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subgeometer

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Re: The 2017 melting season
« Reply #2600 on: July 06, 2017, 10:09:09 AM »
The clouds have opened for a moment to reveal the last ice between Laptev and ESS bites, it won't last long.

Windy TV is showing a lot of rain in the next few days at various places - how much damage will 23mm of rain do?

NeilT

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Re: The 2017 melting season
« Reply #2601 on: July 06, 2017, 10:23:31 AM »
Wasn't 2010 was the lowest for this date?

Busy month July, on extent, in the last decade.

The first week sees 2006 and 2010 walk out of the records and head for normality.  The second week sees 2011 drop to lowest and 2016 walk away from record making.

The end of July into the first week of August sees 2011 stall and 2012 depart from all other years and head for the record books.

The next 4 weeks will be telling but, even then, a GAC would be a game changer for the end of year.

For me the most notable thing about 2017, in summer melt, is that it is sitting right at the bottom of the results and there is nothing dramatic about the weather patterns which should be putting it there.  All it needs is one sustained weather event at a critical stage and all bets are off.

« Last Edit: July 06, 2017, 12:12:32 PM by NeilT »
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NeilT

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Re: The 2017 melting season
« Reply #2602 on: July 06, 2017, 10:27:40 AM »
Arbitrary date of Sept. 8th for 2002, 2007, 2012, and 2016. I don't of a point that I am trying to make with this, other than to give some of us an idea of what September sea ice looked like over the years. Many of us were involved in other pursuits at the time. 2002 is on here mainly as a benchmark to compare to.

2000 to 2007 was a pretty dramatic time, all considered. Stuff was really happening.  However I recall some of the more dramatic events, prior to 2005, happened in the October/November timeframe (re-freeze), where normal re-freezing events simply weren't happening.

2005 was shock global news, they even found a new island that was not on the maps.

Old history and, looking at the extent maps, doesn't seem so newsworthy compared to current events.  But it was the first decade of the 21st century that signalled the demise of the ice in the Arctic and it was quite a journey.
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oren

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Re: The 2017 melting season
« Reply #2603 on: July 06, 2017, 12:26:32 PM »
What I found interesting about the inter-year comparison is that 2016 was the only one that inflicted major damage in the region around the pole. Had the ice been thinner in the ESS and Beaufort at the beginning of the 2016 melt season, we could have easily seen a new record low. And this year, that ice is indeed much thinner. The race is very much on even though extent numbers don't and can't tell it.

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Re: The 2017 melting season
« Reply #2604 on: July 06, 2017, 02:47:36 PM »
Could well turn into a record year on the very last day of melt season

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Re: The 2017 melting season
« Reply #2605 on: July 06, 2017, 04:43:53 PM »
@ NeilT
 Thanks for painting in the picture a little better. Those tidbits of info really help those like me, who like I said, had my mind elsewhere at the time.
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Re: The 2017 melting season
« Reply #2606 on: July 06, 2017, 05:01:14 PM »
I think the bering steamhose is raining out heavily and drawing down the condensation energy with the rainfall to sprawl out over the whole pacific quadrant.
The Bering Steamhose is clearly evident in the Precipitable Water gif from the ASIG.

seaicesailor

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Re: The 2017 melting season
« Reply #2607 on: July 06, 2017, 05:42:31 PM »
I think the bering steamhose is raining out heavily and drawing down the condensation energy with the rainfall to sprawl out over the whole pacific quadrant.
The Bering Steamhose is clearly evident in the Precipitable Water gif from the ASIG.
Well whatever the outcome, this seems a concentrated but powerful event. I wonder how long the ice under the rain is going to last afterwards.
Pure speculation, but can the storm of the next few days pick its strength from this injection of humidity?

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Re: The 2017 melting season
« Reply #2608 on: July 06, 2017, 05:56:39 PM »

[note - edited to fix messed-up quote delimiter]

This seemed the right place to comment on Wipneus latest update to his AMSR2 area/extent thread...
 
Slow down in extent to report , and even an uptick in area. Suddenly "only" third lowest place, temporary?


This is IMO temporary... Illusory, even. Much of the day's increase seems to be in ESS + Beaufort, where it is both above freezing from the surface to 850mb and either is, or has in the past 24 hours been, raining heavily.

