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Messages - bbr2314

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1
Arctic sea ice / Re: The 2017/2018 freezing season
« on: January 15, 2018, 08:36:19 AM »
I dont think that these NH snow charts are very useful. Snow in E-Europe, or mid-USA does not matter, it melts in March quickly anyway. What does matter is snow on arctic ice - at least that is what last summer proved. If there is lots of snow on some thin ice it can still insulate it for quite a while and protect it long enough. However, if the thin arctic ice is not protected by much snow - then all bets are off for next summer. So we should know how much snow is on arctic ice, and as far as I know we dont know that
...this is very incorrect.

Snow in southern latitudes does a much better job of reflecting sunlight back into space and reducing overall heat anomalies vs. snow in sunless high-latitudes (that are probably covered anyways).

Additionally, snowfall over thin ice can do a better job of insulating heat underneath, paradoxically creating warmer conditions if heavy snows occur when initial refreeze completes.

2
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: January 01, 2018, 06:21:43 PM »
. Because at the moment North America is absolutely in the freezer, and NYC may see its coldest two-week period since 1977 (or before).

Last January was just the opposite:North America very warm, while Europe getting the coldest January since 1987! This year Europe is very warm, likely the warmest since the springlike winter of 2007, and the USA is freezing.
I wonder if these extremes are the sign of an imminent regime shift in midlatitude winter weather due to Arctic changes: nonlinear systems often have huge oscillations before settling into a new mode

I think there was a state change sometime in the early 2000s that finalized in the 09-10 Nino. The question is how long it takes to get to Point B?

NYC's 15-yr median snowfall increased from 15" in 08-09 to 40.0" by 16-17. It is higher than at any point in history back to 1883-84.

Perhaps the two confounding factors that have been most responsible are 1) Greenland shifting to consistent and generally increasing annual net loss and 2) Worsening fall + wintertime ice anomalies in the CAB/Peripheral Seas which are allowing increasing predominance of standing wave patterns in the high and mid latitudes down below.

If this is the case, and both factors continue on their current trajectory, we should see snowfall continue to rise across the NE seaboard. The question is how quickly amounts jump when we get to Point B and whether that precludes re-glaciation (I know, I know, everyone yells at me about this, but the snowfall data over the past year has been surprising to say the least).

Perhaps the next big Nino will be sufficient to push us over the edge? Changes seemed to accelerate very dramatically after 09-10, maybe we are still in the afterglow of the 15-16 event.

Finally: the Ewing-Donn Theory was thoroughly rejected previously. But what if the breakdown of CAB/peripheral sea icepack in wintertime is sufficient to generate worsening standing wave patterns that propagate for longer and longer periods until parts of the NHEM do end up in perpetual winter, when combined with the cold freshwater flux from Greenland/mounting continental snow totals? The theory may not work when we consider an active pattern even resembling the mess we currently see today, however, the albedo feedbacks could be more prone to runaway craziness if atmospheric angular momentum decreases to the point where weather is "stuck" for many months on end.

3
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: January 01, 2018, 06:13:06 PM »
The fundamental oscillation is that of the polar front.  Since there are 4-6 waves along the front, if it is cold on the US east coast (trough), there will tend to be a ridge over Europe and the US west coast.  Warming oceans tend to lock the waves along the polar front in place.
Indeed. Perhaps this is a reflection of oscillating or varying ice cover in Bering/Chuckchi vs. Kara/Barentz?

I.E., (versus normal), negative anomalies in both seas favor negative anomalies in both continents, negative in one vs. normal in the other = another variation, etc?

Of course, ^ are subject to changes, but it would make sense that gaping areas of ice-free waters in the peripheral seas are the perfect heat reservoirs to encourage stability/standing wave patterns in the mid-latitudes.

4
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: January 01, 2018, 02:30:39 PM »
On the above note, it is not often numbers like this appear off the NE seaboard. I believe the last time we had substantive sea ice form was in February of 2015, and before that, probably January of 1994, and a few times in the 80s/70s. But for a good twenty years, it was almost entirely absent.

https://www.nodc.noaa.gov/dsdt/cwtg/catl.html

Again, this seems highly suspect to be related to what has happened in the Chuchki/Barentz, as well as the early freeze of Hudson Bay and the changes in the North Atlantic. In fact, while the shoreline is now freezing, the pool of warm water off the seaboard has only worsened on an annual basis since the El Nino of 2009-10 (perhaps this was when Greenland passed a tipping point in terms of precip + mass loss impacting oceanic circulation?).

In any case, by 1/10, it seems likely that much of the Northeast seaboard will be entirely iced in, possibly even outranking February of 2015. The Hudson in NYC may even be walkable from Jersey to Manhattan, and I am unaware of the last time that occurred, maybe 1977? If not then, probably 1917-18 or February of 1933.

5
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: January 01, 2018, 02:15:24 PM »
It should also be considered that the record New Years low comes in spite of very good coverage across Hudson Bay. The Maritimes are lacking slightly, but Hudson Bay's refreeze happened early and vigorously this year relative to recent normals. The quick gains in the low-latitudes are now being countered by the heat at depth that is increasingly predominating across the peripheral seas.

It is important to distinguish the impacts resulting from having lots of relatively low-latitude ice, and a dearth of high-latitude ice, vs. other sides of the coin. Because at the moment North America is absolutely in the freezer, and NYC may see its coldest two-week period since 1977 (or before). Obviously Asia/Europe are mostly warm, but if Hudson Bay & the Maritimes/Sea of Okhotsk continue their seeming increase in freezing momentum into the future (especially relative to the rest of the Arctic), the downstream impacts promise to be substantially more vigorous than if melting had been uniform. In fact, it would seem to be a probable driving cause behind worsening Arctic Amplification (if the "cyrosphere" has a gaping hole in the middle + a periphery that is increasingly separated at some part of the year, then it isn't a unified cryosphere, and you end up with roaming Sandy-esque lows in places they formerly did not exist).

6
Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 03, 2017, 01:14:47 AM »
Despite the warmth, Frobisher Bay is freezing up a bit today. There's little blobs of ice out in the bay, with a cap of snow on each.

Well that went quickly.

Yesterday:


Today:


What happens if at some point we end up with MYI in Okhotsk + HB and only FYI in the CAB?

How would you get MYI in Hudson Bay? Temperatures are higher than historical, and historically there was none.

You would need a cooler repeat of summer 2017, where snow is retained along much of the shoreline til the end of June or July. If we see the current snowfall feedback make much more progress, this will not be unfeasible (explaining why 2017 was so anomalously snowy).

