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Lord M Vader

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The 2018 melting season
« on: March 19, 2018, 08:12:14 PM »
As the SIE has dropped the last few days and the forecast calls for southerlies to enter Berings Sea now I think we can call the maximum and also declare the 2018 Melting season started! And I think a lot of people here thinks it quite fitting to start the melting season thread with a century break... :)

Personally, I think we will end up somewhere around 4,5 Mn km2 by the middle of September.

Now, let's get this show on the road! :)
« Last Edit: March 19, 2018, 08:24:13 PM by Neven »

Neven

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Re: The 2018 melting season
« Reply #1 on: March 19, 2018, 08:23:36 PM »
If JAXA drops tomorrow and the day after that, I'll unlock this thread.

We must respect the maximum!  ;)
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Re: The 2018 melting season
« Reply #2 on: March 21, 2018, 08:19:44 AM »
Thread unlocked. Here we go!

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Re: The 2018 melting season
« Reply #3 on: March 21, 2018, 08:38:31 AM »
 .
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A-Team

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Re: The 2018 melting season
« Reply #4 on: March 21, 2018, 08:55:14 AM »
Winter freeze season pre-conditioning is important to summer melt season. I am just staking out some real estate here on Page One to hold year-to-date summary time series at a stable, easily navigable location, in the manner of wipneus on the piomas forum. These will be periodically updated and provide basic reference files for newcomers to the site.

Note there's considerable overlap with Neven's admirable collection of 81 sea ice graphics, the difference being only water vapor at bottom is animated and all are transient (not archived). Seven of these are not working this morning due to problems at various remote host servers.

https://sites.google.com/site/arcticseaicegraphs/

All of the animations will use the standard NSIDC map of the Arctic Ocean: the polar stereographic projection about the north pole, with Greenland in the down position. The maps will be similarly scaled to forum bounds which amounts to 650 pixels between the Bering Strait and Svalbard.

The first four of these include Ascat radar scattering off the ice from January 1st to the current date. Ice roughness corresponds fairly well to both ice age and ice thickness. At an mp4 speed of 9 frames a second (ie 9 days), ice movement is exaggerated by a factor of 777,600.



The OSI SAF graphic of daily ice motion is very well done. Note it also shows open water and dodgy ice as two shades of blue, thus incorporating information that otherwise might come from UH AMSR2. The first 80 days of 2018 are shown below, both as an mp4 and as summary graphic.

http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2018&month=03&day=20&action=Today&prod=LR-Drift&area=NH&size=100%25
« Last Edit: March 22, 2018, 04:39:30 PM by A-Team »

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Re: The 2018 melting season
« Reply #5 on: March 21, 2018, 08:56:45 AM »
I am just staking out more real estate here on the first page to hold more year-to-date summary time series at a stable location. These will be periodically updated and serve as basic reference files for newcomers to the site.

I'll add the best journal citations for people wanting to look more into details of how academic and agency climate scientists derive the files from satellite imagery.

The first four of these includes UH AMSR2 sea ice concentration from January 1st to the current date. This is similar to ice area and extent but has much higher nominal resolution, up to 3.125 km, and provides both a detailed land mask and a daily open water mask. This time of year, most of the Arctic Ocean has 100% sea ice concentration (pure white)so the time series mostly shows solid white. That will change though on the periphery as the melt season progresses.

On the technical side, it's feasible to change out the bright red for a less distracting color, change out the white to distinguish areas at less than 100% concentration, count and graph pixels of open water, add back the color key and so forth. Unfortunately the netCDF file is not georegistered and so the map cannot be redrawn without the lat,lon lines or switched to a linear gray palette.
« Last Edit: March 21, 2018, 09:59:33 AM by A-Team »

A-Team

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Re: The 2018 melting season
« Reply #6 on: March 21, 2018, 08:58:39 AM »
More winter pre-conditioning data relevant to summer 2018 melt season will be presented on this third bit of Page One real estate. The data summaries below will be periodically updated to serve as convenient reference files for newcomers to the site.

The third set of four of these will include various sea ice thicknesses from January 1st to the current date. The first is SMOS ice thickness (really thinness as it only shows ice to 0.5 m) from UniBremen. The scale will be added back in a bit.

The other SMOS ice thinness product from Hamburg is offered solely as a netCDF, which is better in many ways but is more arduous to animate than a png graphic. However Dryland has automated that process and we should have this time series shortly.

DMI offers a third ice thickness product based on the Los Alamos CICE model. That too comes as a png but requires a -45ยบ rotation to re-orient it.

Piomas has a fourth ice thickness product that is thoroughly analyzed by wipneus on that forum. Here I will simply concatenate, crop and resize those bimonthly gifs.

