me, and use them in a different way (like your snowcover cut-off) so it is not surprising you get a (slightly) different result.

Will you be submitting to SIPN again this year ?
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on June 09, 2018, 10:50:46 AM
Well of course I use variables different then you otherwise it makes no sense to submit it as a different forecast. I already submitted mine and this time chose statistical instead mixed. With the new NSIDC V3 I don't have to guess anymore how much the ice moves in September which increases it's apparent size.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on June 10, 2018, 09:31:03 AM
I have sent an e-mail to Envionment Canada to ask why the snow-tracker graphs on https://www.ccin.ca/ccw/snow/current have not been updated since 28th May.

Maybe they will reply.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 10, 2018, 03:33:53 PM
I have sent an e-mail to Envionment Canada to ask why the snow-tracker graphs on https://www.ccin.ca/ccw/snow/current have not been updated since 28th May.

Maybe they will reply.
If they do not answer I will have to write a letter to DJT and we will have to invade. Restore the snow graphs -- or else!!!
Title: Re: Northern Hemisphere snow cover
Post by: Neven on June 10, 2018, 10:27:12 PM
I have mailed them multiple times a couple of months ago, using various mail addresses, and even tried to call them. But never received a reply.
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on June 11, 2018, 08:09:12 AM
Their stereographic daily projection still seems to be up-to-date :

(https://www.star.nesdis.noaa.gov/smcd/emb/snow/GIF/comb_recent.png)

Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on June 11, 2018, 08:17:14 AM
Their stereographic daily projection still seems to be up-to-date :

Which makes not updating the graphs even more annoying / perplexing.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 11, 2018, 11:31:25 PM
I would think this is further verification that we may be in very deep trouble. It is snowing atop Mauna Kea & Mauna Loa (... 10 days from solstice).

https://www.express.co.uk/news/world/971913/Hawaii-volcano-eruption-freezing-rain-Kilauea

The method is different (lava entering the ocean generating steam which is then rising and cooling the summits). But the way the Arctic behaves will be quite similar as oceanic SSTs continue rising while continental SSTs remain the same / are cooled by Greenland. The combination of continental resilience to heat accumulation via GHGs and oceanic vulnerability = more "steam" (aka clouds), and therefore more snow, as 2018 has proven.

The above is, perhaps, a meaningless anecdote. Or not!
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on June 12, 2018, 01:13:58 PM
ENVIRONMENT CANADA WEBSITE - Lack of Updates

I have mailed them multiple times a couple of months ago, using various mail addresses, and even tried to call them. But never received a reply.

No reply - so I dragged out from a rusty corner in my brain "how to write to the top person.", and wrote an e-mail in posh letter format to "Her Excellency Mrs. Janice Charette,
High Commissioner for Canada to the United Kingdom of Great Britain and Northern Ireland."

I have had an autoreply:-
"Thank you for contacting Public Affairs at the Canadian High Commission in London. We will aim to answer your query as soon as possible."

You never know - it might touch a nerve.





Title: Re: Northern Hemisphere snow cover
Post by: oren on June 12, 2018, 02:18:33 PM
Grntc you are amazing   :D
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on June 12, 2018, 05:35:42 PM
Grntc you are amazing   :D

Yes I am, and totally stunned:- Read on

Quote

Ellsworth LeDrew <ells@uwaterloo.ca>
16:28 (3 minutes ago)
to me, pdc
Good morning
Thankyou for bringing this to our attention.  We are looking into this and will get back with an answer when we are certain of the issue.
Regards.
Ells

Dr Ellsworth LeDrew, F.IEEE, F.CASI,
University Professor,


https://uwaterloo.ca/geography-environmental-management/people-profiles/ellsworth-ledrew

Department of Geography and Environmental Management
University of Waterloo,
200 University Ave West
Waterloo, ON, Canada, N2L 3G1

Phone: 519 888 4567 X32783
FAX: 519 746 0658

ells@uwaterloo.ca
University of Waterloo:  the spirit of “why not?”
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 15, 2018, 09:28:05 PM
If 2018's anomalies can yield a map like this come post-solstice June weather, I would hate to see what these maps look like if we go 25-50%+ beyond the SWE accums of this winter.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018061512/ecmwf_T850_namer_11.png)
Title: Re: Northern Hemisphere snow cover
Post by: Brigantine on June 22, 2018, 01:17:09 AM
It's the solstice. These (http://old.wetterzentrale.de/pics/Rnhemsnow.gif) three (http://cci-reanalyzer.org/wx/DailySummary/#snowd-mslp) datasets (http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow_alaska.gif) (or 4 (https://www.ccin.ca/home/sites/default/files/snow/snow_tracker/plot_anom_sdep.png), or 5 (https://www.star.nesdis.noaa.gov/smcd/emb/snow/GIF/comb_recent.png)) have different ideas about where there is still snow
(actually the last 3 somewhat agree - mainly looking at Victoria Island, Baffin Island and northern Quebec & Labrador).

None of the graphs had updated in 2-3 weeks, but now they're back (https://www.ccin.ca/index.php/ccw/snow/current)! (except for FMI) - Snow water equivalent is back down to ~+1.5SD (another cliff in June). Extent now a bit more than that - ~+2.5SD.
Title: Re: Northern Hemisphere snow cover
Post by: Archimid on June 22, 2018, 04:00:17 AM
Quote
If 2018's anomalies can yield a map like this come post-solstice June weather, I would hate to see what these maps look like if we go 25-50%+ beyond the SWE accums of this winter

In an el Niño year the flood maps would be much more interesting.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on June 22, 2018, 11:30:42 AM
If 2018's anomalies can yield a map like this come post-solstice June weather, I would hate to see what these maps look like if we go 25-50%+ beyond the SWE accums of this winter.

OK, so colder than normal, but GFS says well above freezing most of the time so snow cover extent and SWE will continue to decline. Hudson Sea ice loss is late compared with recent years, but still still ahead of the 1980's, 1990's and 30 year averages. That late snow melt had an effect, but not huge.

Although the literature does seem to say that snowfall in high latitudes will increase, I am still looking for a reason to assume that the 2017-18 very high values are the new baseline for those increases, especially if there is less snow and more rain in lower latitudes.

Graphs attached for 21 June.

ps: I will never know if my letter to the Cnadian High Commission did the trick on getting https://www.ccin.ca/ccw/snow/current to restart updates.