Even though extent has gone into lag mode, volume continues to perform phenomenally and historically well:





Hudson Bay SSTs are largely a function of whether the surrounding land mass is snow covered. When it is, ice forms and it becomes a source for cold air. When it isn't, the ice is unprotected and mostly melts out (exception being parts of Foxe Basin).

If Hudson Bay begins behaving more like Foxe Basin -- which is much more protected, but also only a hair to the north -- it is not unfeasible for MYI to begin accumulating in the most protected parts. Historically, this must have occurred, the question is, how marginal were the conditions, and does our worsening open water/moisture flux conundrum make it more likely?

7
Arctic sea ice / Re: The 2017/2018 freezing season
« on: December 01, 2017, 09:20:06 PM »
Hudson Bay's refreeze over the last week has been one of the earliest on record over the past twenty years it seems. Should be mostly frozen by 12/5-12/10!

Per the ice atlas, that's about normal -- of course we haven't had normal in a while:
In late October, the ice begins to form along the northwestern shores of the Bay. Some years there may also be a simultaneous development in the cold waters near Foxe Channel. In November, the ice thickens as prevailing winds move it east and southeast. In December the Bay becomes covered with thickening first-year ice.

It's well above normal in Iqaluit through the end of the forecast period, with the lows being warmer than the normal high, and lots of snow.

Reanalyzer shows an angry hot Canadian Arctic. The only exception is the West side of Hudson Bay, which is slightly cooler (and outright cold inland).

I just noticed that the cci-reanalyzer doesn't have a border between NWT and Nunavut. They're up to date on the climate, but not the politics, it seems ;)

Actually, I believe Hudson Bay is one of the only peripheral regions that has *not* experienced a catastrophic delay in the onset of freezing in recent years -- things have remained fairly steady, and its endurance has also been about constant.

With increased heat flux in autumn, it might be worth considering differentiating between ice regions that were always multi-yr vs. first year. Obviously large swaths of the Arctic are now transitioning, but outside of Foxe Basin, Hudson Bay has always been entirely FYI (to my knowledge).

The impact of the additional summertime heat could be for more convective autumnal weather which has a net impact of allowing earlier refreeze, as the dissipation of accumulated heat occurs faster thanks to the massive LPs that have been forming. This does nothing to alleviate the burden on the multi-yr ice (in fact, destroying it through winds + waves), but it does allow FYI to form faster when temperatures get sufficiently cold enough. In the case of HB this year, the refreeze has been more rapid than normal in terms of its onset to where it is now (check out the last week on EOSDIS!).

This would also help explain why the Sea of Okhotsk has also seen record numbers in recent yrs. It is not each and every year of course, but these distinctions are worth considering.

What happens if at some point we end up with MYI in Okhotsk + HB and only FYI in the CAB?

8
Arctic sea ice / Re: The 2017/2018 freezing season
« on: November 29, 2017, 08:13:06 AM »
Hudson Bay's refreeze over the last week has been one of the earliest on record over the past twenty years it seems. Should be mostly frozen by 12/5-12/10!

9
Arctic sea ice / Re: The 2017/2018 freezing season
« on: September 23, 2017, 08:13:09 PM »
Snowcover should build very rapidly through early October. GFS/CMS/EURO all show a massive area of anomalously cold temps building across most of Eurasia by D10 corresponding to generous snowfalls across much of Siberia and the Central Asian Plateau. We will also see the first falls across much of Alaska, the NW Territories/Yukon, and Quebec, with possible lasting duration across the latter.

I think it is important to reflect on the divergent signals that have emerged at the same time over the past few years. Namely, Greenland is now *increasing* in ice mass, with albedo massively increased in year over year comparisons due to the tremendous and ongoing snowfalls that have been occurring. In fact I believe we have probably still seen the same or more melt than is normally seen, however, the sheer frequency of massive snowfalls has been sufficient (IMO) to overwhelm -- i.e., the same thing resulting in Houston's floods is now seemingly occurring up north in a format that is white and not wet. This at the same time that global sea ice is once again setting a record-low maximum...!

My suspicion is that this massively unexpected positive albedo trend over Greenland was directly responsible for the surprisingly meek melt season. In fact, it is the most obviously glaring unexpected happening of the past 12 months that it is quite likely to have been the cause.

The question is what happens moving forward? Snowcover is currently somewhat above average, that should increase to well above average as we move into October, both according to the models and as indicated by recent changing climatology. Besides Greenland's increase in mass, the Himalayas have also stayed overwhelmingly white through the summer. The combination of these albedo anomalies and the record-warm Arctic ocean waters should yield more opportunities for early season snowfall (IMO) and we may see record #s.






10
Arctic sea ice / Re: The 2017 melting season
« on: August 13, 2017, 09:03:28 PM »
NHEM snow season about to kick into gear way earlier than normal, substantial falls expected to begin across portions of southern Russia by D10, wonder how things look by 9/10...


11
Arctic sea ice / Re: The 2017 melting season
« on: August 06, 2017, 09:12:41 PM »
It seems that NHEM snowcover may soon begin its autumnal ascendance; by D10 the GFS and CMC have extensive falls over Alaska, The Yukon, and Northeastern Siberia. These probably won't endure for too long, but a definite sign that things are starting to cool off...



However reliable the Canadian snowcover maps are, the graphs are showing extent remaining well above normal (relatively speaking).




12
Arctic sea ice / Re: The 2017 melting season
« on: August 05, 2017, 07:20:46 PM »
it would produce 27% increase of wave height - to 4+ meter waves (i calculated for 12h duration; longer duration would give up to 35%).

Here's the current WWIII forecast for this evening (UTC):

http://GreatWhiteCon.info/2017/08/facts-about-the-arctic-in-august-2017/#comment-222642

2.5 meters seems to be nearer the mark. Peak period 7-8 seconds.

That is going to do a *horrific* number on the ice and explains the TOPAZ forecast. The Pacific edge of the pack is going to be retreating by tens of miles per day, and even the relatively thick ice is now vanishing (i.e. check Beaufort satellite imagery past few days).

The above will work in tandem with the already-decrepit first yr ice across the Russian/Atlantic periphery to result in continuing major losses. With the amount of heat on the Pacific side, the question is how far the front advances before refreeze... and with very little thick ice in the way of those waves, we may have to wait until September.

This means it may not take a GAC on-par with 2012's to achieve the same effect, simply because the remaining ice quality vs. 2012 is mostly substantially worse.

13
Arctic sea ice / Re: The 2017 melting season
« on: August 05, 2017, 06:44:55 PM »
If TOPAZ is correct, we see a continuing cliff through the 13th, and with the amount of thin ice remaining, that seems likely to continue through the end of the month...


