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Lord Soth

I don't think the direction of the beaufort gyre matters that much. What is happening is that the beaufort gyre is huge and is centered near the pole, and has shutdown the transpolar drift.

The ice is not being pushed south, and is not melting. That Gyre must be however grinding that ice into smaller pieces, so when the huge gyre shrinks and move back to the beaufort, the ice will me more conditioned for melting, regardless of what direction its turning.

Andrew Xnn

That NASA photo is fairly interesting. If it was that sunny, maybe that partly explains why 2010 had so much melting at the time.

Wondering if photos are available closer to live time.

Also interesting to see what looks like a cyclonic storm off Alaska.
Didn't know there were all that many storms in the summer.

Account Deleted

Lord Soth/Neven,

All week there has been disagreement between the Russian prediction's and that of PIPS. PIPS has been suggesting some degree of ice export into the Greenland sea

Account Deleted

There is also a fair amount of ice being exported out of the Nares strait - Buoy 7440 appears to have just entered the strait http://iabp.apl.washington.edu/maps_daily_naresstrait.html
so we should be able to see how quickly it get moved out.

Neven

Sepilok, I've added day 188 to the NWP Passage animation.

What is a better sea ice drift forecast to watch, PIPS (updating every day) or AARI (updating every Wednesday)?

Peter

Sepilok, I've been keeping tabs on the ice flow through Nares strait over the past few weeks, mapping position and distance travelled of buoy 7440 on bing maps

http://www.bing.com/maps/?v=2&cp=82.18317450859332~-60.25097924804686&lvl=7&cid=4AF6474AAB468769!116&eo=0

My preliminary estimate is a 480km2 of ice per day passing through the strait at present using 80% concentration, 40km width * 15km/day speed.

~15k a month
extrapolate over full melt season : (may+june+july+aug+sep+oct)= ~90k (km2) ice.
this maybe an underestimate - please correct as you see fit.

Neven

Peter, that's pretty cool. That buoy really got sucked straight into the strait between the 4th and the 6th of July, didn't it?

Do you have any idea how your preliminary estimate holds up against previous years? There probably are numbers in this paper by Kwok et al. but I think it's behind a pay wall. One quote though:

The 2007 area and volume outflows of 87 × 10^3 km2 and 254 km3 are more than twice their 13-year means. This contributes to the recent loss of the thick, multiyear Arctic sea ice and represents ∼10% of our estimates of the mean ice export at Fram Strait.

87K in 2007.

Neven

Hmmm, IJIS is not reporting as of yet. The Uni Bremen AMSR-E daily maps page is also down. It's not a big deal, but something is not right.

Neven

Nope, I was wrong. Another minimal melt: 45,000 square km.

The funny things was I kind of expected it. I don't know if anybody else has noticed this, but I think that the graph is updated before the newest data is communicated. I don't how much before, but I've noticed that when you look at the big version of the graph, you can already see the trend line pointing in a certain direction. Before the low reported melt number was put up, I had already noticed the trend line leveling off another notch.

This is my biggest discovery yet. ;-)

andrewt

Currently 32C in the arctic port of Pevek: http://www.wunderground.com/global/stations/WUHMP.html which should prouce a little surface melt in the East Siberian Sea

DMI's SST anomaly plot for the Arctic is showing a lot of area at 5+C
http://ocean.dmi.dk/satellite/index.uk.php
Anyone know the merits or otherwise of their plots, what the baseline is, and any comparison to recent years.

Steve Bloom

Can anyone tell me if the black dots on this map are melt ponds?

Evilreductionist.blogspot.com

This is an interesting prediction graph for September average sea ice extent that is updated daily:

ftp://ftp-projects.zmaw.de/seaice/prediction

Neven

Steve Bloom, I wouldn't have the faintest idea. The map looks a lot like the one from Uni Bremen, and their site is down...

Steve Bloom

I noticed the similarity too, but don't recall seeing any such thing on the Bremen graphics.

Thanks for that, ER, although I notice that June caused them to go from 4.9 to 5.0, which is the exact opposite of my thinking. *sigh*

Gas Glo

>"Do you have any idea how your preliminary estimate holds up against previous years?"

Don't tell me you didn't look at:
http://nsidc.org/images/arcticseaicenews/20100706_Figure5a.png

Lord Soth

Interesting that the extent and area has decline at a snail's pace; especially when we are entering the two week period with climatic maximun tempertures in the high arctic.

I still believe we are losing ice volume at a high rate, and it is just weather patterns that is masking the actual lost.