Also, continued absence of melt-ponds notwithstanding, I'm pretty certain this area is in the process of going full-on "poof". Viz - Peering through the occasional gap in the clouds one can see hints of apparently solid floes devolving into diffuse swirls. I don't doubt that there's a technical term for these - but I've come  think of them this way...

"Blood on the Floor; prognosis is poor".


magnamentis

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Re: The 2017 melting season
« Reply #2609 on: July 06, 2017, 06:09:41 PM »
@cesium62

absolutely, i have no problems with that and even like averages for the exact reason you mention while still it has to be mentioned in that context when slightly above lowest and lowest is the main topic.

StopTheApocalypse

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Re: The 2017 melting season
« Reply #2610 on: July 06, 2017, 08:42:36 PM »
ECMWF and GFS both point to pretty strong (I think, I'm new, so correct me if I'm wrong) dipoleish setup in 4-5 days.

Edit: Screenshot is 120hr, but it starts around 96.

Tor Bejnar

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Re: The 2017 melting season
« Reply #2611 on: July 06, 2017, 09:23:37 PM »
NP elves may need umbrellas next week.  I don't look at the ASIG forecast pages often, and I know I've seen 'green' rain in the Arctic before, but isn't this quite a lot of 'heavy' rain in the forecast? (The 8th has a bunch of 'green' too, but the 13th's includes Santa's workshop.)
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Re: The 2017 melting season
« Reply #2612 on: July 06, 2017, 09:27:52 PM »
Interestingly at 1000hpa only a small area at the centre of the big cyclone over the whole ocean was a bit over zero C. Maxing at 1.4 :
https://earth.nullschool.net/#2016/07/06/0900Z/wind/isobaric/1000hPa/overlay=temp/orthographic=-166.54,91.88,383/loc=169.850,84.763

Whereas this year the pacific half of the basin is almost all above zero. Mostly 2-4C at this just above surface altitude:
 https://earth.nullschool.net/#2017/07/06/0900Z/wind/isobaric/1000hPa/overlay=temp/orthographic=-167.95,90.62,383/loc=-163.070,80.282
I think the bering steamhose is raining out heavily and drawing down the condensation energy with the rainfall to sprawl out over the whole pacific quadrant. Intrigued i is also by the big 850hpa cold air rivers being expelled over Siberia.
I think this comparison shows well that collapsed jets and lots of small mixing weather systems can be mor toxic for ice survival than big GAC scenarios.

I agree it looks like the broken jet stream is the most dangerous feedback, more water vapor  and warmth is being transported northward by big swings in the jet steam plus the increase wave action causing more mobility meaning that ice conditions are likely to become more variable more anomalies more often making “mapping the bombs” more difficult.
Loss of sea ice causes more evaporation, which traps more heat, which melts more ice ad infinitum… faster and faster
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Re: The 2017 melting season
« Reply #2613 on: July 06, 2017, 09:46:56 PM »
Could well turn into a record year on the very last day of melt season

My bet is the ice will follow the gentle path it made until now. And that's enough for new records in all defined measurements. It will just go steeper and steeper until the end of August. There is not much resistance in the pack, the ice doesn't need a special weather event to be pushed to oblivion like it was necessary in 2007, 2012 and 2016. This time average melt will do the job and besides that we are already observing above average melt conditions – at least on the pacific side. This year will be a completely unspectacular walk into uncharted territory. But that's just my little bet.
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Re: The 2017 melting season
« Reply #2614 on: July 06, 2017, 10:24:24 PM »
re the NP elves . Climate reanalyser seems the least reliable source for ppt in the Arctic . It takes the already troublingly warm forecasts from GFS and pops them in the oven . GFS has not and is not forecasting rain at the North Pole until later in the outlook . There has been almost nothing but snow falling this summer north of 80' ; only CR has suggested otherwise at any time .. until now . bc

  oops .. rain .. not snow .. at the North pole ..
« Last Edit: July 06, 2017, 11:58:34 PM by be cause »
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 
 (phew)

Tor Bejnar

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Re: The 2017 melting season
« Reply #2615 on: July 06, 2017, 10:44:08 PM »
Thanks for the temperance talk.  I already knew 7 days was a 'too far in the future' forecast to take seriously (but thoughts of a NH Christmas in hot & muggy July was too tempting).  I thought the 2 days ahead forecast showing Arctic rain (but not at the NP) more likely to be a real forecast.  I take your guidance to mean I shouldn't bet my retirement on that forecast materializing either.
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seaicesailor

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Re: The 2017 melting season
« Reply #2616 on: July 06, 2017, 11:25:46 PM »
ECMWF and GFS both point to pretty strong (I think, I'm new, so correct me if I'm wrong) dipoleish setup in 4-5 days.