Here is a set of links that are useful for reaching the source sites:

https://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2018075.sir.gif

AMSR2 Hamburg sea ice concentration daily png
ftp://ftp-projects.cen.uni-hamburg.de/seaice/AMSR2/3.125km/Arc_20180316_res3.125.png
ftp://ftp-projects.cen.uni-hamburg.de/seaice/AMSR2/3.125km/Arc_20180316_res3.125_LARGE.png

OsiSaf ice drift daily 2018 03 14-03 16.png
http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2018&month=03&day=15&action=d%2B&prod=LR-Drift&area=NH&size=100%25

Hamburg SMOS ice thinness daily nc
https://icdc.cen.uni-hamburg.de/thredds/catalog/ftpthredds/smos_sea_ice_thickness/v3/catalog.html

Bremen SMOS ice thinness daily png
https://seaice.uni-bremen.de/data/smos/png/
https://seaice.uni-bremen.de/data/smos/png/20180316_hvnorth_rfi_l1c.png

DMI_SST ice thickness daily 2018 03 11.png
http://polarportal.dk/fileadmin/polarportal/sea/CICE_map_thick_LA_EN_20180316.png

DMI_SST ice surface temperature daily 2018 03 11.png
http://polarportal.dk/en/sea-ice-and-icebergs/sea-ice-temperature/#c8099
http://polarportal.dk/fileadmin/polarportal/sea/Map_IST_LA_EN_20180311.png

GFS/Nullschool wind/temperature/pressure 8x daily 5 days out 40 frames
https://earth.nullschool.net/#2018/03/15/1500Z/wind/isobaric/1000hPa/overlay=temp/orthographic=-45.00,83.00,1008/loc=0.100,83.690

Mercator Ocean daily + 9-day forecast
http://bulletin.mercator-ocean.fr/en/PSY4#2/62.6/-85.3

WorldView ice visible/infrared daily png
https://worldview.earthdata.nasa.gov/
https://worldview.earthdata.nasa.gov/?p=arctic&l=Coastlines,VIIRS_SNPP_Brightness_Temp_BandI5_Night

RASM-ESRL ice forecasts daily nc and gif
ftp://ftp1.esrl.noaa.gov/RASM-ESRL/ModelOutput
ftp://ftp1.esrl.noaa.gov/RASM-ESRL/ModelOutput/RASM-ESRL_4UAF_ICE_2018-03-16.nc
ftp://ftp1.esrl.noaa.gov/RASM-ESRL/ModelOutput/REB2.2018-03-16.nc
ftp://ftp1.esrl.noaa.gov/RASM-ESRL/ModelOutput/REB2_plots.2018-03-16.tar.gz

Cryosat ice thickness monthly
ftp://data.meereisportal.de/altim/sea_ice/product/north/cryosat2/cs2awi-v2.0/Latest/l3c_monthly/2018/
ftp://altim:altim@data.meereisportal.de/altim/sea_ice/product/north/cryosat2/cs2awi-v2.0/Latest/l3c_monthly/2018/l3c-awi-seaice-cryosat2-nrt-nh25kmEASE2-201802-fv2.0.nc

https://sites.google.com/site/arcticseaicegraphs/
« Last Edit: March 22, 2018, 02:20:35 PM by A-Team »

A-Team

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Re: The 2018 melting season
« Reply #7 on: March 21, 2018, 10:11:21 AM »
I am just staking out a final piece of real estate here on the first page to hold more year-to-date summary time series at a stable location, as it looks like the 3 slots above and the 12 graphics may not be quite enough.

This area will hold synchronized cross-silo products, typically 4 of the ones above in a 2x2 array. This allows various parameters to be more easily compared when the same date is shown at the same time, however this comes at the cost of half-resolution.

The placeholder below shows Piomas thickness combined with Ascat roughness for the last 16 days of March. Combinations with sea surface temperature, DMI thickness, and SMOS ice thinness will be posted in a bit. Shorter time frames can be posted frame by frame as gifs whereas longer time series have to be presented as movies to keep file size reasonable. That unfortunately involves lossy compression whereas the gifs retain all the data (if it is 8-bit or less).
« Last Edit: March 21, 2018, 10:42:43 AM by A-Team »

Alexander555

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Re: The 2018 melting season
« Reply #8 on: March 21, 2018, 10:30:38 AM »
That area in the north-east of Greenland, looks like it's still open water.

A-Team

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Re: The 2018 melting season
« Reply #9 on: March 21, 2018, 10:53:53 AM »
Quote
north-east of Greenland, looks like it's still open water.
No, it froze over almost immediately and has stayed that way. While this follows from persistent cold air temperatures, the observational trick is to look for stable cracks ... these can only form when there is ice. DTU Sentinel-1AB cloud-penetrating radar is probably the best way to look at the area. WorldView has been beset with clouds over this particular spot that resemble open water visually; the VIIRS image below is from March 14th. That's no accident because very thin ice with rifts still transmits ocean heat and vapor effectively to the air leading to clouds. Ascat is somewhat fooled because the new ice is still very smooth (ie black shows lack of roughness) but open water is much more flashy because of weather-borne salinity.

http://www.seaice.dk/
https://www.polarview.aq/arctic
https://www.polarview.aq/images/105_S1jpgfull/S1B_EW_GRDM_1SDH_20180321T112507_4868_N_1.final.jpg

Early 3.125 km UH AMSR2 sea ice concentration showed a patch of 'blue' but here you have to get the file open in something like Gimp with a non-contiguous color picker to pull out the true zero concentration regions (of open water).