I will be glad when they have cryosat-2 up and fully operational, although I don't know if this new sat. can update the volume every day or if it will take days to weeks to get a full pass of the arctic.

It would be nice to have daily or weekly ice volume measurements based on actual data. This will help remove short term weather patterns from the equation.

Account Deleted

The NCEP also show that a slightly warmer than normal SST in the arctic ocean. This should (?) support your idea that we are losing ice volume at a high rate.

Until Neven's site came along I never knew their was so much info out there for the arctic - previously I just use to look at CT and NSIDC - when I had a chance.
Now I come to the office at 5:30 - 6 am and have my morning coffee checking out how the arctic sea ice, arctic temps, buoys, anomolies etc. are going, before organise my field assistant's worksheets and GPS's for the day, before heading into the field at 8.

Neven

I will be glad when they have cryosat-2 up and fully operational,

Me too, although not knowing what the hell is going in, also has a certain charm.

I've updated my graph page a bit, swapped one buoy map for another that shows the the last 2 and 10 days beside the 60-day drift, and I've added the University of Cologne weather map.

Lots of green, yellow and orange in the East Siberian Sea according to Uni Bremen.

Nick Barnes

Peter: that's quite similar to my estimate. It seems to me that the Nares strait can be important in its effect on the Lincoln Sea ice, but I think not in terms of the total ice export through the strait. It's just too narrow for that.
I have been watching and animating the ice north of Svalbard and Franz Josef Land, on and off for the last couple of months. In a normal year, this streams south to the Greenland and Barents Seas, at 10-30 km per day, across an enormous front. The transpolar drift in action. Not so this year, although it is drifting around, and as ice heads south it is breaking up and melting. The ice front is pretty steady, running in a fairly straight line from Nordøstrundingen (the NE cape of Greenland), a little north of Svalbard and a little north of Franz Josef land. I don't know but I suspect that this line may be, or be close to, the uttermost northern limit of the gulf stream circulation. Any ice which crosses this line doesn't last long. The ice inside this line gradually spreads out, but still looks to be high enough concentration to be 100%.

Andrew Borst

Can anyone tell me if the black dots on this map are melt ponds?

Steve,

Looks like they are small open areas -- http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c04.2010189.terra.250m. Seems like anything black is either open sea or so thin that it is virtually melted within the contiguous ice extent. Nice graph.

Neven,

Thanks for upgrading the temperature map.

[fixed the link - N.]

David Klein

Lord Soth | July 08, 2010 at 12:50
I think you are right that sea ice volume is declining at a high rate. Even if this melt season stays within the boundaries of 2007 - 2009, we are bound to see 2007 type melts, or even larger from 2011 onward. I sense a kind of tipping point, where multi-year ice has lost the battle, happening now. A lot of ice volume can be lost without a proportional area decline. Does anyone know why 15% or more was chosen to represent full ice cover? Did ice volume uncertainty play a role in the determination? If an 80% concentration area becomes 60% through wind/current driven spreading, the actual melt is surely masked, similar to aerosols masking the real CO2 warming effect.

Anu

@David Klein Does anyone know why 15% or more was chosen to represent full ice cover? Did ice volume uncertainty play a role in the determination?

I think the whole "sea ice extent" vs. "sea ice area" methods predated the satellites that could measure sea ice volume:
http://nsidc.org/arcticseaicenews/faq.html#area_extent

And remember DMI uses a 30% threshold for their "sea ice extent":
http://ocean.dmi.dk/arctic/icecover.uk.php

Yes, winds could spread out sea ice floes and make the extent larger, but this also leads to faster melting. If the spread happens in July or August, it probably speeds up the melt - the final spreads in September probably just inflate the extent, because melt is just about over.

Neven

From what I can see through the clouds the ice in Melville Sound is totally breaking up. Get your kayaks out.

Steve Bloom

Thanks, Andrew. Maybe it's just that the graphic I linked was high-res enough to show them. Given the mobility of the ice, it would make sense for those small gaps to be present over extensive areas.

andrewt

The Viscount Melville Sound ice bridge has fractured through:
http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c02.2010189.aqua

Gareth

Here's an interesting titbit: Ron Lindsay at the University of Washington has updated his September prediction using late June PIOMAS data: "the predicted extent is 3.96 +/- 0.34 million square kilometers. The R2 value for this predictor is 0.84. which now indicates a high degree of skill in the forecast."
http://psc.apl.washington.edu/lindsay/September_ice_extent.html

Neven

Great tip, Gareth! My web monitoring software hasn't even reported it yet. Ah, I see Lindsay made a new page, that's why.

They don't seem to be too worried by the recent low reported melt numbers, do they?