14
Arctic sea ice / Re: The 2017 melting season
« on: August 02, 2017, 04:49:10 AM »
7-31 to 8-1 on UBremen must have easily been 200K if not 300K KM2 area. WOW. The day over day difference is enormous and in the Beaufort a massive chunk of extent simply vanished!

15
Arctic sea ice / Re: The 2017 melting season
« on: July 22, 2017, 09:08:22 PM »
Both NSIDC and IJIS extent have moved into 2nd place. And the graphic below indicates that at least NSIDC may/will even take 1st place from 2011 (which started to flatten out the last week of July), and stay there until the first week in August, when the GAC took 2012 on its major downward excursion.
What good is extent if thickness is incomparable to 2012?
http://sites.uci.edu/zlabe/files/2017/07/sit_PIOMAS_mask_June17.gif
What's left over is very thin. 95% of 2 meter ice is gone now, 99% of the 3,4 and 5 meter ice too.
I agree. It is very bleak. 2012 was still melting through multi-yr ice of 2-3M thickness, 2017 is going to be feasting on 1-1.5M ice that hasn't seen a summer yet. The losses vs. all other years over the next 30 days are going to mount to absurd levels due to the volume deficit which is now going to manifest in continued area/extent drops. It's as if nearly the entire Arctic was covered in the ice of Hudson Bay.

16
Arctic sea ice / Re: 2017 sea ice area and extent data
« on: July 22, 2017, 09:06:28 PM »
Big drops, finally Laptev is seriously getting rid of all that ice. Greenland Sea extent continues to go down.

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data
Date: 2017-07-21 12:00  Values in 1000 km^2

Extent (value, one day change, anomaly):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
  4419.2   +6.6   -11.1    462.4  -25.9  -364.9    440.2  -75.3  -129.4
               Kara Sea             Barents Sea           Greenland Sea
   144.6  -25.7  -415.9     57.8   -5.1  -110.1    225.0  -53.1  -185.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
   314.6  -10.6   -39.7      6.8   -1.6    +6.8    175.2   -1.2  -141.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   577.2  +14.2   -83.6    267.1  +28.4  -120.0    125.1   -2.6  -207.4
             Bering Sea          Sea of Okhotsk                   Lakes
     4.2   -1.3    -1.2     20.3   +1.0   +20.3    172.5   +5.5   +43.3
          Other regions       Total (ex. lakes)
     2.9   +0.0    +2.9   7242.6 -152.1 -1780.1

Area (value, one day change, anomaly):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
  3463.6  -86.6  -249.5    233.5  -10.2  -303.0    242.5  -35.1  -114.6
               Kara Sea             Barents Sea           Greenland Sea
    70.4  -15.7  -271.1     16.5   -2.6   -57.4    117.0   -2.2   -80.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
   136.1  -10.0   -20.9      1.7   -0.9    +1.7     66.1   +1.6   -72.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
   379.0  -12.6   -63.4    153.9   +5.5   -94.6     51.1   +0.9  -147.5
             Bering Sea          Sea of Okhotsk                   Lakes
     0.7   -0.3    -0.7      4.4   +0.1    +4.4     93.3   -1.4   +36.4
          Other regions       Total (ex. lakes)
     2.2   -0.1    +2.2   4938.7 -168.2 -1466.9


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.
:o

If this keeps up we could be at 4M KM2 area by 8/1!

I think it must be emphasized that despite the benign "conditions" in the Arctic, melt has kept up or surpassed all yrs on record.

The question that must then be asked, is why? If we have been having extraordinary extent/area losses, then what explains that? It is the horrible volume #s, which are artificially bumped by the "false" +++ anomalies along the Atlantic edge (PIOMAS).

I don't think many have truly grasped what happened between this past winter and this year; the Arctic went from an environment that produced swirly cones of thick, layered multi-yr ice, to a place where ice that survived the previous season barely made it into the next one, while 1-1.5M of bad-quality ice formed alongside it, some of it not even making it through the winter.

Most of the ice over the Arctic Ocean is legitimately the equivalent of what has already melted out over Hudson Bay, which means the losses are going to continue in full form for at least the next month. That will translate into a wide gap with 2012 by 8/1, and a yawning one by 8/15 (IMO).

While 2012 had the GAC, 2017 has a thin sheet of ice that can't even endure colder than normal weather without losing 170K area per day. LOL!

17
Arctic sea ice / Re: The 2017 melting season
« on: July 22, 2017, 12:45:44 AM »
NSIDC SIE  x 106 km2

2017,    07,  17,      7.765
2017,    07,  18,      7.640       Down 125k
2017,    07,  19,      7.518       Down 122k
2017,    07,  20,      7.395       Down 123k

 Some have commented that cooler air is on the way for many parts of the Arctic. Still, most surface air will remain above freezing, even if slightly, and insolation will continue either way.
Looks like a little wave activity starting to kick up here and there today and over the next few days. This may redistribute enough warm water to escalate the attack on the sea ice.

The coldest temps are on the Siberian/Pacific side where the ice is thin and SSTs will melt much or all of it out, whereas warm winds are blowing north of Greenland and Ellesmere Island most of the week according to ECMWF/Windy, as well as along the Atlantic fringe. For ice retention it would be better if the core of the cold were between the Pole and Greenland/CAA.

And the NH tropical cyclone season is cranking up, so we'll likely soon see one tracking into the Polar region with attendant warmth and moisture
The first moisture plume from the epic impending WPAC typhoon is visible here @hr198 of the 18z GFS as it tracks over the Beaufort/CAB. At that time the GFS is also flinging another typhoon north towards the Arctic to join the fray. The event is already beginning in its formation, and as we continue seeing century drops the next few days (or near century drops), we are probably likely to push back into the 100K+++ range for at least a period as the below unfolds.

That is a *serious* amount of tropical moisture and it is going to fall across and impact the Pacific/Beaufort pack, which is in the worst condition ever and is already giving way to the tune of tens/hundreds of K KM2 per day.



Look at all that rain -- and it isn't light, either!




18
Arctic sea ice / Re: IJIS
« on: July 21, 2017, 08:08:32 AM »
7/20

7.194, -96K.

If this keeps up 2017 takes lead tomorrow or next day and then begins putting distance with 2012, which is still at 6.03M as of 8/2.

That means 2017 has 13 days to melt 1.164 million KM2 of ice in order to be ahead of 2012 by the end of its relative plateau, requiring an average melt of 89K KM2 or greater per day.

Given we are coming off over a week of century breaks and almost matched that today, 2017 seems poised to put over 100K KM2 of distance between it and 2012 come 8/2 (IMO).