About two-thirds of the new polynya ice is already headed out the Fram export door. The GFS wind forecast has this continuing, whereas the other third will be driven west in the direction of the Nares and CAA. The ice volume involved is well-captured by the negative region in wipneus's graph below.
« Last Edit: March 21, 2018, 11:11:54 PM by A-Team »

Pmt111500

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Re: The 2018 melting season
« Reply #10 on: March 21, 2018, 12:33:49 PM »
Moving my premature comment from the earlier thread here. Most, if not everything in it is still valid  ;)

"Last year 2017 I was quite strongly in the belief we'd have a new absolute minimum in the amount of Arctic Sea Ice, in all measures. But instead, 2017 had an early melt in the Southern Ocean. Thus, no idea what happens on the Arctic during summer 2018. At least not yet. Hoping the NA drift is strong enough to keep the Greenland freezing temperatures out of Southern Finland better than last three years."

We've had a very cold March here, so relying on foreign news about AGW.
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Daniel B.

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Re: The 2018 melting season
« Reply #11 on: March 21, 2018, 01:46:14 PM »
It has been a very cold March across much of the northern hemisphere.  How this affects Arctic sea ice this summer is unknown.

VeliAlbertKallio

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Re: The 2018 melting season
« Reply #12 on: March 21, 2018, 03:47:03 PM »
I doubt it affects much, we are still on some of the lowest volumes with fresh ice not having expelled as much salt as usual.

oren

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Re: The 2018 melting season
« Reply #13 on: March 21, 2018, 04:03:19 PM »
I think the first thing to expect of this melting season is an early melt-out of the Bering, and possibly record early inroads into the Chukchi.

Gray-Wolf

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Re: The 2018 melting season
« Reply #14 on: March 21, 2018, 04:18:24 PM »
Well I will certainly be looking at the number of high's that grace the basin this year esp. over the Atlantic side?
If low solar does lead to impacts in the propensity of HP's over the basin then maybe that would go some way to explaining why the record breaking years of 07', 2010, and 2012 were positioned where they were!

Last year we ha WACCy snow in west Siberia aiding with our protection of ice cover over the Atlantic side. This year we do not have that slow melting snow but are another year closer to solar Min.

It has been pretty clear on our side of the basin this last 3 weeks though?
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FishOutofWater

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Re: The 2018 melting season
« Reply #15 on: March 21, 2018, 04:52:12 PM »
The polar vortex split / sudden stratospheric warming brought on a very cold March in the eastern U.S. and western Europe but the northern hemisphere is warmer than normal. We need to be careful to discern the difference between the cold weather where most of us live and the warm weather in the northern hemisphere.

Note that the CFS v2 climate model forecasts continued ridging and warmer than normal temperatures over the Aleutians, Alaska, and the Beaufort and Chukchi seas through July. It now forecasts a stormy August in the central Arctic. The CFS model tends to over-forecast warm anomalies so don't expect the magnitude of the warm anomalies to be accurate. Moreover, the CFS model doesn't handle ocean mixing well so don't trust it to be any good at all in areas where there might be ocean mixing. I have chosen to post the forecast 850mb temperatures rather than the 2m near surface temperatures because they are a reflection of atmospheric dynamics. I don't trust the CFS model to deal with the sea ice and ocean mixing issues that strongly affect near surface temperatures. With those caveats, the CFS v2 model forecasts posted below make good sense as a continuation of the weather and ocean heat patterns that have been developing over the past 2 months.

July's forecast of higher than normal pressure on the Alaskan side of the pole could melt out large volumes of sea ice on the Pacific side of the Arctic while continuing transport out of the Fram strait. We'll see how this all plays out in September but these forecasts would put this year in contention for a record low in September.

bbr2314

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Re: The 2018 melting season
« Reply #16 on: March 21, 2018, 05:57:19 PM »
Anecdotally we already have 4" on the ground in the middle of the world's most prominent heat island directly on New York Harbor. Manhattan may see up to 12"+++ by the time the snow is finished in 18-24 hours. It is March 21st, and this has not happened since 1866.

This March has been unprecedented in terms of the practical WX in the NE US and I believe it is because we have temporarily reached a tipping point where dynamics favoring ice sheet expansion have now outweighed background heat, which is why NYC went from record warmest Feb to... this.

This relates back to the freezing season because I think it is directly related to what is happening in the Bering and Labrador/Baffin, where the ongoing flux from ice formation & destruction and the residual impact from albedo anomalies over the continents sufficient to create a near-standing atmospheric wave pattern.

We may see freak weather actually worsen into April, with snows maintained across populated regions as the current SWE anomalies show no signs of dropping just yet.