Title: Re: Northern Hemisphere snow cover
Post by: Neven on June 22, 2018, 02:03:49 PM
All the snow seems to be gone, except, of course, on the Tibetan Plateau.  ;)
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on June 22, 2018, 02:43:22 PM
All the snow seems to be gone, except, of course, on the Tibetan Plateau.  ;)

Wait till next year.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 22, 2018, 05:09:16 PM
All the snow seems to be gone, except, of course, on the Tibetan Plateau.  ;)
I know you are just being sassy but I see plenty of greens across Quebec / etc. They are not huge areas at this point but the anomalies are nevertheless significant, especially with insolation currently at peak, which amplifies their contribution to the cryosphere.

I still think the Tibetan Plateau anomalies are legitimate. They have grown into the spring, they weren't distributed like ^ all winter. I suspect precipitation is increasing even more in low vs. high latitudes due to proximity to oceanic heat content.

For reference, it was snowing / freezing rain-ing on Mauna Loa and Mauna Kea this month. That is @ 13,000' in the middle of the Pacific, it is hardly inconceivable that altitudes of 10,000'+ in the Himalayas (much closer to cold air sources and generalized albedo that is more favorable to retaining cold) would or could be among the first signs of impending advances in SWE first, glaciers second.
Title: Re: Northern Hemisphere snow cover
Post by: Neven on June 22, 2018, 05:27:25 PM
Yes, I'm being a bit sassy.  ;)

But it's a feature that still intrigues me.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 22, 2018, 11:09:25 PM
Yes, I'm being a bit sassy.  ;)

But it's a feature that still intrigues me.
You know what intrigues me? Quebec! We could be only 60-90 days or so from the start of winter for areas adjacent to whatever ice is most resilient in Foxe Basin and Baffin Bay.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018062212/ecmwf_T850_namer_10.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 23, 2018, 04:14:39 AM
The shift from 2012 -> 2018 is due to our hitting an inflection point re: impact of oceanic heating some point around then. The situation re: continental albedo since then has quickly evolved into "absurd" territory concurrent with continued oceanic warming / decay of high altitude sea ice.

It looks like 2018 is essentially a more "evolved" version of the 2012 pattern. The NATL vortex is now displaced over Greenland due to the tremendous fall in NATL ice / Greenland ice since 2012. This shift allows it access to much colder source air / also puts much more snow onto Greenland and could also help explain why we see the worsening blues over Quebec (Greenland is a source region) and NW Africa.

At the same time, the increasingly potent cold plunges SW / SE from Greenland lift more heat up from Eurasia / etc (and GHGs amplify continental heating when snowfall is lacking, esp at night). Combined with the worsening albedo anomalies in the high mid-latitudes the effect is disastrous on the sea ice.

In fact, the picture this June over much of the Arctic is far worse than what it saw in 2012. I think it is even more important that the sequence of melt in 2018 is going to allow for much more open water in high latitudes much earlier on than in 2012 (remember our extent etc is still buffered by Hudson and Kara). This will allow more insolation to accumulate and may create the worst September / October couplet for the sea ice on record.
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on June 23, 2018, 06:46:04 AM
The ARCUS SIPN report is out for predictions of Sept SIE based on May data :

https://www.arcus.org/sipn/sea-ice-outlook/2018/june

Median projection this year is 4.6 M km2.
Incidentally, that is pretty close to my estimate of 4.65 M km2 which was based on the Northern Hemisphere albedo (snow cover, ice 'area' and 'extent') in the report.

(https://www.arcus.org/files/resize/sio/28244/2018_sio_june_report_fig1_arctic_sorted_extent_horiz_v3_22june-700x509.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 24, 2018, 08:08:31 PM
https://www.forbes.com/sites/brianbrettschneider/2018/06/20/unprecedented-change-from-cold-april-to-hot-may/#132b1b491d47
Title: Re: Northern Hemisphere snow cover
Post by: ReverendMilkbone on June 25, 2018, 02:40:28 AM
Anyone here ever played with Google Earth Engine? (Satellite view time lapse starting in 1984)  Does a great job of showing shrinking glaciers;

Columbia Glacier;  https://earthengine.google.com/timelapse/#v=61.06005,-146.83644,8.361,latLng&t=1.30

But also if you zoom out and look at the entirety of North America you can see a sharp reduction in snow cover.  Is this real snow loss or an illusion caused by enhanced satellite imagery? Watch for several loops, notice how the snow snaps back when it returns to 1984.

https://earthengine.google.com/timelapse/#v=68.21841,-109.73974,1.673,latLng&t=0.14
Title: Re: Northern Hemisphere snow cover
Post by: oren on June 25, 2018, 03:18:26 AM
Anyone here ever played with Google Earth Engine? (Satellite view time lapse starting in 1984) 
Never heard of it. Thanks for the link!
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on June 26, 2018, 05:18:49 AM
But also if you zoom out and look at the entirety of North America you can see a sharp reduction in snow cover.  Is this real snow loss or an illusion caused by enhanced satellite imagery? Watch for several loops, notice how the snow snaps back when it returns to 1984.

https://earthengine.google.com/timelapse/#v=68.21841,-109.73974,1.673,latLng&t=0.14

Thanks for that Google Earthengine site. That's a really cool tool.

Regarding the disappearing land snow cover since 1984, I think it is real.
Rutgers snow lab shows a remarkable decline for the month of June over the decades :
https://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6
Title: Re: Northern Hemisphere snow cover
Post by: Daniel B. on June 26, 2018, 07:29:42 PM
Still snowing in Newfoundland.

https://weather.com/news/news/2018-06-26-late-june-snow-newfoundland-canada (https://weather.com/news/news/2018-06-26-late-june-snow-newfoundland-canada)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on June 30, 2018, 12:38:54 AM
Still snowing in Quebec!

(https://www.tropicaltidbits.com/analysis/models/gem/2018062912/gem_asnow_namer_40.png)
Title: Re: Northern Hemisphere snow cover
Post by: Brigantine on June 30, 2018, 01:05:26 AM
Still snowing in Quebec!

The subtle difference between "it is forecast to snow 10 days (!) from now" and "it is currently snowing"
(like Newfoundland 4 days ago)

10 day forecasts come with extra salt.

Meanwhile snow cover is starting to blink out on Baffin Island - in the Western end and in a spot to the west of Cumberland Sound. Victoria Island is mostly snow free now. Summer has arrived in the CAA.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on July 01, 2018, 11:31:19 AM
https://www.ccin.ca/ccw/snow/current

Sorry, but methinks "snowmageddon" is postponed, at least until next year. The new ice age will have to wait.