If 2017 keeps up its numeric rate of melt for the last 7 days, it will be at just over 5.8M KM2 come 8/2, for what it's worth (or over 200K below 2012).

2012 had some huge drops in the coming week (including a double century break mentioned earlier), but then a handful of slow days, before seriously dropping off during GAC-2012. But given that there is still some 'piggy bank' ice, like TT says, and the decrease has picked up again in other datasets, 2017 might indeed be able to keep pace with 2012 until the end of the month, and then with 2007 during August. There might be another couple of century breaks in the works in the next 10 days.

Which would be quite amazing, given that the weather hasn't been anything like 2012, let alone 2007. Evidence, of course, that PIOMAS has it right with regards to ice being thin.
I wonder whether this impending setup will negate the need for an exact equivalent of a GAC.

Models are now showing a massive typhoon developing and persisting in the eastern West Pacific for at least the next ten days. It flings up several different spigots of moisture but the largest arrives in the Arctic by D7 and is visible surrounding the 981mb low in the frame below.

Such an event will be accompanied by substantial liquid precipitation and heat, and the ramifications are likely to be quite severe (IMO).


19
Arctic sea ice / Re: IJIS
« on: July 21, 2017, 05:28:15 AM »
IJIS:

7,290,578 km2(July 19, 2017)down 86,899 km2 and 3rd lowest measured for the date.
7/20

7.194, -96K.

If this keeps up 2017 takes lead tomorrow or next day and then begins putting distance with 2012, which is still at 6.03M as of 8/2.

That means 2017 has 13 days to melt 1.164 million KM2 of ice in order to be ahead of 2012 by the end of its relative plateau, requiring an average melt of 89K KM2 or greater per day.

Given we are coming off over a week of century breaks and almost matched that today, 2017 seems poised to put over 100K KM2 of distance between it and 2012 come 8/2 (IMO).

If 2017 keeps up its numeric rate of melt for the last 7 days, it will be at just over 5.8M KM2 come 8/2, for what it's worth (or over 200K below 2012).

20
Arctic sea ice / Re: The 2017 melting season
« on: July 20, 2017, 10:05:01 PM »
Also:

The typhoons are going to inject a huge plume of moisture into the Arctic. The GFS shows a huge area of the Arctic receiving over an inch of liquid precipitation (some falls as snow, but vast majority as rain).

I wonder whether this will act to rapidly melt much of the remaining FYI along the Russian/Pacific/Beaufort fronts -- common logic would say that combining 1" of liquid QPF with winds and waves results in dramatic losses.



The 993MB low near Wrangel is a direct descendant of one of the typhoons and appears on both GFS/CMC. The moisture punch will be very powerful.


21
Arctic sea ice / Re: The 2017 melting season
« on: July 20, 2017, 09:58:37 PM »
I believe we are going to see some big changes in PIOMAS from 7/15-8/15 that put 2017 far and ahead of all other years in terms of melt.

Comparing the charts between this time last year and today, 2017 has a substantially larger portion of its remaining area/extent that is far thinner than 2016, especially north of 80 degrees.

The main differences between last year and this year so far have been substantially less ice on the Russian/main Pacific front in 2017, slightly more in Beaufort, and substantially more on the Atlantic.

The Atlantic ice is going to melt out hook or crook and the forecasts from HYCOM et al over the next week+ show this is only going to accelerate. In fact, 2017 is going to begin closing rapidly on 2016 in terms of Atlantic area/extent.

As the Pacific/Russian fronts continue falling towards the CAB at an alarming rate (worse than any year before), this is going to setup a continued area/extent/volume cliff that persists through August and well into September, a la 2012 but likely worse.

The interesting point to consider is whether PIOMAS is overestimating current volume along the Atlantic, and what happens when the ice that it thinks is there melts out completely (as is likely to happen by 9/15 in totality, but by 8/15 in earnest). The ice there is certainly present, but is it actually all that anomalously large in thickness? We will soon find out.

If this all melts out as history would indicate it will, the "false" positive perceived by PIOMAS will result in a relative anomalous drop compared to 2012, as that is the only region holding 2017's #s out of the gutter they had previously been relegated within. Accounting for this, an area/extent record also seems much more plausible when you consider that the current state of 2017 vs. 2012 may be overestimated in 2012's favor.

With AMSR2 probably set to drop below 5M KM2 within the next two days, we could easily drop below 2M KM2 by 9/1, setting the stage for a minimum somewhere between 1.5-1.8KM2 (IMO).

22
Arctic sea ice / Re: IJIS
« on: July 17, 2017, 03:42:20 AM »
<snip;N.>
...

The topic is IJIS!
I thought it was ISIS?? Is IJIS a Japanese offshoot?  :o

23
Arctic sea ice / Re: The 2017 melting season
« on: July 13, 2017, 08:11:36 PM »
       It seems to me that at some point in past melt seasons, Greenland and the CAA served as a sort of backstop for compaction. This area usually stayed protected from SST's longer, too. With Nares open and likely the CAA itself soon to be, not only will the "Garlic Press" be open, allowing for loss of ice from the CAB, but there is also bound to be less compaction. This will make a huge difference in the vulnerability of the ice late in the season.
        An army that is loosing a battle falls back and regroups in order to make best use of it's strength. The ice, though very much unwittingly, has done just the same in past seasons, allowing it to hold out longer. How will the late season be affected if the ice can't compact as well, perhaps even dispersing more? If the winds and currents try to compact it elsewhere, SST's might be a problem, at least for a moment.
I would think the Arctic fights back with an even bigger block of ice, i.e., Greenland. It has something like 145X the volume.

The melt season in Greenland has so far been muted by persistent cold and the albedo gains accumulated over the previous twelve months, but the question is whether that will continue through October with an Arctic ice pack that shrinks to its smallest area ever (IMO). A la 2012, this should focus more heat onto Greenland as the area of highest albedo continues to dwindle in relative size.

I anticipate a dramatic increase in Greenland melt as we enter August -> September -> October but we shall see if it actually happens. With the amount of moisture that will likely be available, winter's firm return in the far north + interior could easily be offset by vast plumes of coastal wetness that decimate the pack within a few hundred miles of shoreline. That may mean that while the sheer area of Greenland that sees melt remains lower than normal, the discharge could still increase to near-record or record levels.

24
Arctic sea ice / Re: The 2017 melting season
« on: July 03, 2017, 08:57:02 PM »
Temp map above:

Jeezus. . .