Edit: Screenshot is 120hr, but it starts around 96.
It is a dipole in the sense of pairing a high and a low with strong pressure gradient between, but the Arctic dipole often mentioned here would see the high laying more over the American side, and the low or lows sitting over ESS/ Laptev/Kara, creating wind pattern that crosses the Arctic, transports warmth from the Pacific and the continents inside the Basin, and drifts ice fron the Pacific side toward the Atlantic. Somehow this has been a persistent story this year, only that weak and very gradual (imho).
Also that depression over Greenland in the forecast in general has not been typical of this spring/summer, and to me it does not promote the mentioned circulation. Quite the opposite
It is a "quadripole" ha! If that exists. Only that the forecast changes very quickly

Neven

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Re: The 2017 melting season
« Reply #2617 on: July 07, 2017, 12:01:09 AM »
I've received a mail from Dr David Schröder from the University of Reading, with the melt pond distribution his model has produced for the month of May:



And the accompanying text:

Quote
Based on melt pond fraction in May+June we predict a mean 2017 September ice extent of 5.1 (4.6 to 5.6) mill km2 (within the range observed during last 4 years). The likehood for a new record minimum is below 1%. While melt pond fraction has been above 2006-2015 mean values in the western parts of the Arctic, less ponding and melting occurred in the eastern part (see anomaly figures attached) due to more snow and relatively cold temperatures. In the past the regions - where melt pond fraction is low in 2017 - were more important for September ice extent (local pond fraction in areas enclosed by thick contour line show a negative correlation with mean September ice extent of R < -0.3) than e.g. the Beaufort Sea. Consequently, we predict the September ice extent to be quite large in spite of the lowest Arctic ice volume in recent months.

5.1 million sounds a bit high to me, but as we all know, so far the ice on the Atlantic side has been slow to melt (there's even still snow on Taymyr Peninsula!). Looking at the difference in sea ice volume, according to PIOMAS, 2017 and 2012 are almost diametrically opposed:



If those red zones (where the ice is thicker than it was in 2012, according to PIOMAS) do indeed not melt out, it could be enough to keep NSIDC SIE September average above 4.6 million km2 (the poll opening post has the September averages for the previous 10 melting seasons).

The ice there is about to put to the test, because the weather forecast has much of the Siberian coasts dominated by high pressure and anomalously high temperatures for the coming week. As shown by the forecasts that I'm going to post in the next comment.
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Re: The 2017 melting season
« Reply #2618 on: July 07, 2017, 12:13:15 AM »
Because of so much open water in the Beaufort/Chukchi/ESS at the end of last year's melt season, the trail of the first-year ice that formed over the winter is fairly easy to follow in weekly hycom (28 Sep 16-13 July 17) as roughly outlined in the 1st animation below.

Notably a wave of thickening (darkening color) swept up from Banks Island to the Bering Strait. A finger then protruded almost to the Fram if hycom colors can be trusted over this time frame (like swirls of different color paint, ice thickness classes don't mix well).

If so, since this FYI formed under shorter warmer conditions not conducive to maturation of brine exclusion or development of mechanical strength, it is more vulnerable to melt and so constitutes a predictor of residual extent shape loss later in the season.

I also tracked the origin of all the thick islands of ice currently seen in the Beaufort/Chukchi/ESS. One was landfast ice off the Siberian coast near the Strait, an even larger and more persistent landfast segment broke off the Alaskan coast near Utqiagvik (Barrow). This landfast ice did not form in situ but rather by pile-up.

Only a single chunk had any association with the CAA MYI. In other words, the Beaufort gyre has largely been inoperative in terms of thickest ice translocation. Another small chunk may be in works however. This is attributable in part to a much narrow band of MYI than in previous years.

The still image shows the 30 day unweighted average of the black arrows in hycom's dodgy speed and drift product. There does seem to some net motion visible towards the Fram but mostly the ice is just milling about.

