The 2018 melting season

[Ktb]

Maybe I am missing something, but that Slater projection for July 25 looks a lot more like the current ice extent from AMSR2 for June 5 (today) than it looks like, for example, the actual ice extent for July 25 last year (see below -- I've put all three maps together).  [snip]

I believe you are correct and will attempt to contact UofC once again with our collective concerns. Thank you for paying closer attention than I was!

[uniquorn]

I've been looking for a quick way to validate temperatures from models across the Arctic. VIIRS Brightness Temperature (Band I5, Day) and Night overlays seem to work pretty well.
<snippage>

Nice. I edited the palette a bit to show a bigger range of temperatures and stop band15 overlapping the visible ice (just a shame about the clouds)
Temperatures range from ~-1C (light blue) to ~11C(yellow)
It shows Kotzebue Sound warming up very well over the last week.

edit:Not sure that 9C in Kotzebue Sound is that realistic, this might need some more work.
edit2: could be ok, slightly over max average water temperatures for june.
https://www.seatemperature.org/north-america/united-states/kotzebue.htm

Worldview link   https://tinyurl.com/y7parn8f
I only edited Band15, Day and left Night as it was for comparison

[slow wing]

Thanks A-Team, I love those Kevin Pluck graphics at #994!

That raises an obvious question about a related but simpler plot: has anyone done an extent vs. volume scatter plot for the yearly minima? Presumably! But I don't recall having seen one.

Presuming the plot has been done, would it be amenable to any sort of simple fit constrained to go through the origin & with a finite slope at the origin (corresponding to the average thickness of the remaining ice at the end of the melt season on approaching a blue ocean year)? (A quadratic going through the origin would be the obvious first form to try.) How much scatter would the yearly values have around the fit?

In trying to relate it to the complex physical reality, would it be expected to be predictive at all?

(Sorry for being slightly off-topic, Neven.)

[uniquorn]

There are lots of ideas about sea ice minimum prediction here
https://forum.arctic-sea-ice.net/index.php/topic,2285.msg156757.html#msg156757

[stjuuv]

That raises an obvious question about a related but simpler plot: has anyone done an extent vs. volume scatter plot for the yearly minima? Presumably! But I don't recall having seen one.

Presuming the plot has been done, would it be amenable to any sort of simple fit constrained to go through the origin & with a finite slope at the origin (corresponding to the average thickness of the remaining ice at the end of the melt season on approaching a blue ocean year)? (A quadratic going through the origin would be the obvious first form to try.) How much scatter would the yearly values have around the fit?

Something like this? I didn't match exact dates, but rather used yearly minimum values from these two sources:

• ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/N_seaice_extent_daily_v3.0.csv
• https://sites.google.com/site/arctischepinguin/home/piomas/data/piomas-sumdata.csv.txt?attredirects=0

[Neven]

NSIDC Compactness quite high for the time of year, which suggests there's not much melt ponding going on, and apparently all that water between floes in the Beaufort is too coarse for NSIDC's low resolution (I'll see if I have time tomorrow to look at compactness using other data sources).

But if the forecasts are right, this year's trend line should start to drop more vigorously soon.

[aperson]

Updated D1-D9 run of the cyclone from 18z GFS. The D5-D9 window shows an interesting synoptic-scale feature that will likely verify in some form, since there isn't too much variance in the expected speed of the cyclone track. A high amplitude jet streak across North America creates an omega block pattern that the cyclone runs into. This causes the system to stall and slowly track eastward over the CAA, putting the garlic press in full motion for a sustained duration.

[Neven]

Very interesting ECMWF forecast, as presented on Tropical Tidbits. Of course, the strong, but short-lived cyclone, followed by a strange-looking Dipole. 

I'm very curious to see what this will do to the ice, especially in relation to that open water on the Siberian side of the Arctic.

[aperson]

Very interesting ECMWF forecast

I'm also excited to see 00z, given that a new release of ECMWF was just deployed:

https://software.ecmwf.int/wiki/display/FCST/Implementation+of+IFS+cycle+45r1

There is one change that should greatly benefit us:

Weakly coupled sea-ice atmosphere assimilation applied with the use of OCEAN5 sea-ice (instead of OSTIA) in the surface analysis of the high-resolution (HRES 4d-Var) and the ensemble of data assimilations (EDA) analyses;

[jdallen]

NSIDC Compactness quite high for the time of year, which suggests there's not much melt ponding going on, and apparently all that water between floes in the Beaufort is too coarse for NSIDC's low resolution (I'll see if I have time tomorrow to look at compactness using other data sources).

But if the forecasts are right, this year's trend line should start to drop more vigorously soon.