Satellite view from Beaufort/Chukchi and into the CAB regions shows the highest amount of melt ponding that I have ever seen, ever.  I mean, look how dark blue the ice is now!

https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Graticule,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2017-07-03&z=3&v=-2080593.446460003,-278032.1484467292,-442193.44646000303,531951.8515532708

Boys (and girls)  I think we just hit the cliff. . .
"Relatively cool" in Central Arctic = still just around freezing at the coldest, with intervals of warmth persisting... and the latest satellite imagery as noted above portends a continuing and worsening nosedive in extent/area #s. Combined with the imminent melt-out of the Atlantic positive anomalies on PIOMAS, I would imagine that 2017 begins putting sizable distance between itself and 2012 in terms of volume, area, and extent numbers, especially as we pass 7/15. I expect the gap will begin yawning as much as it was earlier this year by the end of August, but who knows.

25
Arctic sea ice / Re: The 2017 melting season
« on: June 26, 2017, 05:05:38 PM »
Slater's #s for August have taken a nosedive in the past few days and I expect the trend will only worsen as we get a clear picture of just how much of the Arctic is about to melt out. The extent/area numbers hide this year's volume deficit (in particular, across the Beaufort/western CAB).

I wonder if in addition to a July cliff, we also see an unprecedented continuing drop in late August/early September. There will be so much more thin ice at that time than normal (and so much more open water) that this year may seem to be a more plausible candidate for "delayed refreeze" than even last year, which in itself was... shocking.




26
Consequences / Re: Sea Level Rise and Social Cost of Carbon
« on: June 22, 2017, 07:49:09 AM »


Latest MSL data from March 2017. Any thoughts/explanations on why MSL has been flat for over a year? Seems incredulous due to all the melting of Greenland and Antarctica? Could it be related to in the influx of colder water reducing the thermal expansion effects?
This might have something to do with it.



27
Arctic sea ice / Re: The 2017 melting season
« on: June 20, 2017, 04:55:05 AM »
If UBremen wasn't a 150K+ area drop into the 19th I'd be surprised. With the impending first GAC of the season I anticipate an end-of-June cliff unlike any we have seen in recent years, and I would bet that the gap with 2012 widens once more in terms of volume (and I also suspect 2017 surges into first place on area). The Atlantic/Russian sectors are going to be absolutely hammered.

28
Arctic sea ice / Re: The 2017 melting season
« on: June 12, 2017, 08:16:10 PM »
12z GFS shows 100F+ readings widespread across Siberia D7-D10...


29
Arctic sea ice / Re: The 2017 melting season
« on: June 12, 2017, 04:55:05 AM »
From his post, it just fell.  And since the temperature is now over freezing, it won't persist long.
And yes, it is totally within recent experience.

Let me get this right, you are trying to claim that a single unremarkable snowfall somehow is an indication of what?
There is still snow across the east Siberian Arctic coast, when there has not been at this date since 2006. That is snow that has accumulated over the entire winter, not "a single unremarkable snowfall". Also, do not fall into the trap of thinking that because global warming is occurring, that all events relating to things warming up (snow melting, heat waves, ice melting) must be unusually strong. If no strong heatwave appears, it will last much longer than two or three days.

http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2006&ui_day=161&ui_set=0
I would call the current situation more than slightly abnormal.


30
Permafrost / Re: Negative Feedback of Positive Snowfall Anomalies
« on: June 09, 2017, 05:40:13 PM »
More snow in late spring and summer would be a negative feedback due to albedo...

Warmer Arctic --> more evaporation --> more snow fall --> reflects SW radiation in the summer --> cooler Arctic.

But we don't see more snow surviving into summer, we see less and less snow cover in the summer - check the Rutgers data or the NOAA snow cover data. More extensive snow cover and thicker snow appears in the winter, when the sun is not shining... no albedo negative feedback.

Instead, we have a positive feedback...

Warmer Arctic with more open water --> more evaporation --> thicker snow on the ice  --> insulates the ice from bottom freeze --> thinner ice, melts sooner --> more open water in summer --> reduced albedo = warmer --> more evaporation... and more open water also makes more evaporation --> more snow.

Also, thicker snow on land insulates the permafrost, preventing it from radiating away the heat gained during melt season. The top surface of the snow is much colder, but the bottom is warmer, just like a blanket. When the snow melts in spring, the permafrost starts out warmer than usual.

...

Another effect of snow might be possible... consider this scenario, tell me if it makes sense:

Snow falling on open water makes slush, which soon solidifies into solid ice if it's cold enough. If the Arctic ocean surface is a little warmer, and if much heavier snow falls on the water forming a very thick slush layer, it might not be able to freeze solid.

Solid ice has a much higher thermal conductivity than water, so a thick slush layer would act as insulation on the bottom of the ice, trapping water in its voids, preventing heat from conducting upwards through the ice as quickly... in addition to the air/snow insulation effect on the top of the ice.

This would be consistent with the observations that Arctic ice seems "rotten" and weak. Maybe it has more slush within it than historically.

Plausible?

Wanted to bump this... as this seems to be the first year since the mid-80s with the exception of 95 or 96 that May has seen a glaringly positive snowfall anomaly.

http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=5
 
The departure was larger in Eurasia than North America though both saw positive anomalies... I would chalk this up to the Himalayas having more area than the Rockies + the very staunch endurance of the Siberian pack.

But more importantly: does this confirm that even with all the heat energy we've accumulated, that we *could* indeed see a snowball effect given increasing open water near the North Pole, and corresponding moisture feedbacks? The rhetoric around opposition to my arguments for this potential focused on the recent lack of spring snowcover... which 2017 proved is *not* an absolute, even with temps at the warmest levels they have ever been (or very close).

Beyond the Rutgers graphs, snowcover anomalies continue to be impressive as we approach the solstice. Per the Canadian maps we are over +1SD in extent still, and per the Finnish volume graph, we are... well... above and beyond what any year has seen previously at this time.



It is important to note that although the relative % of the NHEM that is snowcovered is still quite low, compared to normal it is, if the Finnish graph is to be believed, many many standard deviations removed from normal. I would argue that given June insolation's far greater values than January's, the impact of this residual/in some areas still-growing snowpack is greater now than at any point in the winter. The question is whether this will allow the Arctic to retain some integrity this year, and on that point, I think the answer is no, which begs the question of how low the volume goes this year (both for ice and snowcover), and subsequently, whether 2018 continues the rather extraordinary bucking of the decadel trends we have seen this year.



I would posit that the enduring anomalies in the Himalayas will outlast Siberia and may even survive the summer, setting up explosive fall growth for the NHEM as we see 1) an extraordinary amount of mountaintop snowcover survive the NHEM summer, and 2) record low sea ice volume as we enter the fall months.