Again, relating back to the ice, the insane situation in the mid-latitudes should pump the Arctic full of heat transported from the ocean (...models are now showing the first major typhoon of the season as well). I think we are going to shortly see a dramatic opening of Bering + Chukchi and by 5/1 the front will be hundreds of miles more advanced than any other year in record-keeping. This will not be good for humans.

In good news, we may be at hemispheric SWE max? In bad news, if 1866 is not coincidental, it only takes about 40% more accumulated SWE vs. late 20th century normal to result in practical NHEM weather that mimics the end of the Little Ice Age. If another several years of ice decline lead to a continued increase in SWE, it isn't hard to imagine 1812-esque winters on the regular if we have already (possibly) regressed to the 1860s in terms of accumulated volume and are seeing the same weather as back then...

(...adding up possible coincidences, NYC's last period of five consecutive 30"+ winters was also in the 1860s, immediately when records started, unmatched since.... 2013-14 through today!)

« Last Edit: March 21, 2018, 06:05:48 PM by bbr2314 »

Archimid

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Re: The 2018 melting season
« Reply #17 on: March 21, 2018, 06:34:48 PM »
This March has been unprecedented in terms of the practical WX in the NE US and I believe it is because we have temporarily reached a tipping point where dynamics favoring ice sheet expansion have now outweighed background heat, which is why NYC went from record warmest Feb to... this.

 I think your are right that some of these WACCy dynamics are what some ice sheet expansions probably looked like, but I disagree that's in any way a sign that snow dynamics have already outweighed the background heat. They might eventually, but it has to be much worse than this.
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bbr2314

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Re: The 2018 melting season
« Reply #18 on: March 21, 2018, 06:46:26 PM »
This March has been unprecedented in terms of the practical WX in the NE US and I believe it is because we have temporarily reached a tipping point where dynamics favoring ice sheet expansion have now outweighed background heat, which is why NYC went from record warmest Feb to... this.

 I think your are right that some of these WACCy dynamics are what some ice sheet expansions probably looked like, but I disagree that's in any way a sign that snow dynamics have already outweighed the background heat. They might eventually, but it has to be much worse than this.
Correction: the snow dynamics *currently* outweigh background heat, I think by May and June they will fail, so you are definitely right.

The question is how much worse it has to get before May/June are off the table. With such an apparently dramatic response to ice loss as-is, another 10-20% wintertime decline with a corresponding increase like we have already seen in SWE is possibly sufficient, at that point we could be talking about seasonal max approaching 6,000 KM^3 of SWE, or 2X ~yr2000 avg.

If the summertime sea ice trends hold, ^ is feasible (IMO) by 2025. By 2030, we could end up with a planet that looks substantially different from today.

gerontocrat

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Re: The 2018 melting season
« Reply #19 on: March 21, 2018, 08:15:10 PM »

If the summertime sea ice trends hold, ^ is feasible (IMO) by 2025. By 2030, we could end up with a planet that looks substantially different from today.

There is a thread entitled "Ice-free Arctic" where people argue passionately about their view of the future of sea-ice and the climate generally. It is fascinating.

But this is the 2018 Melting Season Thread. I come here to see the amazing stuff from A-team and many others on what is happening and its influence on the melting season. Evidence and discussion on the the impact this year of the very high snowfall in the northern hemisphere this winter and spring is obviously part of the content for this thread.

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Neven

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Re: The 2018 melting season
« Reply #20 on: March 21, 2018, 08:54:18 PM »
I agree. Actual snow cover is extremely interesting, but updates on what it means in the long(er) run need to be posted elsewhere.
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FishOutofWater

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Re: The 2018 melting season
« Reply #21 on: March 21, 2018, 09:03:46 PM »
Judah Cohen has discussed how sudden stratospheric warmings are followed by 4 to 8 weeks cold stormy weather in the Northeast U.S. many times. You should read his blog.

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

As far as the upcoming weather I am not sure that I have much profound to discuss.  We are coming to the end of the stratosphere-troposphere coupling season.  I do think that the coupling is still active and that the current stratospheric PV displacement with a weakened PV center over western Siberia is related to the low heights and cold temperatures across Siberia.  Counterclockwise flow around the low height center both in the stratosphere and its reflection in the troposphere is resulting in a cold easterly flow of air out of Siberia and into Europe.

Cold temperatures and the very active storm track in the Eastern US is harder to explain.  There is some weak ridging in the polar stratosphere centered in and around Alaska that has a tropospheric reflection.  This would favor downstream troughing across the Eastern US.   Cold and possibly snowy weather is consistent with our new study that warm PCHs overwhelmingly favor more wintry weather in the Eastern US.  In addition there is a recent study by Zhang et al. (2016) that a displaced stratospheric PV towards Eurasia favors cold temperatures in eastern North America.  I expect this overall pattern across the NH to linger and weaken over time right up until the Final Warming when the stratospheric PV  disappears for the reminder of the spring and the summer.