The attached map shows there is snow still lying here and there much later than usual, but mostly only 5-10 cm depth.

The North America extent and SWE graphs also show higher extent and SWE than average, but nothing like they were earlier in the year.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on July 01, 2018, 04:57:46 PM
https://www.ccin.ca/ccw/snow/current

Sorry, but methinks "snowmageddon" is postponed, at least until next year. The new ice age will have to wait.

The attached map shows there is snow still lying here and there much later than usual, but mostly only 5-10 cm depth.

The North America extent and SWE graphs also show higher extent and SWE than average, but nothing like they were earlier in the year.
??? We are already dealing with catastrophic impacts. Greenland is also still whiter than normal. As are the Himalayas / elsewhere. A limited area at peak insolation is as impactful as a broad area at polar night.

I agree that Quebec etc is not yet re-glaciating but parts are still under 1M+ of cover. We may not have to wait more than another few years for coverage to make it through August. I would classify our current situation as "snowmaggedon" even if it isn't yet at the stage of glacial advance over wide regions.

Here is 2018 versus 2012, March to May. Look at the North Atlantic! And the North Pacific. They are now getting worse on both ends in tandem.

Another interesting thing to note is the attached comparison of 2014 to 2012. It looks remarkably similar to 2018. If you roll that year forward, the winter featured extremely severe cold across many regions, roughly correlated with Jan-May anomalies.

Versus 2014, 2018 has been substantially colder across the areas S of Kara. And Kara itself. I would think combined with the precedent over N America this portends an extremely and brutally cold and snowy winter across much of Eurasia and North America.

It may also mean that the Bering will not refreeze much at all in the winter of 2018-19!
Title: Re: Northern Hemisphere snow cover
Post by: jai mitchell on July 01, 2018, 05:20:29 PM
I agree that Quebec etc is not yet re-glaciating but parts are still under 1M+ of cover. We may not have to wait more than another few years for coverage to make it through August. I would classify our current situation as "snowmaggedon" even if it isn't yet at the stage of glacial advance over wide regions.

 ??? ??? ??? ??? ???

https://www.youtube.com/watch?v=kbQWXc67GPg
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on July 01, 2018, 05:56:21 PM
I agree that Quebec etc is not yet re-glaciating but parts are still under 1M+ of cover. We may not have to wait more than another few years for coverage to make it through August. I would classify our current situation as "snowmaggedon" even if it isn't yet at the stage of glacial advance over wide regions.

 ??? ??? ??? ??? ???
Quebec City is not all of Quebec FYI.

(https://weather.gc.ca/data/analysis/352_50.gif)
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on July 01, 2018, 07:15:00 PM
In volume it can not be that much, if this pic is correct. But it shows how much meltwater entered the sea in just 14 days. From half way April until the start of May, that's like 800 km3. Normaly it takes 2 months to unload that volume.

Is there any data about the temperature of the water in the rivers in Canada ? It's getting hot there in the next weeks, and there is some rain. That should give the opposite situation, compared to the meltwater from last months.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on July 01, 2018, 07:19:47 PM
In volume it can not be that much, if this pic is correct. But it shows how much meltwater entered the sea in just 14 days. From half way April until the start of may, that's like 800 km3. Normaly it takes 2 months to unload that volume.

Is there any data about the temperature of the water in the rivers in Canada ? It's getting hot there in the next weeks, and there is some rain. That should give the opposite situation, compared to the meltwater from last months.
I would say NATL anomalies are a reasonable proxy. For now, everything is frigid.

Title: Re: Northern Hemisphere snow cover
Post by: oren on July 01, 2018, 07:33:03 PM
I agree that Quebec etc is not yet re-glaciating but parts are still under 1M+ of cover. We may not have to wait more than another few years for coverage to make it through August. I would classify our current situation as "snowmaggedon" even if it isn't yet at the stage of glacial advance over wide regions.

 ??? ??? ??? ??? ???
Quebec City is not all of Quebec FYI.
Seriously, snow melt-out dates have been less than 2 weeks late compared to normal, and not far from normal variability. The locations of current Quebec snow are not even where the snow depth anomalies have been concentrated in April, all those areas have melted a long time ago. Nothing suggests pending glaciation. Nothing.
Title: Re: Northern Hemisphere snow cover
Post by: jai mitchell on July 01, 2018, 09:11:41 PM
I agree that Quebec etc is not yet re-glaciating but parts are still under 1M+ of cover. We may not have to wait more than another few years for coverage to make it through August. I would classify our current situation as "snowmaggedon" even if it isn't yet at the stage of glacial advance over wide regions.

 ??? ??? ??? ??? ???
Quebec City is not all of Quebec FYI.
Seriously, snow melt-out dates have been less than 2 weeks late compared to normal, and not far from normal variability. The locations of current Quebec snow are not even where the snow depth anomalies have been concentrated in April, all those areas have melted a long time ago. Nothing suggests pending glaciation. Nothing.

We prevented pending glaciation with the advent of early human agriculture in 5,000 B.C.E. and especially with rice cultivation in 3,000 B.C.E.  whose absence would have produced glaciation conditions forming around 0 A.D. and would have certainly taken hold by the mid 1800's. 

We won't see another ice age for at least 200,000 years and probably longer.

much much much longer.

(https://media.springernature.com/full/nature-static/assets/v1/image-assets/ngeo2997-f1.jpg)
Title: Re: Northern Hemisphere snow cover
Post by: jai mitchell on July 01, 2018, 09:17:52 PM
https://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2018&ui_day=181&ui_set=0

Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on July 04, 2018, 08:26:05 AM
Rutgers published the June numbers for Northern Hemisphere land snow cover.
It's still higher than most of the past 10 years, but significantly below the 'average' number recorded in May.

The take-away message : A lot of snow melted in June.

Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on July 04, 2018, 06:36:55 PM
The Rutgers figure for June was 7.84 million km2. That is a departure of -1.58 million below the 1981-2010 mean.

There was more snow than usual over parts of the far east of Russia (Chukotka and Kamchatka) and northern Quebec but less than normal over western and northern Canada and north central Siberia.