The export scene will be picking up steam in the coming week through M'Clure and elsewhere (2nd animation, last 2-3 days).
« Last Edit: July 07, 2017, 02:24:40 AM by A-Team »

Neven

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Re: The 2017 melting season
« Reply #2619 on: July 07, 2017, 12:31:19 AM »
Below are the ECMWF weather forecast from Tropical Tidbits (6 days) and the GFS temperature anomaly forecast (7 days).

As already discussed by others, ECMWF has high pressure becoming more dominant again. Not on the American side of the Arctic, however, but on the Siberian side. This high pressure then shifts on D3 towards the Chukchi, to intensify there. It could grow quite large, partly covering the ESS and Beaufort as well.



Of course, the low pressure over the Central Arctic Basin will probably help to preserve the ice there. And the skewed Dipole set-up will make for compaction towards the CAA Garlic Press, perhaps even widening the Laptev Bite a bit faster.

As for air temperatures, GFS also has some warming occurring in the Kara Sea and the adjoining Siberian coast, so my guess is that the ice south of Novaya Zemlya is toast, as is that last remaining patch of snow on Taymyr Peninsula (finally):



If these forecasts come about, some of that ice in the red zones on the PIOMAS comparison map I posted in the previous comment (indicating that the ice is currently thicker there than it was in 2012), may receive quite a blow. But as we've frequently seen, forecasts change along the way.

Either way, these red zones could very well be the main battleground for this year's melting season. If they do melt out, a new PIOMAS sea ice volume record is probable, and that could mean NSIDC/JAXA SIE ends up very low as well. But if they don't melt out... Oh, right, I already said in the previous comment.  ;)
« Last Edit: July 07, 2017, 12:46:37 AM by Neven »
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StopTheApocalypse

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Re: The 2017 melting season
« Reply #2620 on: July 07, 2017, 12:40:21 AM »
Neven, I think you may have uploaded the wrong photo; your first image has an initialization date of June 26th =p

Neven

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Re: The 2017 melting season
« Reply #2621 on: July 07, 2017, 12:47:15 AM »
Neven, I think you may have uploaded the wrong photo; your first image has an initialization date of June 26th =p

Thanks for catching that, STA. Fixed now.
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subgeometer

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Re: The 2017 melting season
« Reply #2622 on: July 07, 2017, 02:13:35 AM »
Re GFS/climate reanalyser overcooking its arctic forecasts, the models rely on sparse and iffy data on the region. eg GFS sees SSTs up to 16.4C today at the Svalbard hotspot whereas ECWMF/Windy shows SSTs under 6C in the same place. That's a huge difference and makes me wonder what other dubious inputs GFS is fed

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Re: The 2017 melting season
« Reply #2623 on: July 07, 2017, 02:45:27 AM »
Re GFS/climate reanalyser overcooking its arctic forecasts, the models rely on sparse and iffy data on the region. eg GFS sees SSTs up to 16.4C today at the Svalbard hotspot whereas ECWMF/Windy shows SSTs under 6C in the same place. That's a huge difference and makes me wonder what other dubious inputs GFS is fed
The NAM actually shows large parts of the beaufort still below freezing. Compared to the GFS there is around a 10C difference. I'd take these GFS forecasts of heavy rain with a degree of skeptism.

subgeometer

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Re: The 2017 melting season
« Reply #2624 on: July 07, 2017, 04:19:33 AM »
ECMWF/ Windy TV predict a lot of rain today off Northern Greenland, over 25mm in some locations. The forecast temp  there at ground level is 1C today (so surely its rain not snow?)rising to 4C on Sunday and 3C on monday. That can't do the ice there any good

The forecast for 4 or 5 days also shows another large gulp of atmospheric moisture entering the basin via the Laptev. with more substantial rainfall. It comes with a warm airmass at up to 10C at 925mb.

Large areas of the basin are going to see rain over the next 6 days, further conditioning it for destruction, and rendering the outlook from May meltponds irrelevant, in my opinion anyway

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Re: The 2017 melting season
« Reply #2625 on: July 07, 2017, 04:33:25 AM »
subgeometer,
Quote
Large areas of the basin are going to see rain over the next 6 days, further conditioning it for destruction, and rendering the outlook from May meltponds irrelevant, in my opinion anyway
I am thinking likewise. The meltponds have made up for lost time.
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Re: The 2017 melting season
« Reply #2626 on: July 07, 2017, 05:59:42 AM »
subgeometer,
Quote
Large areas of the basin are going to see rain over the next 6 days, further conditioning it for destruction, and rendering the outlook from May meltponds irrelevant, in my opinion anyway
I am thinking likewise. The meltponds have made up for lost time.