It is my impression that once we move beyond the month of March spring weather/conditions advance fairly aggressively across the NH.  This manifests in a what I would describe as a collapse in continental snow cover during April and May.  Snow cover is currently relatively extensive both across North America and Eurasia with widespread cold temperatures, especially across Northern Eurasia.  It will be interesting to see how quickly the continents warm-up and how quickly snow cover recedes in the coming weeks and if possibly this spring, snow cover can buck recent trends.  One region I expect to heat up quickly regardless is the Western US but even there snow cover is extensive and maybe I will be wrong.


and after a long discussion

Recent research has shown that regional anomalies are important and the sea ice region most highly correlated with the winter AO is the Barents-Kara Seas region where low Arctic sea ice favors a negative winter AO and a cold Eurasia. Current warm Arctic/cold Eurasia pattern is nearly textbook and has been linked previously to low sea ice extent in the Barents-Kara Seas.  Continued below normal sea ice in this region may have contributed to more active WAFz/poleward heat transport that resulted in a stratospheric PV disruption.

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Re: The 2018 melting season
« Reply #22 on: March 21, 2018, 09:07:54 PM »
I think the first thing to expect of this melting season is an early melt-out of the Bering, and possibly record early inroads into the Chukchi.
How Bering Sea is ready for coming storms - here is sea ice area according to NSIDC on March 20 each year (2007 - 2018). I try to update the table over the next days - hope this is interesting to know.

Alexander555

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Re: The 2018 melting season
« Reply #23 on: March 21, 2018, 09:21:33 PM »
In some way it's a little strange to see 2012 as the highest number, and it had the lowest minimum the same time. And for this year it's the lowest number. Can somebody tell something about that 2011/2012 winter ?

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Re: The 2018 melting season
« Reply #24 on: March 21, 2018, 09:52:09 PM »
Seems the ice is acting up in Frobisher Bay an hour or two by snowmachine out of town. This is very early; it shouldn't be even much of a topic until mid to late May normally.

https://www.facebook.com/groups/iqaluitpublicservice/permalink/1682339141802056/
Quote
A hunter is warning people that some ice conditions are NOT safe out there especially Qairuliktuut area. It is different this year he says. Be very cautious and this is March.

Maps here. Warning: they're pretty, you might waste a lot of time reading them.
http://ihti.ca/eng/place-names/pn-seri.html

subgeometer

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Re: The 2018 melting season
« Reply #25 on: March 21, 2018, 10:50:51 PM »
This March has been unprecedented in terms of the practical WX in the NE US and I believe it is because we have temporarily reached a tipping point where dynamics favoring ice sheet expansion have now outweighed background heat, which is why NYC went from record warmest Feb to... this.

 I think your are right that some of these WACCy dynamics are what some ice sheet expansions probably looked like, but I disagree that's in any way a sign that snow dynamics have already outweighed the background heat. They might eventually, but it has to be much worse than this.

I have to agree. It can only be a superficial resemblance, given the warmth in the ocean and continental areas where snow doesn't fall or last on the ground. Heat transport eg in the form of rain can soon wipe out snow cover (as often happens in Australia in the Ice-age-glaciated Snowy mountains). The albedo of extra snow in spring and early summer makes a negative feedback but I can't see it outweighing the warming trend. Either way, we're in uncharted territory now

FishOutofWater

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Re: The 2018 melting season
« Reply #26 on: March 21, 2018, 10:57:38 PM »
Offshore winds have exported ice from the region of S Baffin island into the Labrador sea. Very stormy weather combined with intense blocking highs this winter has caused extensive mixing in the Labrador sea and that's put warm salty water in contact with ice on the margins of the open water of the Labrador sea. This situation may increase the rate of melting all the way into Hudson's bay because ice is moving through the passages.

Below is today's March 21, 2018 worldview Terra visible image showing open water and very thin ice around the south side of Baffin Island.

Note the above normal SSTs at the margins of the ice in the Labrador sea in yesterdays SST reanalysis map.

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Re: The 2018 melting season
« Reply #27 on: March 21, 2018, 11:06:14 PM »
It's Baffin and Barentsz that have heralded the max. Okhotsk is about to join the festivities:
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Re: The 2018 melting season
« Reply #28 on: March 21, 2018, 11:09:18 PM »
In eastern Massachusetts, I've seen 30CM of snow disappear in 48 hours.

I al so know that snowfall across the northern boreal forest won't particularly reduce albedo, just slow the start of biological spring. Im not sure that extra snow on the tundra will last that much longer.

Snow on the ice is the thing as that kicks up the albedo and has a better chance of persisting, and is what has helped save the ice the last few years. Will it this time?
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Re: The 2018 melting season
« Reply #29 on: March 21, 2018, 11:21:02 PM »
Ok, so who has a full set of actionable links to the best daily snow data sets?

I don't see a need for more generic bs about butterflies flapping their wings in the Amazon or snow cover of NH / land, sure it's all important but what we are looking for are snow depth maps at reasonable resolution, ie snow resting on Arctic Ocean sea ice as this is the AO melt season forum. In fact, better than canned maps is the netCDF data archive underlying the map, if we plan to compare approaches like we do with ice thickness.