Chart showing the monthly anomalies 2016 -2018 attached. It is proving difficult to get a positive anomaly during the summer months.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on July 05, 2018, 11:02:41 AM
I think this is my last post until it starts snowing again. As expected, despite the massive
winter / spring snowfall, the snow melted - just a bit late, is all.

https://www.ccin.ca/ccw/snow/current
Title: Re: Northern Hemisphere snow cover
Post by: Rob Dekker on July 07, 2018, 05:01:55 AM
Most of you will know that since 2013, I use I use the "whiteness" of the Arctic in June as a predictor for how much ice will melt out between June and September.

http://neven1.typepad.com/blog/2013/07/problematic-predictions-2.html

Specifically, I use three variables to make this prediction :
- Land snow cover in June
- Ice 'area' in June
- (Extent - Area) in June, which represents the amount of 'water' in the ice pack in June.

A combination of these variables, each one of which affects the 'albedo' of the Northern Hemisphere, represents how much solar energy gets absorbed by the Northern Hemisphere in summer, and this correlates remarkably well with September sea ice cover.

Details of this method is described in one of my entries into Arcus Sea Ice Prediction Network :

https://www.arcus.org/files/sio/25738/sio-2016-july_dekker.pdf

This year, land snow cover in June was quite high compared to recent years :

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=103.0;attach=104037;image)

Also, ice 'area' is quite high in June (in between 2014 and 2015) and the ice is still fairly compact.

As a result, prediction for Sept 2018 September sea ice extent is quite high at 5.19 km2, with a standard deviation of 340 k km2.

My gut feeling this year tells me that this an upper bound, but it's fairly clear that given the past performance of this method, it is highly unlikely (less than 2.5% chance) that Sept 2018 will end up below 4.5 M km2.

Here is what this hind-cast method did for the past 26 years :

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=292.0;attach=104209;image)

Comments and suggestions on this method are welcome in the "Re: Land snow cover effect on sea ice" thread :

https://forum.arctic-sea-ice.net/index.php/topic,292.msg162415.html#msg162415
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on July 21, 2018, 08:48:39 PM
"Alas, Snowmageddon, I knew you well"
Title: Re: Northern Hemisphere snow cover
Post by: oren on July 25, 2018, 08:30:52 AM
Following a discussion on another thread, here's a summary of snow trends in the Alps. Hat tip to Magnamentis who provided the link.

Quote
Snowpack responds to climate change
Thanks to the long-term measurement data, we have been able to identify some clear trends. The last 30 years have seen very low levels of snow, particularly on the Swiss Plateau. The trend towards less snowy winters at most stations below 1300 m is statistically significant. The lower the altitude of the observation station, the more apparent the changes are. By contrast, above 2000 m the snow depths in midwinter (December to February) show no clear trend. The same is not true of snow cover duration: the vast majority of stations are seeing a clear reduction in the number of days with snow-covered ground, regardless of their altitude or location. The primary reason for this is earlier snow melt in the spring. The delay of snow onset in autumn is also a factor at lower-altitude stations. In addition, the annual maxima for snowfall and snow depths have tended to decline at all stations over recent decades.

https://www.slf.ch/en/snow/snow-and-climate-change.html (https://www.slf.ch/en/snow/snow-and-climate-change.html)
Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on July 25, 2018, 03:13:18 PM
Tamino recently did a post on Colorado, USA snow trends:
Global Warming: Let It Snow (https://tamino.wordpress.com/2018/07/23/global-warming-let-it-snow/#more-9925). The results of his inquiry would not be surprising to anybody who frequents these threads or his posts.
Quote
...
But 15 stations [in Colorado] show statistically significant rates of snow-out day, all of them trending earlier, and 15 reached significance for maximum SWE, all of them trending lower. This is not an accident. It’s the result of climate change. Man-made climate change.
...
SWE = snow water equivalent
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on July 25, 2018, 04:10:08 PM
Following a discussion on another thread, here's a summary of snow trends in the Alps. Hat tip to Magnamentis who provided the link.

Quote
Snowpack responds to climate change
Thanks to the long-term measurement data, we have been able to identify some clear trends. The last 30 years have seen very low levels of snow, particularly on the Swiss Plateau. The trend towards less snowy winters at most stations below 1300 m is statistically significant. The lower the altitude of the observation station, the more apparent the changes are. By contrast, above 2000 m the snow depths in midwinter (December to February) show no clear trend. The same is not true of snow cover duration: the vast majority of stations are seeing a clear reduction in the number of days with snow-covered ground, regardless of their altitude or location. The primary reason for this is earlier snow melt in the spring. The delay of snow onset in autumn is also a factor at lower-altitude stations. In addition, the annual maxima for snowfall and snow depths have tended to decline at all stations over recent decades.

https://www.slf.ch/en/snow/snow-and-climate-change.html (https://www.slf.ch/en/snow/snow-and-climate-change.html)

It would appear that, as the earth warms, we generally get less snow.  :)
Title: Re: Northern Hemisphere snow cover
Post by: crandles on July 25, 2018, 04:12:29 PM
It would appear that, as the earth warms, we generally get less snow.  :)

Or more melting  ;)
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on July 25, 2018, 08:51:53 PM
Following a discussion on another thread, here's a summary of snow trends in the Alps. Hat tip to Magnamentis who provided the link.

Quote
Snowpack responds to climate change
Thanks to the long-term measurement data, we have been able to identify some clear trends. The last 30 years have seen very low levels of snow, particularly on the Swiss Plateau. The trend towards less snowy winters at most stations below 1300 m is statistically significant. The lower the altitude of the observation station, the more apparent the changes are. By contrast, above 2000 m the snow depths in midwinter (December to February) show no clear trend. The same is not true of snow cover duration: the vast majority of stations are seeing a clear reduction in the number of days with snow-covered ground, regardless of their altitude or location. The primary reason for this is earlier snow melt in the spring. The delay of snow onset in autumn is also a factor at lower-altitude stations. In addition, the annual maxima for snowfall and snow depths have tended to decline at all stations over recent decades.

https://www.slf.ch/en/snow/snow-and-climate-change.html (https://www.slf.ch/en/snow/snow-and-climate-change.html)

It would appear that, as the earth warms, we generally get less snow.  :)
On Environment Canada I found a mention of a study showing that there is more snow at very high latitudes, and less at lower latitudes, and the snowline is moving up the slopes of the mountains. Seems a logical progression to me as water vapour increasing as are air temperatures.
No comment from BBR yet?
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on July 25, 2018, 08:55:05 PM
These studies do not include 2017 or 2018. It would be like a sea ice study that only went up to 2005. Inflection points matter but all these measurements compare to XX decades ago -- mostly meaningless. So I am not going to engage.
Title: Re: Northern Hemisphere snow cover
Post by: RikW on July 26, 2018, 09:23:02 AM
I think in the highest lattitudes there will be more snowfall, in other regions less. In the highest latitudes more evaporation will lead to more snow, in the lower latitudes the higher heat will reduce the area that is cold enough for snow and will cause more drought.