Again this year's theme emerges: A warm wet winter leaving more snow but thinner ice. So, which will dominate: late snow melt or thin ice? We are on the verge of learning.

Seems to me that thus far we have been tracking low relative to average weather, but we have yet to see how will the CAB will fare...
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Re: The 2017 melting season
« Reply #2627 on: July 07, 2017, 07:33:42 AM »
TOPAZ4 - forecasting center of the MyOcean project based on HYCOM and ECMWF (for more details go to this link)-  has some unsettling ideas what the current forecast could do to the ice. The forecast for the 15th is of course too fare out to be reliable. What changes most though is the location of the damage, not the scale of it. We'll see ...
« Last Edit: July 07, 2017, 07:50:40 AM by S.Pansa »

Rob Dekker

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Re: The 2017 melting season
« Reply #2628 on: July 07, 2017, 07:36:18 AM »
I seem to be one of the few with an rather optimistic outlook for September minimum.

A month again, my entry (based on May data) for SIPN was 5.4 M km^2 for the NSIDC average September :
https://www.arcus.org/files/resize/sio/27252/sio2017_june_fig1_n33-700x509.png

That was mostly caused by a very large land snow anomaly (4 million km^2) in land snow cover, and moderate 'area' and 'ice concentration' numbers over May.

Now the June numbers are in, but my prediction did not change much.
Here is the Rutger's snow lab data :
http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6

The anomaly is still huge : some 3.5 M km^2 more than last year and a larger amount of land snow cover than since 2004.
This anomaly has to have an impact on the albedo feedback in June, and thus the amount of heat that warmed the Arctic in previous year never made it this year.

Most of us know that ice 'extent' is not a very good predictor, and 'area' is better. There NSIDC's 'area' number for June came in pretty high (8.51 which is 8.54 after the 'pole hole' adjustment) is higher than most years over the past decade.

As a result, the formula I use for June prediction of Sept average (explained here) :
https://www.arcus.org/files/sio/25738/sio-2016-july_dekker.pdf
suggests still 5.41 M km^2 for September 2017.

The difference with May numbers is that the standard deviation of the (hindcast) prediction is now 342 k km^2, which is considerably better than the 550 k km^2 SD for a linear trend.
That means I feel more confident that this year will end up high.

Feel free to shoot me down if NSIDC's September extent number are below 2016's (4.7).
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Rob Dekker

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Re: The 2017 melting season
« Reply #2629 on: July 07, 2017, 07:37:07 AM »
Let me add that in June, there were two periods of about a week each that created a dipole with some serious ice compaction. That brought the extent numbers down considerably.

The data on 'area' and land snow cover and ice concentration suggest that once the weather turns more neutral or cyclonic, 'extent' will start to stall, and there is not enough heat (melting momentum) to continue the rapid extent decline that we have seen so far.
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S.Pansa

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Re: The 2017 melting season
« Reply #2630 on: July 07, 2017, 07:41:40 AM »
And here the comparison with 2012. In general terms it seems to agree with the volume differences of PIOMAS.
And last but not least: The Current TOPAZ4-guess for the volume decline for the first half of July

Neven

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Re: The 2017 melting season
« Reply #2631 on: July 07, 2017, 10:35:05 AM »
Here's the snow cover graph Rob is referring to (pretty spectacular IMO):
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Re: The 2017 melting season
« Reply #2632 on: July 07, 2017, 12:58:29 PM »
I seem to be one of the few with an rather optimistic outlook for September minimum.
...
A month again, my entry (based on May data) for SIPN was 5.4 M km^2 for the NSIDC average September :
That was mostly caused by a very large land snow anomaly (4 million km^2) in land snow cover, and moderate 'area' and 'ice concentration' numbers over May.
...
I was expecting the model had yielded a reduced prediction this month, but it is what it is.
 
Your model has proven to get the right value and/or tendency of the melting season in most if not all years since you have used it (including rebound years as 2013). Correct me if I am wrong.