Ok, so who has a full set of actionable links to the best daily AO albedo data sets?

Ok, so who has a full set of actionable links to the best daily AO melt pond data sets?

Ok, so who has a full set of actionable links to the best daily AO cloud data sets?
« Last Edit: March 22, 2018, 02:32:19 AM by A-Team »

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Re: The 2018 melting season
« Reply #30 on: March 22, 2018, 01:32:01 AM »
Correction: the snow dynamics *currently* outweigh background heat, I think by May and June they will fail, so you are definitely right.

The question is how much worse it has to get before May/June are off the table. With such an apparently dramatic response to ice loss as-is, another 10-20% wintertime decline with a corresponding increase like we have already seen in SWE is possibly sufficient, at that point we could be talking about seasonal max approaching 6,000 KM^3 of SWE, or 2X ~yr2000 avg.

If the summertime sea ice trends hold, ^ is feasible (IMO) by 2025. By 2030, we could end up with a planet that looks substantially different from today.
I would like to read your response to my analysis of Goose Bay snow dynamics history, in the thread I consider more appropriate for that discussion, NHEM snow cover.
https://forum.arctic-sea-ice.net/index.php/topic,103.msg146189.html#msg146189

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Re: The 2018 melting season
« Reply #31 on: March 22, 2018, 03:06:14 AM »
...

I don't see a need for more generic bs about butterflies flapping their wings in the Amazon...
Then how about a scientific discussion about rainmaking?

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Re: The 2018 melting season
« Reply #32 on: March 22, 2018, 03:22:16 AM »
Quote
Ok, so who has a full set of actionable links to the best daily AO albedo data sets?

I'm not sure this is what your asking for but I found this NASA sites that keeps Monthly Albedo maps and I think the data too.

https://neo.sci.gsfc.nasa.gov/view.php

Using images I got form that site I made the following animation. The animation is for March 2015-2016. The site seems to stop after February 2017.

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Re: The 2018 melting season
« Reply #33 on: March 22, 2018, 03:59:05 AM »
NOAA PSD's maproom has many useful maps including outgoing longwave radiation, but I'm not someone who downloads data and processes it myself. Here's where you can see many OLR maps:
https://www.esrl.noaa.gov/psd/map/clim/olr.shtml

Note the anomalous heat in the Barents sea. There's a lot of ocean heat near Svalbard that will start taking a toll on sea ice later this spring.

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Re: The 2018 melting season
« Reply #34 on: March 22, 2018, 06:22:20 AM »
I'm wondering if we need to primarily non-US sources because of how NOAA has been slagged.  That said, I'd expect something like a gridded albedo map might slip under the Trump admin's radar and might be locate-able.
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Re: The 2018 melting season
« Reply #35 on: March 22, 2018, 06:29:18 AM »
With daylight back, Worldview again moves up in the list of tools I use to watch what's going on.

So, to all of you, happy Equinox, and I give you a shot of the CAB just north of Svalbard, snagged from 3/21.

This area has been persistently open for most of a month, and the image I think gives us insight as to why.

The filament-like melting along the ice margin speaks to a very abrupt but significant temperature differential in the water.  This early, to see this, at this latitude I find very disturbing.

[Edit:  Checking Bathymetry, the region seems to correspond roughly to the edge of the Yermak Plateau, which leaves me wondering if its channeling warmer water from the Gulf Stream branch that is creating the hot spot just SE of Svalbard.]

[Edit2: Added Google Earth snip rotated to approximate the orientation from Worldview for comparison. I apologize for the relatively crude work.]

https://goo.gl/images/mrqB2b
« Last Edit: March 22, 2018, 06:57:11 AM by jdallen »
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Re: The 2018 melting season
« Reply #36 on: March 22, 2018, 07:07:48 AM »
Next montage - Western CAA including the Amundsen Gulf and the "uncorked" NW passage using worldview corrected reflectance bands 3-6-7.  Top is 2018, followed by 2017 on 3/22 and 2016 on the same date.  Banks Island is in the center of each frame.

I leave you to draw your own conclusions about comparative ice quality.
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Re: The 2018 melting season
« Reply #37 on: March 22, 2018, 02:17:53 PM »
In eastern Massachusetts, I've seen 30CM of snow disappear in 48 hours.

I al so know that snowfall across the northern boreal forest won't particularly reduce albedo, just slow the start of biological spring. Im not sure that extra snow on the tundra will last that much longer.

Snow on the ice is the thing as that kicks up the albedo and has a better chance of persisting, and is what has helped save the ice the last few years. Will it this time?

I don't think it is snow on ice exclusively. Last year an excess 4 million km2 of snow cover on land had quite an effect. According to certain citizen-scientist models, something like an extra million km2 of ice in September.

Hey: 4 million km2 is about the surface area of the entire European Union (actionable link: https://en.wikipedia.org/wiki/Geography_of_the_European_Union). That's a lot of extra albedo persisting during the critical thawing months.