Neven

I see that Zhang has updated his prediction from 4.7 to 4.8 million square km.

Steve Bloom

Interestingly Lindsay's volume-based prediction has dropped about .5M km^2 for two months in a row. If he keeps that up my wild-ass guess, er, carefullty paramterized estimate of ~3.2 starts to look pretty plausible!

Nick Barnes

Check out the Sound tonight. Beautiful.

Neven

What a huge difference with 2007. I hope tomorrow's image is less cloudy so I can update the animation. Should look pretty cool.

Kevin McKinney

I--and, I'm sure, many others--have been seeing this opening up of the NWP coming--not, of course, that it's fully "open" yet. It reminds me also of what we've just witnessed with Hudson Bay, and how rapidly and thoroughly it melted out, so early in the season.

All in all, it's a very different picture than I've been seeing over the few years that I've been paying closer attention to the melt season. One of my regular denialist antagonists insists on describing 2007 as a "wind-driven" event, and while I reject that as an adequate characterization, I certainly recognize the very high rates of ice transport that contributed to the record minimum that year.

This year is very different; we seem to be seeing more "melting in place"--or such is my perception; what do you folks think?

I'm intrigued, and am very curious to see what happens, and why.

Gareth

Worth noting that Lindsay's projection is statistical, although based on PIOMAS data. Zhang's is a model projection. Meanwhile, the regular Potsdam update has moved out to 5.0. I suspect we haven't seen the end of the summer's drama yet...

Anu

@ Neven | July 09, 2010 at 01:27
I see that Zhang has updated his prediction from 4.7 to 4.8 million square km.

I downloaded the Zhang forecast animated gif:
http://psc.apl.washington.edu/zhang/IDAO/z.gif
opened it in Quicktime, paused on Sep 23, 2010.

There is a big sea ice bridge from the central Arctic Basin to east of the New Siberian Islands. If you look carefully at the colors of this (modeled) sea ice bridge, it is 37.5 cm thick at its northern side, and 37.5 to 50 cm thick at a southern break point.

As the sea ice melts, the Arctic Ocean that was underneath is free to have waves from the winds - these waves might break that entire sea ice bridge free.

Note the sea surface temperatures near melting ice:
http://ocean.dmi.dk/satellite/index.uk.php
(choose Sea Surface Temp (SST) for the Arctic Ocean)
The sun warms up any open water, the warm water melts the ice at the margins of the sea ice sheet (bottom melting), and the warm water cools.
If a big chunk of sea ice bridge drifted into warm water farther from the previous ice melt, it might be gone in a couple of days.

As the ice thins every few years, we might start seeing end of melt season "surprises" like this, that we've never seen before.

Anu

Also, if you pause the Zhang forecast animated gif at July 07, 2010 and study it:
http://psc.apl.washington.edu/zhang/IDAO/z.gif

it matches very well with images of Arctic open water and sea ice extent such as:
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.004.png
(still 07/07/2010 right now - I download these - are these archived online anywhere, the hi-res versions ? Not those blurry lo-res ones)

or
http://iup.physik.uni-bremen.de:8084/amsredata/asi_daygrid_swath/l1a/n6250/2010/jul/asi-n6250-20100707-v5_nic.png

Beaufort, Chukchi, East Siberian, Laptev, Kara Seas and Baffin Bay all match pretty well.

I guess the question is, how well does PIOMAS model the sea ice thickness this summer, and will the next two months unfold close to the prediction...

Neven

Yep, that's what it's all about. Ice thickness and weather conditions. It's probably the latter that is keeping extent from going down faster at the moment (IJIS reports another measly 57K, and the revisions have been pretty big in the past few days).

I wonder what happens when conditions switch again. Unfortunately I still lack the knowledge to be able to analyse the Arctic weather, although I have read up a bit on meteorological stuff.

andrewt

Southerly winds brought a little bit of summer to Alert yesterday reaching a balmy 19C (now 5) maybe helping the large piece of sea ice that broke off in Archer Fiord and will now drift down Nares Strait: http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r03c03.2010189.terra.1km

David Klein

@Anu | July 08, 2010 at 19:06
Thanks for that, it confirms my thoughts. I remain baffled when some at WUWT gleefully claim lower drops in sea ice extent, with less melting. They are decidedly uncomfortable with sea ice volume, searching for 'data' that 'proves' ice volume increasing. Unfortunately for them it is not proxy data, it is here and happening right now. I hope that Cryosat will soon establish sea ice volume as the one and only true measurement. After all, without multi year ice, the arctic will be seasonal.