The Himalayan anomalies could also further the deterioration of the Arctic as we see the Siberian anomalies continue to erode (and unlike the Himalayas, parts of which continue to see massive snowfalls, snow is mostly finished/only falling in relatively token amounts along the Siberian coast). As Siberia loses its snowpack, I suspect that the jet stream will be able to waft enormous amounts of heat up and over the Himalayas (with the snowpack there encouraging +500MB height anomalies to the north), and that air is going to head directly into the heart of the Arctic.

31
Arctic sea ice / Re: The 2017 melting season
« on: June 07, 2017, 12:09:45 AM »
NH snow cover anomaly for May (from Diablobanquisa's blog):



Quite the positive anomaly, eh? The first one in 12 years.
seems that the positive uptick i was anticipating as possible is now a reality... but how temporary will it be and will it worsen in subsequent years? i suspect the correlation wrt volume is direct...

32
Arctic sea ice / Re: The 2017 melting season
« on: June 04, 2017, 08:21:08 PM »
With snowcover in Siberia's far North mostly melting out now, it seems less unlikely that the GFS projections will not verify. It has been consistent in blasting the Laptev/ESS with heat for several days now, and the forecast for said event is now within the D10 window. By no means a certainty, but if this does come to pass, the fast ice along the Siberian coast and the sea ice within Laptev/ESS are likely to disappear very quickly within the next two weeks. Combined with the rapid melting across the North American coast we are already seeing, and ongoing Pacific-side melting, this should pave the way for continental heat blasts to begin affecting the heart of the CAB by mid-June.



Combined with the forecast for the Atlantic sector, which is imminently going to endure a massive heat influx from the NATL and persistent LP that is conducive to FRAM export and bottom melt, it would appear we are indeed in for a June cliff this year. Whether Hudson/Baffin cooperate fully remains to be seen, but they will melt out one way or the other anyways -- if they coincide with the rest of what's imminently happening, the fall will be that much more impressive.

I would also argue that the forecast for the next two weeks implies that 2017 may actually increase its lead wrt volume loss vs. 2016 and 2012 -- things are looking extremely bleak on all fronts, and the large positive anomalies at the jaws of the FRAM are about to meet their doom, which could spell an additional increase in the current gap vs. 2012, and not in a direction that is favorable to the sea ice.

33
Arctic sea ice / Re: The 2017 melting season
« on: June 04, 2017, 06:37:28 PM »
HYCOM shows quite a situation developing over on the Atlantic front -- its accuracy would seemingly be confirmed by DMI, which shows the normal seasonal uptick in SSTs across peripheral seas, but a very abrupt and dramatic warming vs. normal (at least, I would think) across Barentz/Kara. It seems the huge pool of warm water in the NE NATL is finally making its presence known further to the north, just in time for the peak of the melt season.

This should have two main impacts; the first is that bottom melt is going to continue and worsen along the Atlantic front, and all the easy ice that has appeared there since last winter is about to melt very quickly. The second is the accumulation of warm water N of Scandinavia, which as summer goes on, should further lend itself to enhanced storminess/cyclonic activity, which will add in the continued export from FRAM while also destroying whatever remains along the Atlantic periphery through wave action/even stronger bottom melt.



34
Arctic sea ice / Re: The 2017 melting season
« on: May 31, 2017, 09:39:07 PM »
IMO it seems like the Atlantic sector ice is going to face a rapid collapse over the coming 2-3 weeks -- the next week alone should see major losses in Kara, Barentz, and the Greenland Sea, with large areas of each falling victim to both bottom-melt and wind-driven ice loss. The following week or two should kill most of what remains. Seems like the date of the impending cliff is moving closer and closer given these developments.

PS: this is fantasy-range GFS, but this is the first run of the model where such extreme temp anomalies are appearing in the peripheral seas. I would think that this indicates that the areas of largest anomalies are anticipated to soon be completely or almost entirely ice-free... so while the forecast date is far away and the forecast itself is likely off substantially, this would seem to indicate that we will imminently be dealing with open water across large sections of the Arctic where it has never appeared this early before.


35
Arctic sea ice / Re: The 2017 melting season
« on: May 30, 2017, 03:22:59 AM »
The very heavy snowfall held out through May slowing the predicted May decline in the 50 day sea ice model. That snow is almost gone in north America now so I think the melt rates are going to start reflecting the model prediction soon. Siberia is warming up fast, but has more snow to melt. For predictive purposes it's probably better to smooth that curve out instead of predicting a cliff, in my opinion. But we all know how hard it is to predict the weather so let's not get overconfident in forecasts. No matter how we look at it, the forecast for the ice looks bad.

The GFS may overcook snow melt, but for what it's worth here's the forecast loss over the next week. It may be too aggressive, but if the forecast heat materialises in Siberia the snow can't last much longer there.

edit: - I added the attachment I'd had forgotten, and the replaced with one that will play /edit

With the state of the ice on that side and a series of lows in the Kara Sea blowing into the Barents and sucking warm moist air in, more and more open water will appear and start warming. Does the ongoing weather setup of a high surrounded by lows cause rotation and compaction of  the centre, while lows disperse ice at the edges? With the mobility and fragility and thinness could the pack become entirely separated from the margins of the Arctic Ocean, or even split into pieces rather than develop arms.

If the summer is sunny and the Ocean takes up a large amount of heat, then the autumn turns stormy like last year the minimum could come very late. During the winter on the freezing thread it was suggested(if I can trust my memory) that when we go sub 1million km2 sometime in the next few years, it could happen in October.

It's too early to discount the possibility of going icefree this year. Things have started ominously. We just have to watch what unfolds
That attachment would explain why UBremen is now showing huge black/grey patches over Beaufort and Chuchki. HYCOM shows large concentration drops beginning soon across Chuchki as well. I suspect that large parts of both seas will be open by 7/1, and while we haven't yet surpassed 2016, we aren't far off. When we *do* finally surpass it -- which I think is almost guaranteed, comparing thicknesses in both Beaufort and Chuchki -- the advance will come much quicker than it did last year, and the rest of the CAB will soon follow/quickly melt into oblivion.

I also suspect that despite the seemingly delayed momentum in melt this year, the relative lack of volume compared to all other years on record means that the minimum is going to come late, possibly in a record-setting way, which will likely delay refreezing well into October/November, echoing last year in an even worse way.

36
Arctic sea ice / Re: The 2017 melting season
« on: May 28, 2017, 10:47:08 AM »
Wipneus posted a nice animation today in his Home Brew AMSR2 thread, showing the torching in Beaufort:


The dark greys seem to directly correspond to where the ice was left extremely unusually thin, wonder if it melts out in a matter of weeks instead of months -- could turn very bad into extraordinarily bad.