Hey: how is snow cover coming out of the Equinox? Colder than the climatology, but a lot can change from now till May.

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Re: The 2018 melting season
« Reply #38 on: March 22, 2018, 03:17:31 PM »
I am not keen on reading six months of data-free speculation on what conditions prevail in the Arctic Ocean based on home-town weather.

Do we know of model and observational data sources that track daily albedo, melt pond formation (none yet), snow depth, liquid and ice water paths in clouds, rates of bottom ice melting, radiative heat fluxes etc? If so, which are the most reliable, how were they made and vetted, what are the links, how should we represent them as forum graphics?

Here is one source of both daily data and short-term forecasts but amongst our 1375 members we surely know of others:

ftp://ftp1.esrl.noaa.gov/RASM-ESRL/ModelOutput

Here is an integrated CryoSat2 resource for Feb 2018; the next release will be on April 3rd.

ftp://data.meereisportal.de/altim/sea_ice/product/north/cryosat2/cs2awi-v2.0/Latest/l3c_monthly/2018/

Thx to Fish for the link suggestion below -- I'll take a look though it may not be independent of the links above. Note by using second forum button in second icon row, you can display an image without downloading it.

Quote
NOAA PSD's maproom has many useful maps including outgoing longwave radiation, but I'm not someone who downloads data and processes it myself. Here's where you can see many OLR maps: https://www.esrl.noaa.gov/psd/map/clim/olr.shtml
« Last Edit: March 22, 2018, 05:46:53 PM by A-Team »

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Re: The 2018 melting season
« Reply #39 on: March 22, 2018, 03:27:20 PM »

I don't think it is snow on ice exclusively. Last year an excess 4 million km2 of snow cover on land had quite an effect. According to certain citizen-scientist models, something like an extra million km2 of ice in September.

Hey: 4 million km2 is about the surface area of the entire European Union (actionable link: https://en.wikipedia.org/wiki/Geography_of_the_European_Union). That's a lot of extra albedo persisting during the critical thawing months.

4 million km2 of excess snow cover.
persisting during the critical thawing months.
 
Where ? Exclusively on the treeless Russian Tundra and Canadian Barrens bordering the CAB? Or elsewhere as well?
For how long  ? Weeks? Months? Days? Presumably 4 million km2 of snow was not there one day and all gone the next?

There is a test bed for this - Hudson Bay. Shallow, low salinity, mostly landlocked with a continental climate, essentially a frozen inland lake for most of the year- (the Baltic is similar). If extra snow with greater longevity has the effect of significantly slowing sea ice melt, one should see it in the Bay. Last year we did not - the number of days with less than 5% of ice coverage went up.

But I can't find a simple multi-year snow analysis (extent by time) of that part of Canada to test any correlation. But this year may be another test?
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Re: The 2018 melting season
« Reply #40 on: March 22, 2018, 03:45:53 PM »


I don't think it is snow on ice exclusively. Last year an excess 4 million km2 of snow cover on land had quite an effect.

There are 3 major zones where your map shows positive snow anomalies: 1) Central Europe 2 ) US North, NorthEast, 3) The middle of the Middle Kingdom

I don't know about the last one, but the snow in the first two will be gone in 1-2 weeks. I'm in Central Europe, and two days ago it was all white around us, but as the Sun came up and temps moved above freezing, half of it is gone by today, and the rest will be gone in the next two days...

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Re: The 2018 melting season
« Reply #41 on: March 22, 2018, 04:47:29 PM »
This is an issue with the WACCy snows in that we get copious amounts but a lot of it to the south of regions normally seeing winter snow?

I've read reports on folk watching 30cm of snow go over a two day period as 'normal' temps return.

that is returning to 'normal' takes the snow but we will also see WAA continue to push north across regions bringing days above the norm and rapid melt?

Last low solar saw some pretty big heat domes establish across inner continental areas. If it was low solar that helped these situations maintain then we know we have 3 or 4 years of similar now in front of us coupled with the renewed spurt in background warming.

I have great concerns over the changes the next few years might bring us from a final destabilisation of the 'hillocks' across Yamal to our first blue Ocean events ( and the wrench that would stuff into N. Hemisphere circulation).

Our first test will be the melt ponding over the Atlantic side of the basin this year? If the last vestiges of 'northern blocking' over the Atlantic keep skies clear over Barentsz/Kara then we will see an uptick in melt ponding ( if Greenland's high joins in the fun and adds to a beaufort high then we might be looking more toward a 'perfect melt storm' synoptic setting up?)
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Re: The 2018 melting season
« Reply #42 on: March 22, 2018, 05:10:14 PM »
The heavy March snows in the western U.S. will tend to lessen the severity of heat domes that build up in the U.S. mid-continent region. When the mountains in the west dry out early in drought years dry heat can build up at the 10,000 foot level and above then drift over the mid-continent. The result can be absolutely brutal heat. These March snows will also tend to lessen wildfire intensity. That's good news for ice in Greenland that might be affected by soot.