I only have a "but" with June snow cover: in many of the satellital images, the snow cover over land has been showing a "grey" appearance during June, in other words, that it is only a partial or a thin cover with many spots (trees, tundra vegetation, valleys void of ice) showing a much lowered albedo, as opposed to the absolutely white covers during much of May.

Probably that was taken into account.

If not, the cover this month of June (scarce, dispersed snow cover) that is so special compared to the preceding 10 years (no snow, basically) may not exactly fit in the model that expects a "FULL COVER SNOW" versus "NO SNOW"

Furthermore, may I ask what your model would yield should the snow cover be essentially the same as 2016? Just a curious experiment.

VeliAlbertKallio

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Re: The 2017 melting season
« Reply #2633 on: July 07, 2017, 01:18:03 PM »
I would extend this problem back to the last 5-10 days of May. I noticed back then a few discrepancies between visual satellite images and NOAA reported snow cover. May be there were "grey" areas also at end of May influencing results?
 
I only have a "but" with June snow cover: in many of the satellital images, the snow cover over land has been showing a "grey" appearance during June, in other words, that it is only a partial or a thin cover with many spots (trees, tundra vegetation, valleys void of ice) showing a much lowered albedo, as opposed to the absolutely white covers during much of May.

Probably that was taken into account.
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meddoc

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Re: The 2017 melting season
« Reply #2634 on: July 07, 2017, 02:21:54 PM »
The Arctic looks very stormy on arctic.io
These Cyclones not only mechanically fragment, tear apart the remaining Ice & then disperse the slush, but also stirring up warmer Waters underneath.
It looks to me that the Arctic is being encroached day by day further.

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Re: The 2017 melting season
« Reply #2635 on: July 07, 2017, 03:03:48 PM »
Rob

A 5.41m km2 September minimum implies an average decline of <50k/day between now and mid-September. We have not seen losses that would support an average of that low a magnitude as yet.

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Re: The 2017 melting season
« Reply #2636 on: July 07, 2017, 03:31:58 PM »

Again this year's theme emerges: A warm wet winter leaving more snow but thinner ice. So, which will dominate: late snow melt or thin ice? We are on the verge of learning.


I believe we are going to get a very clear answer to this question and it is going to surprise us. Not only this but we may have to explore the ongoing impact of a stormy, moist Arctic, very unlike the kind of Arctic we have been looking at.

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Re: The 2017 melting season
« Reply #2637 on: July 07, 2017, 03:46:00 PM »
IMHO, these are the things we need to start accounting for and work to understand the impacts.

1. A generally warmer Arctic
2. A generally stormier Arctic
3. Increased snowfall across the northern hemisphere, particularly in the Fall.
4. Frequent cold air intrusions into the lower latitudes
5. Frequent warm air intrusions into the Arctic

I am sure there are other system wide perturbations that we need to consider.

jplotinus

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Re: The 2017 melting season
« Reply #2638 on: July 07, 2017, 04:07:52 PM »
2016 and 2017 extent measures have been running neck/neck throughout June and into July. 2016 ended up 2nd lowest, jaxa. A visual comparison of worldview for three areas--Beaufort, Laptev/ESS and Kara--show that the two years as of this date had similar demarcations of loss in Beaufort, Laptev/ESS, but very different ones in Kara. There's a lot of ice left in Kara this year that will likely serve to add 10-15k of daily losses starting virtually any day now, thus assuring that 2017 will continue to keep pace with the 2016 rate of decline, through July, at least. That Kara ice is not going to survive.

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Re: The 2017 melting season
« Reply #2639 on: July 07, 2017, 05:25:27 PM »
And here the comparison with 2012. In general terms it seems to agree with the volume differences of PIOMAS.
And last but not least: The Current TOPAZ4-guess for the volume decline for the first half of July
.
There is no general agreement between these images and the link you provided.  4-year old sea ice in 2012 is 5X the average thickness currently found north of Greenland.  I do not see only -500 km^3 delta between 2012 and now.  The Arctic Ocean is ~14 million km^2.

It looks closer to -2,000 km^3  I do not know if 2012 is now understated or if (likely) 2017 is overstated.
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Re: The 2017 melting season
« Reply #2640 on: July 07, 2017, 05:58:13 PM »
That Kara ice is not going to survive.