But that is not based on scientific field research, just some logical reasoning, which could make no sense at all
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on July 27, 2018, 03:13:21 AM
I'm working on a simple (non-gridded) version of my AWP anomaly model for the Northern Hemisphere land cover in order to quantify the effect of the increased snow extent we had the last few springs. There will still be a continental breakdown of Eurasia, North America and Greenland because the Latitude changes differently on each for the same snow extent values.

What's definitely clear is that the most important months are May and June. The autumn does hardly matter because the solar intensity is too low. Overall there is of course a strong warming trend. 2017 causes a drop in the 5 year moving average, and 2018 doesn't make up for it. (until June)

Maybe I finish it sometime in August and will post a better description and analysis on my website.
https://sites.google.com/site/cryospherecomputing/awp

All snow extent data is from Rutgers University:
https://climate.rutgers.edu/snowcover/table_area.php?ui_set=2

Here are some preliminary Graphs for the whole Northern Hemisphere.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on July 27, 2018, 03:16:13 AM
I'm working on a simple (non-gridded) version of my AWP anomaly model for the Northern Hemisphere land cover in order to quantify the effect of the increased snow extent we had the last few springs. There will still be a continental breakdown of Eurasia, North America and Greenland because the Latitude changes differently on each for the same snow extent values.

What's definitely clear is that the most important months are May and June. The autumn does hardly matter because the solar intensity is too low. Overall there is of course a strong warming trend. 2017 causes a slight drop in the 5 year moving average, but 2018 is similar to recent years.

Maybe I finish it sometime in August and will post a better description and analysis on my website.
https://sites.google.com/site/cryospherecomputing/awp

All snow extent data is from Rutgers University:
https://climate.rutgers.edu/snowcover/table_area.php?ui_set=2

Here are some preliminary Graphs for the whole Northern Hemisphere.
Can you please plot the derivative? I think it may have more value to the sea ice than absolute as it is indicative of trend instead of gross anomaly.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on July 27, 2018, 12:24:40 PM
Interesting contrast between North America SWE and SCE at this fag-end of the snow year.

SWE approaching zero while SCE still a good bit higher than average. Must be a low average snow depth ? This is the reverse of the situation during the snowfall period especially in February to April.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on July 27, 2018, 07:44:37 PM
Interesting contrast between North America SWE and SCE at this fag-end of the snow year.

SWE approaching zero while SCE still a good bit higher than average. Must be a low average snow depth ? This is the reverse of the situation during the snowfall period especially in February to April.

Fresh recent snow in areas that had been snow free?
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on July 27, 2018, 08:52:55 PM
Tealight, what exactly is the 2th graph showing us ?
Title: Re: Northern Hemisphere snow cover
Post by: Tealight on July 28, 2018, 01:42:58 AM
Can you please plot the derivative? I think it may have more value to the sea ice than absolute as it is indicative of trend instead of gross anomaly.

I will make all data available soon and then everyone can create their own investigations and graphs. More useful for sea ice are probably sub-seasonal time-frames like March to June or September.

Tealight, what exactly is the 2th graph showing us ?

It shows the anomaly of the maximum possible absorbed solar energy assuming clear sky conditions. The only difference between years is the snow extent (albedo of the land surface)
By the way I set the snow free land albedo as 0.25, snow covered albedo as 0.6 for the continents and snow albedo on Greenland as 0.8. Different values would not change the ranking between years, only make the differences larger or smaller.

---------------------------

I don't think absolute energy numbers are very intuitive or does anyone here know how 180*10^21 Joule influence the earth over 100 million square kilometer and 365 days?

Alternatively the data can be presented in percent.

e.g. In 2012 the land absorbed 1.9% more and in 1985 2% less energy compared to the long term mean.

edit: the differences are actually a bit higher than that. It's just difficult to estimate a good latitude and incoming solar energy with a non-gridded model. At least for now this issue reduces the differences between years in my model.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on July 30, 2018, 01:29:45 AM
Though limited, extant cover should survive in Quebec well into August...!

(https://weather.gc.ca/data/analysis/352_50.gif)
Title: Re: Northern Hemisphere snow cover
Post by: Brigantine on July 30, 2018, 04:38:37 AM
I'm not sure about "well into August", but as of 29 July there is still snow according to NIC.

2018:
(https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/AK/2018/ims2018210_alaska.gif)

2017 also had just a speck, in the same place on Uganva peninsula:
(https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/AK/2017/ims2017210_alaska.gif)

2013 was in-between - there were several small specks: (The last one finally disappeared on August 2)
(https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/AK/2013/ims2013210_alaska.gif)
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on July 30, 2018, 06:18:56 PM
By the way I set the snow free land albedo as 0.25, snow covered albedo as 0.6 for the continents and snow albedo on Greenland as 0.8.

I was just comparing the western section of the Greenland Ice Sheet on Worldview and noticed this time last year the surface at the edges of the sheet were a lot more grey coloured than this year. Similar grey edges 2017 vs whiter edges 2018 were observed at other parts of the Greenland sheet also.

I am not sure whether this is down to enhanced July melt conditions last year vs this year (although the NSIDC graph does not show much difference between the two years) or whether it is smoke/dust/particulate related or maybe even different Worldview visual processing between the two years ?
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on July 31, 2018, 12:12:55 PM
North America Snow Cover Extent at 30 July is still more than 1 standard deviation above the average, just about exactly the same as at the beginning of the snow year (1st August 2017). i.e. as near as makes no odds, last year's snow year ended up in the same place as this year. Snow Water Equivalent (Km3) is minimal.

ps:- And although Hudson bay was late and slow to melt (and logic says that must be partly due to loads of snow), area is now in the same place as just about every year, i.e. well under 10% of maximum. At an average latitude around 60o North, plenty of time for this very shallow sea to warm up per usual before the freeze.

https://www.ccin.ca/ccw/snow/current
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on August 01, 2018, 01:50:30 PM
Environment Canada has a snowfall year of August to July - so yesterday was the end of the 2017-
18 year. Attached are the July 31 graphs.