37
Science / Re: Early Anthropocene
« on: May 28, 2017, 09:54:56 AM »
I wouldn't be so sure that humans were not in the Americas in the last interglacial. Though perhaps not homo sap. These ones have up to 2 or 3 times as big a brain as us. Though its not just in the Americas that the conehead type is found. There is also the matter of raised garden type geoglyphs of very large scale in the Altiplano with glacial period sediment fans over them. Not to mention extensive submerged Megalithic structures in the Caribbean etc.

The Mitochondrial  DNA maps show a Ice age civilisation spanning the tropical Pacific. Not so the Y chromosome ones. The men tend to invade new territories while the women stay put.
I believe those head shapes were caused by molding via whatever torturous devices they had, but more important re: humans/hominids in the Americas is this recent discovery which pushes arrival back to 130K yrs ago!

https://arstechnica.com/science/2017/04/unknown-humans-were-in-california-130000-years-ago-say-scientists/

38
Greenland and Arctic Circle / Re: Greenland 2017 melt season
« on: May 28, 2017, 05:10:26 AM »
bbr2314 has pointed out (on 2017 melting season) that Greenland accumulated an amazing additional weight of snow last winter (700 million gt?). I show the graph again. It is from http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/.
Well worth a read.

If, as many have suggested, this massive increase in snowfall is likely to become frequent in future years, this must have consequences. One could easily imagine a warming world where Greenland accumulates vast additional mass through snowfall in winter and correspondingly greatly increased melt in summer.  Sea level rise would reduce or increase depending on the change in net SMB over the years, while surely a vastly increased melt flooding into the Atlantic could change just about everything.

Trying to think it through has given me brain-ache.
It should be noted that the blue line seems to directly correspond to 2017's lead over other years in terms of lack of sea ice, and the gap had narrowed to merely record-setting (instead of hugely record-setting) since extent fell back in line with the more "normal" recent years. Seems to be a direct correlation?

39
Arctic sea ice / Re: The 2017 melting season
« on: May 28, 2017, 04:11:15 AM »
Above the CAA clockwise rotation of the pack teases open the cracks and opens more big leads at the margin of the fast ice. This view shows the north west of Ellesmere Island (at bottom right) and the Islands to its west
If HYCOM is to be believed, those widening cracks are going to turn into gaping fissures over the next few days, and will possibly extend all the way through to the Atlantic, as the ice being drawn into Nares separates from the main CAB.

40
Arctic sea ice / Re: The 2017 melting season
« on: May 28, 2017, 01:08:55 AM »
The CAA is going to be absolutely smoked in the next two weeks...




41
Consequences / Re: Climate change, the ocean, agriculture, and FOOD
« on: May 28, 2017, 01:02:32 AM »
Having worked on development projects in Pakistan,  India and Bangladesh I was required to understand the overwhelming importance of rivers such as the Indus, the Brahmaputra and the Ganges to just about everything. And the source of the life giving waters is the Himalayas.
The conventional wisdom has it that warming will increase summer melt until the glaciers are sufficiently diminished (in 20, 30 years?). Then food supply becomes a big problem as melt volume decreases.
Any snowfall increase or difference in melt season timing changes the water balance equation.  What is happening in the Himalays today and last winter will have a big effect on prospects for food supply in the northern part of the Indian sub-continent.
Water resources are already a major concern. So while the theory behind increases in snowfall may belong elsewhere, many will be watching snow melt in the Himalayas with apprehension.
Indeed. I wonder if the Himalayan snowfall anomaly will correlate to an event mirroring this one later in the summer -- the additional snowfall would seemingly lead itself to even more moisture availability than normal, combined with all the excess we are seeing from the increasingly open Arctic...

https://en.wikipedia.org/wiki/2010_Pakistan_floods

42
Consequences / Re: Climate change, the ocean, agriculture, and FOOD
« on: May 27, 2017, 08:24:46 PM »
bbr1234 this needs to be taken to the thread I linked or any other relevant thread, but not here.
I don't mind if it is moved but it is pretty relevant to food, the Himalayas border 3 billion of the world's population and continued changes to the weather here will result in catastrophes to harvests in both the Indian subcontinent and China...

43
Arctic sea ice / Re: IJIS
« on: May 27, 2017, 08:14:40 PM »
IJIS:

11,519,803 km2(May 26, 2017)down 25,091 km2 and 6th lowest measured for the date.

NSIDC has it at 7th place, "behind" 2016, 2014, 2011, 2010, 2006, 2004. Unless some dramatic melt starts happening it will "fall behind" even farther. After getting such a huge head start, what can explain the slow drop?
Multi-year ice pushed into the Atlantic death zones and very durable first-year ice in the Hudson and Baffin Bays, which has dealt with very low temps in recent months. This will all melt out anyways, but it is extending 2017's lead over the other years "artificially" if you will (IMO).

44
Consequences / Re: Climate change, the ocean, agriculture, and FOOD
« on: May 27, 2017, 08:03:59 PM »
Gerontocrat, bbr1234 has been discussing positive snow anomalies for a while. You may find the thread "negative feedback of positive snow anomalies", https://forum.arctic-sea-ice.net/index.php/topic,1932.0.html, interesting. It has been set up to discuss this theory, which I personally don't subscribe to.
No worries :)

I have a question, though, that you or others may be able to answer:

Obviously solar insolation peaks in late June, but generally, NHEM temperatures peak in early/mid August.

For the Himalayas specifically, if abnormal snowcover is able to survive through to early July, would this translate into an earlier "end" of summer for surrounding regions, and the beginnings of additional accumulations far earlier than previously? (or rather, wouldn't that in effect result in year-round accumulations in the areas that remained abnormally snowcovered?)

Checking various weather stations in the Himalayas, it looks like snow levels are expected to climb to ~18,000 feet before dropping again after the next week or so. The incoming tropical cyclone over the Bay of Bengal is going to result in some absolutely *massive* snowfalls across the Eastern Himalayas, with upwards of 150" of snow predicted in a two-day timespan.

I would think that if current trends continue, we will eventually hit such a point that snow does begin accumulating in elevations where it normally melts, for the duration of "summertime". And as the Arctic continues to melt -- perhaps even enhanced by the newfound/growing fortitude of the cold pole surrounding the Himalayas, which could serve to encourage 500MB blocking to its north, in essence updrafting huge quantities of heat from both the Indian and Pacific Oceans into the Arctic -- the added atmospheric water vapor is going to accelerate this occurrence (IMO).