I read this, and it just has me scratching my head when I consider (1) the lack of snow cover over most of the pack (2) the serious above normal temperatures we've been having outside of the central pack (3) the relatively cloudless conditions, particularly over the ESS, Chukchi and Beaufort.

I come back to the more recent nature of the pack itself, with much smaller expanses of ice, and less durable as well, and wonder if there is melt ponding, but it is at small enough scales that it's flying "under the radar" so to speak.  The other though I have is, if the ice is sufficiently young, that it may not be sufficiently sealed to permit large standing bodies of water to form and persist.

[Hyperion]

Very interesting ECMWF forecast, as presented on Tropical Tidbits. Of course, the strong, but short-lived cyclone, followed by a strange-looking Dipole. 

I'm very curious to see what this will do to the ice, especially in relation to that open water on the Siberian side of the Arctic.

Strange it may be but that double dipole if it eventuates would be sucking all the heat out of central Eurasia and north America and dumping the Arctic cold down their west coasts, with a new cyclone seeming to be forming up to repeat the cycle.

[Neven]

I read this, and it just has me scratching my head when I consider (1) the lack of snow cover over most of the pack (2) the serious above normal temperatures we've been having outside of the central pack (3) the relatively cloudless conditions, particularly over the ESS, Chukchi and Beaufort.

I'm scratching too. What does it take for some serious melt ponding to be produced during May? I hope to find some time this week to compare this May to previous years (particularly 2010 and 2012) and ask Dr David Schröder what his model is saying.

[RikW]

My gut feeling says the ice is too poreus to see melt ponds.

Just being fractured won't be enough I'd say. Instead of large melt ponds you have several small melt ponds, but 10 melt ponds of 1 km2 or 1 of 10 km2 is still 10 km2 of melt ponds. If the ice is too fractured I guess we should see it on the satellite images.

[Neven]

Over on the extent and area data thread, Wipneus posted this yesterday:

[Hyperion]

Meltponding coming up. Serious drenchings of up to 22 mm per 3hr rain currently underway on the laptev and Greenland coasts. Plenty of inbound TPW to sustain them. Decent falls also up to 5mm per three hours over the ESAS. Temps above freezing surface to high altitude and high winds aloft assure us this is wet stuff. Surface and 850hpa~1.5km shown. In coming ocean heat ramping up via storm surge tsunamis breaching the north sea shallows at depth, and the Newfoundland current pinching of the southern exit route for the Gulfstream by squatting off the coast of Europe.

[Pmt111500]

My gut feeling says the ice is too poreus to see melt ponds.

Just being fractured won't be enough I'd say. Instead of large melt ponds you have several small melt ponds, but 10 melt ponds of 1 km2 or 1 of 10 km2 is still 10 km2 of melt ponds. If the ice is too fractured I guess we should see it on the satellite images.

The extent Vs. Area plays also a part, and various systems of averaging over days. Might be they're still there but drain too fast to get noticed on released numbers.

[aperson]

Keeping my eye on some unreal PWATs for the region forecast by ECMWF (and to a lesser extent GFS) after the cyclone crosses over and runs into an omega block.




This would be a substantial rain event across the CAA. A nice cherry on top after the wind, rain, and wave show we're about to witness.

[Often Distant]

[Often Distant]

Fire.

[Gray-Wolf]

Try and carry a plate of water if you roll it from side to side and see how much water is left by the end?

If slight swells pass through shattered ice then how much water will get 'spilled' by the ocean's motion?

[ArcticMelt1]

The past spring is definitely warmer than the spring of 2017.

[Neven]

Here are my temperature graphs for May, Atlantic second warmest on record:

[Hyperion]

The heat and moisture being dragged in by this beast are already phenominal. Winds and Temp's at 1000hPa

[Hyperion]

But it sure is the Green Islands that are copping the rain!

[Hyperion]

And holy whirling dervish's Batman, looking 24hrs ahead, we have a swarm of 8 cyclonic circulation's on the water from 30 to 70 degrees nth threatening to suck the entire Ocean of water vapour northwards.

[Pagophilus]

The entire Laptev Sea is in line for sustained, strong, warm winds from Siberia for at least four days starting tomorrow, according to nullschool.   In addition, that huge gap in the ice in the Laptev Sea means large waves can develop there.  The Lena River, BTW, has just about melted through the fast ice through to that gap in the Laptev.  Warm waters will be arriving by that route also.

These forecast winds will be coming from the hot central portion of Siberia and they are thus likley to be warmer than those about to blast the Kara.  I will confess I was focused almost entirely on the north/east Kara Sea, because the cyclone is due to pass over there.  But what is happening to the Laptev (and the adjacent CAB) could be significant.  I chose the wind speed and temp point (green circle) in the middle of the Laptev as conservatively reasonable for what might be happening to the sea and ice.