The snow in the U.S. and Europe is good news but don't expect it to have much effect on the sea ice because it won't stick around for long. Sudden stratospheric warmings like the one in mid-February appear to be an effective way of cooling the atmosphere for a month or two, but the heat is already building up in central Asia. Expect a rapid warm up and faster than normal loss of snow cover in April and May.

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Re: The 2018 melting season
« Reply #43 on: March 22, 2018, 05:30:59 PM »
Here is the thing ... yes there were positive anomalies, and yes sea ice didn't melt as much as we feared it could, but I think it is a serious mistake to treat the land Snow cover anomalies as causal.  Thermal transfer from air to ice is trivial compared to insolation and water.  Air temperature is buffered by water as well.

Albedo over the oceans. Water temperature. Those are the main factors.
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Re: The 2018 melting season
« Reply #44 on: March 22, 2018, 05:45:44 PM »
I am not keen on reading six months of data-free speculation on what conditions prevail in the Arctic Ocean based on home-town weather.
I speculate based upon Four'easters here in Boston that the Gulf Stream has switched to hugging the coast and it is going to play havoc with the Greenland Ice Sheet.

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Re: The 2018 melting season
« Reply #45 on: March 22, 2018, 05:50:39 PM »
Quote
havoc with the Greenland Ice Sheet.
The long-running Greenland melt forum is located elsewhere.

Quote
Here is the thing ... mistake to treat the land Snow cover anomalies as causal.  Thermal transfer from air to ice is trivial compared to insolation and water.  Albedo over the oceans. Water temperature. Those are the main factors.

Right. The snow pack over Arctic sea ice will be increasing to mid-calf thickness in the Chukchi but remains minimal overall according to RASM ESRL. We won't have a refresh on snow density until early April. Albedo and insolation effects can only kick in ocean-wide after the pole hole is gone on March 29th (Modis Terra can image the entire Arctic). There are no melt ponds at this point.
« Last Edit: March 22, 2018, 06:12:52 PM by A-Team »

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Re: The 2018 melting season
« Reply #46 on: March 22, 2018, 06:01:42 PM »
Quote
havoc with the Greenland Ice Sheet.
The long-running Greenland melt forum is located elsewhere.
I'm betting on this year.  Not so much Greenland, as the Gulf Stream.  That might even reduce the heat in the North Atlantic -- though I think there is enough heat to go around.

The Atlantic is changing -- and I don't buy into the theory that the overturning will stop.  Much more likely is for the warm water to pile up and force its way into the Arctic -- just as it has been doing.


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Re: The 2018 melting season
« Reply #47 on: March 22, 2018, 06:06:12 PM »


I don't think it is snow on ice exclusively. Last year an excess 4 million km2 of snow cover on land had quite an effect.

There are 3 major zones where your map shows positive snow anomalies: 1) Central Europe 2 ) US North, NorthEast, 3) The middle of the Middle Kingdom

I don't know about the last one, but the snow in the first two will be gone in 1-2 weeks. I'm in Central Europe, and two days ago it was all white around us, but as the Sun came up and temps moved above freezing, half of it is gone by today, and the rest will be gone in the next two days...

I have not checked the weather for Central Europe in the next two days, but the U.S. north and northeast is expecting more snowfall. 

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Re: The 2018 melting season
« Reply #48 on: March 22, 2018, 06:22:21 PM »
Hello newcomers: in years past, 'The 2018 melting season' has just been a short name for what was actually 'The 2018 Arctic Ocean sea ice melting season' forum, just like the freeze season forum. Note this forum sits in a sub-directory of the Arctic Sea Ice collection.

Do we need to open a separate forum this year called the 'The 2018 Arctic Ocean sea ice melting season'? Otherwise we are going to have thousands and thousands of off-topic posts here by September.

I for one have zero interest in home-baked opinions not accompanied by outside factual support.  Do you really know anything about Atlantic Water intrusion into the Svalbard region beyond what is already beautifully imaged and forecast at Mercator Ocean? Where could this knowledge possibly be coming from? 

It's not what you know (or pretend to know) but how you know it. Attach a link, an image, a journal DOI, cite your post-PhD oceanographic research, something ... otherwise go to one of over 1850 chat room forums to vent personal feelings about how climate change will play out.

People are certainly welcome to their own opinions but not to their own facts (or lack thereof).
« Last Edit: March 22, 2018, 06:59:03 PM by A-Team »

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Re: The 2018 melting season
« Reply #49 on: March 22, 2018, 06:29:26 PM »
Hello newcomers: in years past, 'The 2018 melting season' has just been a short name for what was actually 'The 2018 Arctic Ocean sea ice melting season' forum, just like the freeze season forum.

Do we need to open a separate forum this year called the 'The 2018 Arctic Ocean sea ice melting season'? Otherwise we are going to have thousands and thousands of off-topic posts by September.
We have threads called "Ice-Free Arctic", "Northern Hemisphere Snow Cover". I guess Neven may have to get out the snips. Having one's words of wisdom castrated is a painful experience.
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