By winter spring 2018-19 it looks like an El Nino will be in place. It will be interesting to see if that has an effect of snowfall (and to see how bbr2314's snowmageddon develops). Apart from a peek now and then to see how much more snow melts during August,  I guess I will put this thread into sleep mode until at least mid-September.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 07, 2018, 01:15:24 AM
Oh la la

L'hiver approche rapidement

Il neige a Quebec, peut etre la neige dans la nord vivre sur tous l'ete? Maintenant c'est vraiment possible!

(https://www.tropicaltidbits.com/analysis/models/gem/2018080612/gem_asnow_namer_40.png)
Title: Re: Northern Hemisphere snow cover
Post by: colchonero on August 07, 2018, 02:39:38 AM
Oh la la

L'hiver approche rapidement

Il neige a Quebec, peut etre la neige dans la nord vivre sur tous l'ete? Maintenant c'est vraiment possible!

(https://www.tropicaltidbits.com/analysis/models/gem/2018080612/gem_asnow_namer_40.png)


Bbr are you French? And why aren't you ;D? No man, just kidding about some grammar there, nice post and we'll see if the forecast will hold in the next couple of days.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 07, 2018, 03:07:35 AM
Oh la la

L'hiver approche rapidement

Il neige a Quebec, peut etre la neige dans la nord vivre sur tous l'ete? Maintenant c'est vraiment possible!

(https://www.tropicaltidbits.com/analysis/models/gem/2018080612/gem_asnow_namer_40.png)


Bbr are you French? And why aren't you ;D? No man, just kidding about some grammar there, nice post and we'll see if the forecast will hold in the next couple of days.
Je parle parfait franglais -- mon francais est seulement moyenne, desolee :(
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 07, 2018, 12:13:35 PM
EURO wants winter to begin early across much of the Shield while the Arctic absolutely torches thanks to all the latent heat release from severe tropical cyclones in the PAC:

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018080700/ecmwf_T850_namer_11.png)
Title: Re: Northern Hemisphere snow cover
Post by: Niall Dollard on August 08, 2018, 07:22:06 PM
Rutgers NH snow cover figure for July was 3.01 million km2.

That is a negative departure of -0.66 million km2.

This is the third monthly negative departure in a row, but the departure for July was not as big as that of July 2016.

Negative departures were over Kamchatka, north tip of Siberia, western Canada and the southern CAA

Positive departures were over southern Baffin, NE Quebec and the north CAA.
Title: Re: Northern Hemisphere snow cover
Post by: Shared Humanity on August 09, 2018, 05:02:18 AM
Puts away parka and snow shoes.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 09, 2018, 02:01:39 PM
Winter is cominggggg!  ;D

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018080900/ecmwf_T850_namer_3.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018080900/ecmwf_T850_namer_6.png)

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018080900/ecmwf_T850_namer_11.png)

Repeated and generally sustained cold should mean that snows will once again be falling fairly consistently across higher terrain. Also, Foxe Basin's forecast is C-O-L-D. I wonder if much of its ice is retained? Conditions for melt through D10 look generally unfavorable or actually positive for snowfall.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 12, 2018, 10:16:02 PM
I think it may be time for a new thread on the 2018-19 winter and what I think will unfold. I have seen some discussion amongst friends that the Gulf Stream is either now failing more completely or shifting modes substantially (i.e., shifting in the same way that FRAM export is now close to 0 because all the ice melts out before it can get exported).

This link contains charts that are quite fascinating in illustrating how severe and unprecedented this past April was across much of the US. Interestingly, while other cool periods in winter are characterized by lower maxes than mins vs. normal (usually), this past April saw lower MINIMUMS than maximums vs. normal.

In fact, this past April was the *coldest on record* for minimums across a vast swath of Middle America (as well as absolute averages over a smaller portion).

https://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl

Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 13, 2018, 01:02:15 AM
First run of the GFS with extremely substantial totals in Quebec and falls across areas of Canada S of Nunavut:

(https://www.tropicaltidbits.com/analysis/models/fv3p/2018081212/fv3p_asnow_namer_41.png)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 16, 2018, 06:40:27 PM
Q: What do you call it when snow survives the summer across certain areas where it normally doesn't?

A: Re-glaciation!

New GFS, CMC, and EURO (shown below) are all showing sustained falls now occurring through D10, not without intermittent melt, but whatever melt there is will be overwhelmed by feet of new snow. It's happening (?)

(https://weather.gc.ca/data/analysis/352_50.gif)
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 16, 2018, 08:52:13 PM
The 12z EURO appears much more aggressive with re-establishing the cryosphere across the Canadian shield, I suspect this is due to all the heat in the PAC front and Laptev.

850s are off and on below 0 until 168 when first major-ish blast comes through.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018081612/ecmwf_T850_namer_8.png)

By 216 cold is loading into NWT and Yukon. I suspect EURO is also being too progressive with removing cold from Quebec (as it has been most months this year). Winter is just about here for much of the Canadian Shield...

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018081612/ecmwf_T850_namer_10.png)

It looks like the +500MB anoms over Pac front / Laptev have tightened the persistent -500MB vortex over Greenland that has dominated this summer's weather, and as a result, it will continue firing rapid blasts of -GAK airmasses into NW Canada / Quebec.

(https://www.tropicaltidbits.com/analysis/models/ecmwf/2018081612/ecmwf_z500aNorm_namer_10.png)

Snow-liquid equivalent through hr 204

Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on August 16, 2018, 08:52:43 PM
"A glacier is a large, long-lasting mass of ice found on land that moves because of gravity." (link (http://www3.geosc.psu.edu/~jte2/geosc20/lect14.html))  A snowfield is not a glacier.  Perennial ice that does not move is not a glacier.  If you want to read about a new glacier, look to Mt. St. Helens' Crater Glacier (https://en.wikipedia.org/wiki/Crater_Glacier).
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 16, 2018, 09:32:34 PM
"A glacier is a large, long-lasting mass of ice found on land that moves because of gravity." (link (http://www3.geosc.psu.edu/~jte2/geosc20/lect14.html))  A snowfield is not a glacier.  Perennial ice that does not move is not a glacier.  If you want to read about a new glacier, look to Mt. St. Helens' Crater Glacier (https://en.wikipedia.org/wiki/Crater_Glacier).
I said re-glaciation has begun, not that it was a glacier. We will have to wait a few more years for perennial snowcover to result in "glaciers" but the process "re-glaciation" is now underway, IMO.

It should be noted that the maps for climate at -1C vs today show "glacier accumulation zones" covering precisely the areas that are now seemingly seeing perennial snowcover.