David Klein

@Neven | July 09, 2010 at 05:46
My gut feeling is that when conditions swing, the melts will be quite big. It is obvious that at present there is no one year ice left to melt. I think that there is a transition to melting thicker ice, which is happening now, hence the slow down. I think that this year the transition is less gradual than in 2008/9 when much of the in between ice thickness was lost.

FrankD

Comparing todays MODIS pix with this time last year, I'm struck by the condition of the ice. Just eyeballing - I could count pixels, I guess :-) - but it looks to me like there is a lot of badly mashed up ice in the Beaufort and Kara Seas, the coast of Baffin Island and the Canadian Archipelago, compared to last year. East Siberian Sea is in better shape than '09. The rest is either obscured or a bit of a toss up.

Take the extent in the Beaufort for example - the area that exceeds the 15% threshold to be counted for extent numbers is only a little lower this year than last. But in '09 most of that area was 80+% ice-covered, where this year there is a much bigger area that is loose, 30-50% coverage. So even if the official numbers are similar there is a clear difference. I'm guessing (and its no more than that) that if the weather favours it, a lot of current extent will let go with a rush - I expect you'll see some big century breaks when and if...

As Andrew mentions, the bridge in Viscount Melville Sound now has broken (the cracks could be seen more than a week ago), so you'd have to think the NWP will clear pretty quickly from here on in.

Lord Soth

Check out:

http://ice-glaces.ec.gc.ca/prods/WIS56SD/20100705180000_WIS56SD_0005069491.gif

A lot of multiyear ice is going to be history, once the winds in the beufort start turning to the south, as predicted by mid month. Until then, the melt in the Beufort will be hamppered by the cooler northerly winds that are blowing.

Neven

as predicted by mid month

Lord Soth, pray tell, where is this predicted?

On CT sea ice area has gone below 1.6 million again. Regional sea ice area: East Siberia Sea is going down hard all of a sudden, Canadian Archipelago down but not so hard, the Arctic Basin doesn't know what it wants.

Nick Barnes

Further cracking in Viscount Melville Sound tonight, and some more visibility although there is still a lot of cloud. There is a coastal lead visible along the northern coast of Victoria Island, following the channel of thin ice which was clearly visible on pictures for the last month or so, across the mouth of Wynniatt Bay and towards Barnard Point, before disappearing under cloud. The natural assumption is that it continues to follow that previously-visible trough the short remaining distance to Peel Point and the Prince of Wales Sound, and that therefore there is no continuous ice barrier anywhere across the NWP. Which is two days earlier than I - rashly, absurdly - predicted on Sunday.

Whatever is going on in the central Arctic Basin - and I do not remember a year in which the Gyre and Drift currents behaved so oddly - this is definitely freakishly early for the NWP to look anything like this.

Nick Barnes

The weather has also worked to shift quite a bit of ice further east in the NWP - in Barrow Strait and Lancaster Sound, where it looks as if wind action has blown the loose floes 50-100km to the south and east in 2 days, and broken up and melted quite a bit. The ice around Resolute, and in Queens Channel, is all broken too.

Gareth

Here's another perspective: the European Centre for Medium-Range Weather Forecasts (ECMWF) forecast for the northern hemisphere. At the moment there's a low pressure system just to the north of the Canadian archipelago and high pressure over Russia - the inverse of the Arctic Dipole. That low is forecast to intensify over the Beaufort Sea into next week and could bring a lot of wind to the region - blowing ice east against the gyre. It'll be interesting to see what that does to the ice. By next weekend, however, the situation reverses. High pressure's back over the Beaufort, and low pressure over Siberia, and the ice might well start compacting a bit. "Century breaks"coming soon? You read it here first... ;-)

Patrice Pustavrh

If you look for weather prediction, here is one interesting site:
http://www.wetterzentrale.de/topkarten/
You may find many different models including GFS and ECMWF. Personally, I look for 850 HPa temperature, which is well corelated to 2 m Temp but it is not so dependend on time of day. Neven, nice blog :).

Anu

The winds might rearrange the sea ice floes (which can cause the 'extent' to expand or shrink a bit, at the margins), and the winds might blow in some warm air or cold, but I think the biggest affect on the summer melt is the clouds. If the clouds are blocking the sunlight, all that open water heats more slowly - if the sky is sunny, that dark water heats up quickly, causing lots of bottom melt of the sea ice "coasts".

http://rapidfire.sci.gsfc.nasa.gov/subsets/?mosaic=Arctic.2010190.aqua.4km
Look at that black water in the Chukchi Sea and the Beaufort Sea, some in the Laptev Sea, some in Baffin Bay. The more days the Arctic waters are exposed to sun, the more the ice will melt in July, August and early September:

http://www.see.ed.ac.uk/~shs/Climate%20change/Data%20sources/Perovic%20ice%20cover.pdf
In 2007, the Beaufort Sea sea ice experienced bottom melting (due to the warm water) of 4 cm per day (average) in August, and peaked at 11 cm/day in the last week of August.
In 2007, there was 2.10 meters of bottom melt in the Beaufort Sea (and only 0.64 meters of surface melt, caused by sunlight and warm air).