We could be talking about a large region of the globe entering an extended period of winter with only a brief/no interlude of "spring". Of course that doesn't mean the snow in these regions will see no melt whatsoever, but as long as the bulk survives the summer, it will (IMO) lend itself to a substantially earlier arrival of "fall" in the surrounding areas, and additional accumulations of snowfall in surrounding lower-lying elevations vs. what we have seen previously, further accelerating the shift.

It's difficult to describe what I am saying exactly and I'm not sure I've done it above, but if someone can either destroy or affirm my relatively inarticulate suppositions above, I'd appreciate it. :)

45
Arctic sea ice / Re: The 2017 melting season
« on: May 27, 2017, 06:57:30 PM »
As we lose snowcover, temps are going to spike to extraordinary levels over the far northern tier, with dual areas of +20-25C anomalies now anticipated across Siberia and the Yukon... this time period is preceded by mid-90s over much of the northern Prairies as well.

It is probably a matter of weeks until we see much of these regions burst into flames, which will

A) add vast amounts of smoke to the Arctic, increasing insolation underneath and depositing soot onto the ice, decreasing its albedo, and

B) probably result in another Fort McMurray situation elsewhere in the Prairies or Siberia -- the amount of warmth depicted is truly staggering.



46
Arctic sea ice / Re: The 2017 melting season
« on: May 27, 2017, 07:06:38 AM »
I would have to guess this is extremely abnormal; per the GEM and other models, the Himalayas may end up becoming the coldest spot in the Northern Hemisphere, at least temporarily, due to the abundance of snowcover:

Anomalies:



Absolute temps:



Quite incredible, and I believe, unprecedented?

47
Arctic sea ice / Re: The 2017 melting season
« on: May 27, 2017, 05:36:33 AM »
It should also be noted that North American volume has nosedived from way above average to normal this month. While this is hardly unprecedented, the sheer cliff we have seen will amount to ~700KM3 of volume by the end of the month. Seasonal discharge is normally quite slower, and also happens earlier in the season than this year in most years, so this will have some substantial impact on the NATL, or perhaps already is, given how cold SSTs are off Quebec/Newfoundland (and the implications on land were clear given the massive floods we saw in Quebec). How much more volume will it take before the impacts escalate even further, and how much farther down the line til that happens? It could feasibly occur next melt season...

What was the volume lost by Lake Agassiz during discharge?
Interesting question in itself though OT here, so I'll keep it short. It seems the answer is several thousands of km3, all discharging in the same direction, as opposed to 700 km3 over a very large area discharging in several directions and partially seeping into the ground. One paper I've found, https://pubs.er.usgs.gov/publication/70032297, provides modeled constraints on Lake Agassiz discharge of 1600 km3 - 9500 km3 through the St. Lawrence Estuary. So no, I doubt the snowmelt will escalate impacts on this or next melt season.

I think the 700KM3 mostly discharged through St. Lawrence, considering the vast bulk of snowmass in North America was in Quebec prior to melting (very anomalously deep). Other watersheds would be Hudson Bay and directly into Baffin Bay, but the bulk would still be running off through the Atlantic, which, IMO, has increased its relative impact.

It cannot be denied that this will have some impact on the melt season -- albeit probably fairly small -- but it should be emphasized that if this trend continues (anomalously high snow depth + anomalously late/rapid melt), the eventual impacts will be much larger than we are currently seeing.

In any case, thank you for the Agassiz data points, and Hyperion brings up good points too re: gradual release through separate events. I wonder what the difference between a 700KM3 discharge in one month vs. a 1,500KM3 discharge in the same time period would be WRT impacts to AMOC? I would think that doubling the melting would pass the threshold of "significant" given that temps SE of Canada are already colder than most any year in recent record.

Finally, it should be noted that Greenland's surface-mass-balance is... *substantially* higher than normal through this winter, in fact, above any year since record-keeping began for DMI. While most/all of this will melt over the summer, it shows that the oscillations we are seeing are now resulting in substantially more winter snowfall over much of the Northern Hemisphere, which is impacting weather patterns further into the spring than it previously did thanks to the sheer increase in relative volume versus past years.





48
Arctic sea ice / Re: The 2017 melting season
« on: May 26, 2017, 09:22:53 PM »
Snow cover/volume is obviously still dropping somewhat, but holy cow -- the departure from norm has never been larger as a relative % this season. We are now roughly double++ where we should be, thanks mostly to the Himalayas, and partially to the northern tier of Russia. The Himalayas may endure the entirety of the melt season IMO!




It should also be noted that North American volume has nosedived from way above average to normal this month. While this is hardly unprecedented, the sheer cliff we have seen will amount to ~700KM3 of volume by the end of the month. Seasonal discharge is normally quite slower, and also happens earlier in the season than this year in most years, so this will have some substantial impact on the NATL, or perhaps already is, given how cold SSTs are off Quebec/Newfoundland (and the implications on land were clear given the massive floods we saw in Quebec). How much more volume will it take before the impacts escalate even further, and how much farther down the line til that happens? It could feasibly occur next melt season...



What was the volume lost by Lake Agassiz during discharge?

Finally, it should be noted that given the cliff seen in NAmerica this past month, we could feasibly see something similar occur across the Himalayas during the summer. Whether it happens or not remains to be seen, but if it does, that would portend epic flooding across the Indus Valley and Pakistan (IMO).



49
Arctic sea ice / Re: Latest PIOMAS update (June)
« on: May 26, 2017, 09:03:02 PM »
The decline of ice in the Pacific and the cool period in the area near the pole this May are a function of the weather. At winter's end in the Arctic the polar vortex was displaced towards the Barents and Kara seas.

If this pattern persists we will see a strong dipole develop with a strong transpolar drift. Hopefully, it won't be as persistent as 2007. Right now the snow cover pattern is supporting the persistence of warmth in the Beaufort sea and cold on the Atlantic side of the pole.
Atlantic SSTs are far colder than any year since/including 2012 (based on HYCOM maps), at least the far NW ATL. The heat is displaced toward Europe and also N of Scandinavia. The contrast with recent years is quite extreme, and would seem to indicate severe disruptions of whatever previous influence the Gulf Stream had SE of Newfoundland.

50
Arctic sea ice / Re: The 2017 melting season
« on: May 17, 2017, 08:53:51 PM »
Most of the ice in the Hudson bay, Labrador sea Bay, The ice on the coast of Greenland south of the Denmark Strait has a blueish tinge on Worldview from the recent high temperatures. It wouldn't surprise if they melt out quickly now, particularly considering the warmth and rain predicted over the next week.
I agree re: blue-ish tinge, but it is also quite thick -- moreso than in most recent years. Combined with the low SSTs in the vicinity/import from Nares, I think it will prove surprisingly resilient, but I could definitely be wrong!

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