(https://climatereanalyzer.org/clim/ecm/images/ECM_5_1_12_-1.jpg)

While temps in NRN Quebec were WAY warmer than normal during winter, so far this summer (when warmth vs. normal is relative to melt, instead of resulting in +++snowfall), temps have been way below normal. In fact, since 6/1, large swaths of Quebec have been up to -2.5C vs. normal.

I think people are conflating what is necessary for perennial snowcover to exist. We need SUMMERTIME temps of -1C or lower vs. averages for perennial snowcover in the highest regions, and from -3C or lower in the lower elevations of Quebec. The only critical period for negative anomalies is in between the start of melt and the start of new snows -- and the longer melt is held off, the quicker new snows begin falling due to remaining extant cover and residual sea ice in the vicinity (i.e. Foxe Basin still has substantial thick ice). If wintertime temps average -20C, a +10C three-month departure from Dec to Feb only serves to allow more moisture and thicken the snowpack. On the otherhand, if that +++wintertime departure is matched by a -2 or -3C JJA anomaly, we see snows remain extant through summer and re-glaciation begins very rapidly.

Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on August 16, 2018, 10:35:22 PM
bbr2314,
You actually wrote "Re-glaciation!" and ended "It's happening (?)"
(To the question, I'll sadly reply: I doubt it.)

I am curious whether Climate Reanalyzer's "Global Δ=-1ºC" is in relation to today or to 1850 (or 1700), given that we are currently at +1ºC over pre-industrial.  Do you have a link that says?
Title: Re: Northern Hemisphere snow cover
Post by: magnamentis on August 16, 2018, 11:19:10 PM
after two years of one extreme theories following the other and that not in one field of expertise but basically across the board of topics, i clearly see this as trolling and only recommend to stop replying, it's the only means beside a ban that can stop a troll with a healthy mind and
then there are others who pretend not to care. reminds me of POTUS behaviour, uttering
one utter BS after another, not fearing the consequences and not one single time admitting
an error or that it might perhaps be a bit far fetched, instead insisting to the bitter end and once the topic is worn out find another one.

if i only had time i'd start making a list from split CAB to swiss-cheese like greenland to .......

even though i found a way that most of it goes past me i stlll can read the replies and the quotes which at times renders the purpose of some features obsolete.

doubts are a very nice term to express that we know that the opposite is happening and increasingly though. it's best denier's practice to find one or two spots on the globe that behave differently and then claim that everything is the other way around.

last but no least before i wrote this i can claim that i tried with dozens of friendly hints to stop the
nerve-killing provoking posts without any benefit but to stand out from to mass like if opposition would be a virtue that's disconnected from the cause.


Title: Re: Northern Hemisphere snow cover
Post by: oren on August 16, 2018, 11:33:06 PM
Well said Magna. I'm trying to restrain myself and ignore but the speculative fiction is hard on the nerves.
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on August 17, 2018, 12:10:47 AM
Maybe he really beliefs it. And if you don't belief him, is there no way to tell he's wrong. Like the places where it was colder this year. Maybe it's just about the condition of the polar vortex. Like we had cameleons falling from trees in Florida. That probably don't happens much, but it did this year. Or like in 2012 when the Bering Sea was much more frozen than normal.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 17, 2018, 12:17:08 AM
Maybe he really beliefs it. And if you don't belief him, is there no way to tell he's wrong. Like the places where it was colder this year. Maybe it's just about the condition of the polar vortex. Like we had cameleons falling from trees in Florida. That probably don't happens much, but it did this year. Or like in 2012 when the Bering Sea was much more frozen than normal.
I do believe it. There are maps etc verifying these claims. However, ignorance is bliss, so I do not fault others who think I am "trolling" or whatever.

These are usually the same posters who express faith in humanity's ability to resolve AGW / catastrophic climate change as if their own behavior isn't part of the problem (and this is amongst posters at a site where scientific literacy is FAR higher than amongst the general public). I don't know how people think there will be any improvements when the impending changes due to agricultural shortages etc will overwhelm any efforts towards "greening" consumption. And even then, "greening" consumption in and of itself is sufficient to push planetary averages to +2-+2.5C vs. 1900 baseline due to dropping aerosols.

To the posters ranting about myself in the above comments: why has Quebec been colder than ANY OTHER SUMMER in recent times this year? Why did parts of the Midwest experience their coldest April on record, going back to 1895, and under GHGs that are +50% vs 1895? There is a simple explanation (+++precip = +++snow = +++albedo, combined with +++oceanic heat = Gulf Stream shutdown). But if you don't like the explanation we already have historical evidence of in the Younger Dryas, please make up your own theories (and of course the criticism will start with ....BUT LAKE AGASSIZ...!!! when GREENLAND has way more volume).
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 17, 2018, 12:23:31 AM
bbr2314,
You actually wrote "Re-glaciation!" and ended "It's happening (?)"
(To the question, I'll sadly reply: I doubt it.)

I am curious whether Climate Reanalyzer's "Global Δ=-1ºC" is in relation to today or to 1850 (or 1700), given that we are currently at +1ºC over pre-industrial.  Do you have a link that says?
I believe it is vs. 1979-2000 avgs.

(https://climatereanalyzer.org/clim/ecm/images/ECM_5_1_12_0.jpg)

I would also like to note the posters ranting and raving ^^^ were the ones saying I was insane back in the spring. Now, months later and with extant snowcover remaining over Quebec, I have apparently "lost my mind" and am "trolling" when satellites confirm snow has remained extant over the summer.  :o
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on August 17, 2018, 12:54:05 AM
To be honestly , i'm not convinced. Why was it the coldest April in the Midwest ? Maybe it was because there was very little ice in the Bering Sea. So the cold was not there, that's for sure. Otherwise it would have been frozen much further. And there was not that much ice near Svalbard. So both on the Pacific and the Atlantic side there was not that much ice . There was some tick ice on the siberian  side and on the side of Canada. But is that not more related to that polar vortex ?
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 17, 2018, 01:13:30 AM
To be honestly , i'm not convinced. Why was it the coldest April in the Midwest ? Maybe it was because there was very little ice in the Bering Sea. So the cold was not there, that's for sure. Otherwise it would have been frozen much further. And there was not that much ice near Svalbard. So both on the Pacific and the Atlantic side there was not that much ice . There was some tick ice on the siberian  side and on the side of Canada. But is that not more related to that polar vortex ?
I think you are correct re: it also being related to ^^^. But the retreat of the ice in both the far NATL and Bering is also due to the shifting ocean currents / increase in oceanic heat content.