Clear skies will cause more sea ice melt than warm air blowing in from the south; and sea ice compaction/spreading is a minor affect (except maybe the last few days of the September melt, which might cause the minimum to jump around by ± 200,000 km sq.)

I think the water temperatures and the sea ice thickness (preconditioning) are the top two factors in the eventual summer minimum. "Arctic amplification" means that as the summer starts with more open water, this water will tend to warm more (in clear skies), causing more melt that summer, preconditioning the ice for the next season, etc. Small changes, but inexorable.

Does anyone know of any studies or sites that talk about percentage cloud cover during a melt season ?

David Klein

I noticed that the DMI graph shows a marked dip back to 2007. Since they use the 30% criteria could this mean that there is a lot of ice between 30% and 15% waiting to emerge?

Artful Dodger

Anu: excellent analysis. I don't think anyone has clearly stated on this blog what was the single exceptional factor that enabled the record melt of 2007. An inflow of warm pacific water through the Bering Straight occurred at the end of the strongest El Nino since the 1980's. This undermined the Sea Ice in the Arctic Basin, leading to a melt season that peaked on Sep 24, the latest date in the Satellite record. Here is the relevant paper:

http://www.agu.org/pubs/crossref/2010/2009GL041621.shtml

This year is shaping up to be very similar. Of course, the Beaufort sea melt is around 10 days behind 2007, due to the late increase in Sea Ice in April 2010. No matter, the heat is on the way, in the way of warm Pacific water. As soon as the Northern Sea Route opens, the Transpolar Drift will deliver double the Heat content of the Sun to the Central Arctic Basin, and we will see a spectacular loss of Sea Ice Extent, and volume.

Here is an graphic of current ENSO conditions (update each Monday):

http://www.cpc.noaa.gov/products/precip/CWlink/MJO/enso.shtml#current

As of June 30, warm El Nino waters have reached 30N lattitude in the Eastern Pac. It's just time now.

Lord Soth

Final numbers are in and July 9th melt is 71K. This is crunch day, Todays melt must be at least 91K to maintain its lead over 2007.

Also for 2010 to maintain its lead for the month of July, it must mantain an average melt of 91K a day for the remainder of the month.

Lord Soth

Oh I forgot to mention, look how loose the ice is, close to the north pole.

http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c04.2010191.terra.250m

Lord Soth

Re previous post: The North Pole is the lower left corner of the above image.

Chartsgraphs.wordpress.com

I have found the Cryosphere Today's long term sea ice area anomaly chart Tail of the Tape difficult to interpret because of its awkward size. I've made a daily anomaly chart that shows the entire record in a single window here.

I'll be updating daily through September. It's viewable from my Arctic Update page.

Kelly

Kevin McKinney

"This is crunch day, Todays melt must be at least 91K to maintain its lead over 2007."

Seems unlikely, doesn't it?

And I note that already on NSIDC for 7/9, the graph shows 2010 "overtaken" by 2007.

Nick Barnes

@Lord Soth: holy cow! That's all broken up very recently, presumably as a result of that weather system which obscured it for a few days. Can this possibly hold together, or resist melting, for two months?

Jung-Ok Choi

Hi!

I'm Choi, Jung-Ok in Korea.
I've been trained as an intern at CML, GIST.

I'm interested in your research of Arctic sea ice.

Actually I should download the extent/thickness of Arctic sea ice and then archive them in GrADS format.
GrADS format means direct binaray data file(.dat or .bin) and meta control file (.ctl).

Where or How I get these GrADS files of Arctic Sea ice extent/thickness?
I tried to search the data at NSIDC (http://nsidc.org/) but I couldn't.
So I need help.

Can you guide me to do that?

My email address is 'ahaphysics@gmail.com'.

Thanks a lot.

Have a good day!

Neven

Welcome, Jung-Ok Choi. On the Arctic Sea Ice Graphs page there are links to several data files on the top right. If you need more you could perhaps comment in the latest blog post (this one is almost 3 years old).

Jung-Ok Choi

Hi, Neven!

I appreciate for your kind reply.

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