Absolutely agree. That ice is still masking the real state of the Arctic.
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Re: The 2017 melting season
« Reply #2641 on: July 07, 2017, 06:49:23 PM »
Absolutely agree. That ice is still masking the real state of the Arctic.

This reminds me of Neven's July 3rd post:
SST anomaly on July 1st, 2012 vs 2017:

Looking at the areas of that map that are colder in 2017 than 2012, I wondered how much of the nearby ice is "doomed anyway" this year - sure to melt out even if it takes awhile. Beyond the Kara, is there other ice that can be written off at this point? Like the rubble in and above Fram Strait, unless the drift reverses?

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Re: The 2017 melting season
« Reply #2642 on: July 07, 2017, 07:43:21 PM »
There's a lot of ice left in Kara this year that will likely serve to add 10-15k of daily losses starting virtually any day now, thus assuring that 2017 will continue to keep pace with the 2016 rate of decline, through July, at least. That Kara ice is not going to survive.
While 2016 had a lead in Kara, 2017 has an equally large lead in Hudson.  So, I wouldn't count on Kara melt being sufficient to maintain 2016's rate.  The Arctic basin will determine that.

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Re: The 2017 melting season
« Reply #2643 on: July 07, 2017, 07:50:17 PM »
@subgeometer

at 1C it will snow most often and it can snow up to 4C if the air at altitude is cold enough to give the falling snow a temperature to surivice or if the snowfall is heavy/fast enough to reach the bottom with speed.

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Re: The 2017 melting season
« Reply #2644 on: July 07, 2017, 09:15:46 PM »
Per discussion of Kara ice, it's gotten noticeably darker in the past couple days. Via worldview.

Edit: needs a click now, since I couldn't figure out how to resize it and still have it play on a loop.
« Last Edit: July 07, 2017, 09:30:03 PM by StopTheApocalypse »

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Re: The 2017 melting season
« Reply #2645 on: July 07, 2017, 09:29:14 PM »
Looking at the areas of that map that are colder in 2017 than 2012, I wondered how much of the nearby ice is "doomed anyway" this year - sure to melt out even if it takes awhile. Beyond the Kara, is there other ice that can be written off at this point? Like the rubble in and above Fram Strait, unless the drift reverses?

Everything outside the "asymmetric butterfly" shape with the Laptev bite as an axis, will melt with the possible exception of some parts of the Canadian Archipelago.

Now, how much will this "butterfly" melt? All indicates that the siberian and pacific sides are weak, while the atlantic side will resist more. How far the melt will go depends entirely on the weather of the next 6-8 weeks.
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Re: The 2017 melting season
« Reply #2646 on: July 07, 2017, 09:35:24 PM »
Per discussion of Kara ice, it's gotten noticeably darker in the past couple days. Via worldview.
Reminds me of 'black ice' on a highway bridge (but I won't tell my story).
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Re: The 2017 melting season
« Reply #2647 on: July 07, 2017, 10:17:51 PM »
Per discussion of Kara ice, it's gotten noticeably darker in the past couple days. Via worldview.

Thanks for that animation. Not only darker but fragmenting -- e.g. there's a large floe pretty much centre that blows up.

Extent-wise, my guess is that this doomed ice will first expand somewhat for a few days, then crash in a week or two. The protected right (west) side near the hook in the island looks healthier and will take a bit longer.
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Re: The 2017 melting season
« Reply #2648 on: July 07, 2017, 10:52:11 PM »
Per discussion of Kara ice, it's gotten noticeably darker in the past couple days. Via worldview.

Edit: needs a click now, since I couldn't figure out how to resize it and still have it play on a loop.
Observing that dark ice with the "microscope" of the sentinel hub tool
http://apps.sentinel-hub.com
 i think is so thin it lets see thru to the ocean beneath

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Re: The 2017 melting season
« Reply #2649 on: July 08, 2017, 12:17:21 AM »
@subgeometer

at 1C it will snow most often and it can snow up to 4C if the air at altitude is cold enough to give the falling snow a temperature to surivice or if the snowfall is heavy/fast enough to reach the bottom with speed.

Only if boundary layer temps support that. More often than not in summer there's an inversion and temps aloft are warmer. Best to check 850 and 925 temps for snow vs rain. Surface temps are of limited value this time of year.