[marcel_g]

I'm also very curious as to what will happen to the ice with this cyclone. It looks like the area between Laptev and CAA will get churned up, first with winds pushing the ice towards Svalbard, and then with winds pushing it back.

Laptev looks to get wind and warmth, so how much will it melt back?
how much will that gap open up as the ice gets pushed towards CAA? How much melting will occur under the storm in the CAB? Enough to cause melt ponds? The storm looks to bring cloudy weather, so perhaps maybe not?

On the Pacific side at around 5 days out however, things look bad for the ice. If the forecast holds, that whole side will be getting at least a few days of sunshine and warmth. I sure hope the forecast is wrong.

[Pagophilus]

I believe you are correct and will attempt to contact UofC once again with our collective concerns. Thank you for paying closer attention than I was!

Thanks, Ktb.  I admire your open and generous response, and will do my best to use it as a model for my own.  It is disconcerting that the open ocean is closer to the pole on June 5 than it was on July 25 last year.  Maybe southerly ice drift will have something to say about that later on, but still...   

[Shared Humanity]

Here are my temperature graphs for May, Atlantic second warmest on record:

Interesting that the Siberian sector is experiencing a steady decline over the past 12 years.

[A-Team]

Before the weather hits ... thin ice according to UB SMOS.

[Koop in VA]

Thanks A-team.  Presenting those SMOS images prior to the storm is really beneficial.

Taking a look at the current thickness of the ice in the storm's path, I tried to eyeball a similar thickness distribution earlier in the season.  The most applicable comparison is the Bering in mid to late March.  What you can see is that most of the ice that was less than 20 cm thick melted out in a little over a week's time frame during the end of March.

I then examined the temperatures in a city fairly close to the Bering ice in March (Nome, AK was my chosen proxy) and only 1 day did it have temperatures above freezing (34 degrees F) during mid to late March.  Most of the days had high temperatures in the 24 to 28 degrees F range.

So if the lesson learned from the Bering in March applies here, anything that is in the blue to green range on the SMOS (ie under 20 cm worth of thickness) has a decent chance to melt out because the temperatures, the rain, the wind are all going to be higher in the storms path than they were in the Bering in March.  This is a significant area of ice.  However, with all that said, I'm guessing that the reduction may not be as significant as the Bering in March due to lack of nearby open ice and therefore lack of high abnormal SSTs that played a significant role in melt out in the Bering in March.

(Side note:  there was some expansion of extent in the Bering after late March but I do not recall if that was due to wind driven extent expansion or actual new ice formation due to temps)

[Hyperion]

Before the weather hits ... thin ice according to UB SMOS.

Do you think that may be to do with soupier and saltier ice? Lower melting point and more surface area...

[Pagophilus]

Before the weather hits ... thin ice according to UB SMOS.

Thanks for this.  It looks like the north/east Kara Sea is even more vulnerable than it has so far appeared.  I guess it is possible the ice extent might get larger (in this zone) for a day or two as the cyclone blows this ice towards and into the Barents Sea.  Eyeballing the AMSR2 maps for June 4 and 5, it looks as this might already be happening.  Large drops in extent might therefore appear once the winds change in a couple of days or so.

[Viggy]

Long time lurker, first time poster!

Alaska Wildland Fire Info on the Pt Hope Fire.
https://akfireinfo.com/2018/06/04/smokejumpers-enroute-to-2000-acre-tundra-fire-near-point-hope/

Exploded to 2000 acres in a single day

[oren]

Yes, the Kara seems to have thinned considerably in the past week. This could easily go poof putting 2018 in the lead, at least temporarily. The Beaufort has also developed an ominous area of thin ice.

[GoSouthYoungins]

An upcoming SUPER CLIFF looks inevitable before the end of the month. CAB looks set for an anomalously early decline in the next few weeks from losses spanning from Greenland to Severnaya Zemlya. The Laptev Sea is about to get slammed with crazy heat in the next few days. Kara Sea is currently getting a rainy heat influx and is fragile.  Beaufort Sea has been getting a bit of heat, which looks set to continue and the concentration is starting to give. Chukchi Sea is consistently retreating. Baffin and Hudson hardly matter but will fall off as always.  2018 appears destined for the lowest extant/area by the solstice. And the problem is that none of this is actually an outlier in the context of record ocean heat and the 4 hottest atmospheric years ever.

[bbr2314]

The models are increasingly depicting a very sustained and continuous torch across Siberia, adjacent seas, and the CAB. Wow.

[aperson]

GFS joins the Euro on a major rain event (on the order of 1"+ of rain in large swaths) across the CAA in the 5d range. This will be due to moisture / warm air advection from an omega block centered over North America.