The question is whether we see a repeat this year. With all the insolation sopped up since 2017, I see no reason why we wouldn't, especially as we are likely to see a lower minimum than 2017 (and much less ice in both respective areas at minimum, as well as more accumulated heat).
Title: Re: Northern Hemisphere snow cover
Post by: Tor Bejnar on August 17, 2018, 04:22:43 AM
...
I am curious whether Climate Reanalyzer's "Global Δ=-1ºC" is in relation to today or to 1850 (or 1700), given that we are currently at +1ºC over pre-industrial.  Do you have a link that says?
I believe it is vs. 1979-2000 avgs.

[image showing Δ=0ºC for 1979-2000]
...
Thanks, bbr.  Were snowfields (or glaciers) growing in northern Quebec in 1700 the last time we were at Global Δ=-1ºC (compared with 'now').  Of course, other things were different then, like CO2 levels were lower.

Another question would be:  how in the world could we get to Global Δ=-1ºC (compared with 'now'), given ACC?  A couple regions in the world, sure, due to seriously changed winds or currents, while every place else broils or bakes, but global average temperature is basically going up.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 17, 2018, 05:02:22 AM
...
I am curious whether Climate Reanalyzer's "Global Δ=-1ºC" is in relation to today or to 1850 (or 1700), given that we are currently at +1ºC over pre-industrial.  Do you have a link that says?
I believe it is vs. 1979-2000 avgs.

[image showing Δ=0ºC for 1979-2000]
...
Thanks, bbr.  Were snowfields (or glaciers) growing in northern Quebec in 1700 the last time we were at Global Δ=-1ºC (compared with 'now').  Of course, other things were different then, like CO2 levels were lower.

Another question would be:  how in the world could we get to Global Δ=-1ºC (compared with 'now'), given ACC?  A couple regions in the world, sure, due to seriously changed winds or currents, while every place else broils or bakes, but global average temperature is basically going up.
There is no data I have been able to find re: 1700-1800 far northern glaciation / etc. I think there were basically only fur trappers in the area at the time and they probably didn't even get that far north (outside of Native Americans / Inuits).

And re: point #2 -- we definitely *will not* get to global -1C without major and catastrophic hosing. But I am not talking about global -1C, I am talking regionally in a specific area (NRN Canada). However, this could result in an albedo spiral that DOES result in a major drop in global temps, it will just take several decades for regional impacts to cascade elsewhere.
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on August 17, 2018, 09:31:49 AM
If we would go to a global -1 , your theory well have a problem. Because than there will be less evaporation from the oceans. So where will that extra snow come from ?  We have been cutting down as much vegatation as we could. We build the cities as big as we could. It's going to be a cold desert i think , but no glaciers.
Title: Re: Northern Hemisphere snow cover
Post by: gerontocrat on August 17, 2018, 12:03:36 PM
Be afraid, be very afraid!

No matter that ENSO  neutral is due to become El Nino over the next few months,
No matter that it is suggested that natural temperature variation may well pump up AGW in the next few years,

Snow has persisted in some hilly bits of Quebec!!!!!

Glaciation is upon us !!!!!!! (Also imagine a Buddy on font size)

Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 17, 2018, 06:44:17 PM
Be afraid, be very afraid!

No matter that ENSO  neutral is due to become El Nino over the next few months,
No matter that it is suggested that natural temperature variation may well pump up AGW in the next few years,

Snow has persisted in some hilly bits of Quebec!!!!!

Glaciation is upon us !!!!!!! (Also imagine a Buddy on font size)
You are being petulant and nasty for no reason. Both of those factors are likely to aggravate what is happening in Quebec due to +precip and +melt into the NE NATL. Your cold frozen corpse won't remember how rude you were on weather forums so why don't you try to add something of value instead of responding with attacks laced in bare-bones facts?

14-15 was a weak ENSO and led to the worst conditions we've seen in Eastern North America since the Little Ice Age (until this year, at least from April through summer, when 2018 was far colder across the NRN tier). I suspect +++ENSO actually has something to do with late extant snowcover across Eastern North America, I am not sure what yet, but the major event in 2015 followed the happenings of the previous winter, and I believe 1972 was also a very bad / cold snow year for Quebec (as in, there was a lot).

In any case, the models are now spreading snowfalls farther and farther across the Canadian shield by D10. Another notable development is being discussed in the melting thread, where ATeam seems to have ascertained that there has been a severe shift in the Beaufort Gyre, which could have released 20-30,000KM^3+ of freshwater toward the CAA and NE NATL (it will take months to get there). That amount of freshwater in such a short timeframe could cripple the NATL worse than what happened this year, especially if spring 2019 yields even more accumulated SWE than 2018.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 17, 2018, 08:53:47 PM
The latest EURO ups the ante once more. Wow. Deep, and increasingly widespread snows now being forecast over the NRN tier of Quebec. It should only be another week or two until we see falls across the lower altitudes + latitudes as well. For August, this is quite remarkable IMO.

Title: Re: Northern Hemisphere snow cover
Post by: Brigantine on August 17, 2018, 09:20:49 PM
How does the snow on the Barnes Ice Cap compare with the mountain snow patches on the Uganva Peninsula?

Over in Scotland they're doing a survey of mountain snow patches over the next few days. It's relatively touch and go whether any will survive the summer this year.
Title: Re: Northern Hemisphere snow cover
Post by: bbr2314 on August 17, 2018, 09:44:37 PM
How does the snow on the Barnes Ice Cap compare with the mountain snow patches on the Uganva Peninsula?

Over in Scotland they're doing a survey of mountain snow patches over the next few days. It's relatively touch and go whether any will survive the summer this year.
Checking EOSDIS, 2018 has a higher albedo than any other recent year. It looks like it is actually growing in elevation in the middle, but overall expansion is not yet occurring. The mountains of Baffin Island are also noticeably whiter / more snow-covered this year vs. any other.
Title: Re: Northern Hemisphere snow cover
Post by: Alexander555 on August 17, 2018, 10:34:52 PM
He Gerontocrat, i know it's a little off topic. But when that El Niño kicks in. Does it also has an impact on that piece of sea between West-Africa and the north of South-America. Because the water there is already colder than normal for the entire year. And that area is a little bit the origine for the rain in Europe. And colder water is less evaporation. And so far we had a pretty dry summer. Or is the impact from El Niño only situated between Asia and South- America ? I think that some kind of US wheater service predicts a less than normal US hurricane season for this year, because that seawater below the equator between West-Africa and South-America is colder than normal.