We're currently looking at over a week more of conditions that will severely negatively impact the ice, all the way from the kara sea to the ESAS and along the CAA.

[A-Team]

Here is the Kara sea ice concentration over the last 34 days according to the higher resolution UH AMSR2. Solid ice, 90-100%, has been replaced with green. WorldView is inset in the upper left; it is mostly too cloudy.

[Reallybigbunny]

Nice summary of Arctic ice conditions from National Snow and Ice Data Center (NSIDC)

http://nsidc.org/arcticseaicenews/2018/06/

[oren]

A 28-day Worldview animation of parts of the Chukchi and adjacent regions. I could swear melt ponds are all over the place, though the bluish tinge seems at times to be due to problematic color correction. BTW, looking around the arctic I can see lots and lots of that bluish tinge, recently appeared.
CLICK to animate.

[NACK]

Nice summary of Arctic ice conditions from National Snow and Ice Data Center (NSIDC)

http://nsidc.org/arcticseaicenews/2018/06/

RBB, thanks for this summary as otherwise  it is quite bewildering wading through the forum with all its cryptographic tables, jifs, etc.

I've been lurking around here for a couple of months and there seems to be a lot more questions than answers (no offense intended); nature is capricious.

To the board in general, I would like to throw a practical query into the fishbowl:

I'm planing a sailing voyage through the Passage this year and am looking for a route with the highest probability of avoiding ice. If one ignored every other consideration, e.g. safety, ease of rescue, national maritime boundaries, common sense) and considered only sea ice extent, what would be the preferred route for an east to west transit (South tip of Greenland to Nome, Alaska)?

It appears to me that the Northern Sea Route, rather then one of the several Northwest Passages would have the greatest chance of success (considering only projected ice extent). The way this melt season has progressed (or not), a voyage through the narrow, icy straits of the Canadian Archipelago could prove to be impossible in a sailboat (assuming no ice breakers happen by at the exact right moment).

[Neven]

Environment Canada has 00z anal surface at 974 hPa:

[S.Pansa]

Ah those Crazy Canucks

In the meantime, pressure has gone done considerably. GFS has it at 964, ECMWF at 962 and thinks it will bottom out at 961 later today.

On the other side of the Arctic Ocean, ESRL thinks widespread melt ponding is taking place. As others I am surprised that this doesn't seem to show up in the concentration/compactness maps/graphs.

[F.Tnioli]

Here are my temperature graphs for May, Atlantic second warmest on record:

Interesting that the Siberian sector is experiencing a steady decline over the past 12 years.

Siberia generates lots of cold air during winters - Verkhoyansk, Oymyakon, etc. So, i think that in the past, normal Jetstream functioning transferred some of that cold around, so less of that cold, heavy air remained for a long time in Siberian sector. Now, with Jetstream weakening, less of that happens, so more of cold air remains in Siberia on _average_ through the recent years, - and there we go, temperatures reflect that.

[Viggy]

In the meantime, pressure has gone done considerably. GFS has it at 964, ECMWF at 962 and thinks it will bottom out at 961 later today.

Welp, did the GFS just throw out a 959?!

[Greenbelt]

Yep latest GFS initializes at 959!

[oren]

Temps in Tiksi, on the Laptev shore, have shot up in the last three days. This is brutal heat.


In Pevek on the ESS shore things are quite opposite, though on a smaller scale.

[Pagophilus]

Kara Sea images, from Worldview, for May 31 and June 7.  I have been frustrated that partial cloud cover has prevented full views of the Kara so I took these two images, one week apart, from Worldview, and altered the contrast in the same way for each, which allows one to 'see' through the lighter cloud cover.

Not a proper scientific analysis perhaps, but a way of supplementing the information coming in from AMSR2, which is showing, at a low resolution, rapidly decreasing ice concentrations in the north/east Kara Sea and a widening gap along the Russian coast.  Pretty much what one would expect from the strong winds from the east generated in the early stage of this cyclone.

Note: I would not read too much into the colors on this image... bluish tinge overall popped up in the June 7 image, but I think that might have been an artefact of the contrast manipulation.

[marcel_g]

If I’m reading climate reanalyzer correctly, it looks like after the cyclone works it’s way across the Arctic Ocean, there’s going to be full sunshine and very warm temps, for a week, for all of the Laptev, ESS, and Chukchi, pretty much all the way to the Pole. Starting in less than 3 days, so part of that forecast is reliable, part is getting too far out.

I’d be surprised if that doesn’t generate a lot of melt ponding and preconditioning of the ice right before the solstice. That’s a very large area of  FYI.

The only positive I could see was that the Beaufort and the CAB north of the CAA will stay cloudy for pretty much the whole forecast.