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Stevemosher.wordpress.com

Nice work neven.

Artful Dodger

Hi Neven,

Thanks for reviving the discussion begun by
Artful Dodger | October 08, 2011 at 21:05
... since Typepad.com doesn't link properly to multipage posts, it will suffice to reproduce those comments here:

________________

Hi Bob W,

The 2007 sea ice retreat was made exceptional by warm water inflow from the Pacific to the Arctic. Tethered Buoys in the Bering Strait measured ~4 petajoules of heat entering the Chukchi sea. This is twice the normal heat influx, and equal to total solar insolation for the Chukchi sea over the course of the melt season.

Look at the distribution of sea ice throughout summer 2007. There is a clear focal point to the melt, the source of the heat bloom is the Bering Strait.

This paper provides more details (the AGU introduction is provided 2nd below):

RA Woodgate, T Weingartner, and R. Lindsay (2009) "The 2007 Bering Strait Oceanic Heat Flux and anomalous Arctic Sea-ice Retreat", Geophys. Res. Lett., 37, L01602, doi:10.1029/2009GL041621.

AGU: "Heat from Pacific stoked Arctic melting"

"The causes of the 2007 record-breaking Arctic sea ice loss are not well understood. To investigate the source of the heat that melted so much ice, Woodgate et al. study the role of heat transported to the Arctic from the Pacific Ocean. The authors use observations from in situ moorings and satellite sea surface temperature measurements to quantify the heat flux through the Bering Strait into the Arctic. They find that a substantial amount of heat is transferred through the Bering Strait and that this amount is highly variable from year to year. In 2007, both the amount of water flowing through the strait and the temperatures were at record highs, the authors report. They note that the 2007 heat flux through the Bering Strait was twice the 2001 heat flux and was enough to account for a third of the Arctic sea ice lost in 2007."

What I have not seen yet is any discussion as to the cause of the exceptional heat transport in 2007. I wonder if it was associated with the strong El Nino that year? If so, is this a common pattern for other El Nino years, and should we expect a recurrence during the next El Nino?

Given the weak state of Arctic sea ice in 2011, and the near total loss of MY sea ice, another +4 PW Summer heat influx from the Bering strait could well spell the first ice-free Fall.

Neven

Or will these holes in the ice pack in the Beaufort Sea and just to the north of Wrangel Island play a role as well?

BTW, I meant those smaller holes all over the place, not the polynya right behind Wrangel Island, which is a regular feature.

Given the weak state of Arctic sea ice in 2011, and the near total loss of MY sea ice, another +4 PW Summer heat influx from the Bering strait could well spell the first ice-free Fall.

Absolutely. Given the developments on the Atlantic side of the Arctic, and the general state of the ice, another summer with peak heat (and volume) influx through Bering Strait, and we will approach that final million of area/extent fast.

What I have not seen yet is any discussion as to the cause of the exceptional heat transport in 2007. I wonder if it was associated with the strong El Nino that year? If so, is this a common pattern for other El Nino years, and should we expect a recurrence during the next El Nino?

ENSO, PDO... I will probably do a piece on this if I can find enough info. Here's a good March 2011 article from Climate Central.

Misfratz.wordpress.com
This year's ice in the Beaufort Sea clearly isn't any stronger than it was in previous years. We had already received a hint when the NSIDC released ice thickness data from IceBridge flight missions over parts of the Beaufort Sea, and the current big polynya and very low ice concentration there seem to confirm that this region isn't going to put a brake on this year's melt.
Neven, thanks for posting about this, as it was something I was wondering about.

The open water in the Beaufort Sea is incredibly hot. Above 10C in some areas, and a full 8C warmer than climatology - completely off the scale of the OSTIA SST anomaly plot. So I was expecting that the ice extent would have declined faster than it has in that area.

The arc ice thickness (from your daily graphs page) and the Russian plot you cite above, both suggest that this is partly because there is thick multi-year ice on the edge of this open water, slowing the decline in ice extent.

So perhaps the somewhat thicker ice and high SSTs are acting to cancel each other out, so that the extent decline is neither particularly slow or particularly fast in the Beaufort Sea.

Christoffer Ladstein

Wind has been picking up last 36 hours north of Greenland, according to buoy 4, an indication of increasing export rate through the Fram strait?

Also very hot temps and some decent winds in the Pevek-Tiksi- Zaliv Gedenshtroma triangle; might be the extra push needed to churn and melt the somewhat thicker ice over there.

Though I'm puzzeled by the combination of socalled thicker MYI and the seemingly smashed up ice, just holding together for no other reason than "where are we else to go"!!

The best melting weather for ice & snow is a combination of wind and rain...

BTW, Good work as always, Neven! Don't you go for vaccation soon?

Seke Rob

[ot]On a side note, like the AARI map projection from the Russia/Siberia 90th east angle much better than any other for a broad good [wide] screen filling view.[/ot]

Neven

So perhaps the somewhat thicker ice and high SSTs are acting to cancel each other out, so that the extent decline is neither particularly slow or particularly fast in the Beaufort Sea.

I think I more or less agree. On the one hand, that polynya is quite big when compared to previous years. On the other hand, there is still a lot of ice hugging the coast. But I was expecting more resistance in the Beaufort Sea after this winter.

Don't you go for vaccation soon?

I'm going at the end of August. Still have to find a way to make sure I have a good Internet connection there. Wouldn't want to miss the minimum, now would I? What kind of a holiday would that be? ;-)

Josh

Greenpeace's Arctic Rising campaign: Use your creativity to confront Arctic destruction - and earn points. http://rising.savethearctic.org/en/arctic-fox/4fe3d8371d4a1d0001000552

Bob Wallace

We've got some hot happening right now in the Northwest Passage area. Temps are running well above average highs.

Chukchi temps are running in the normal range.

(Just watching the NWP/Eastern Passage race....)

Paradoxnl.wordpress.com

Neven, very nice overview!

According to GFS in about a few days the weather will turn significantly cooler in large parts of the Chuckchi Sea and the East Siberian Sea.
Seen whether this will restrict the speed at which the ice melts there. (Assuming the weather will become cooler).

Neven

Indeed, Paradox. ECMWF also has a big low-pressure system taking over. We're going to see a big lull in melting, just like we saw in 2010 and 2011.

I've added an update to this post. It seems the thick ice in Beaufort and Chukchi are keeping Shell from doing exploration drilling.

Peter Ellis

Regarding the update: consider the source. It's a press release from Shell - they have a vested interest in spinning any and all delays as being due to the ice conditions. After all, if the ice is nice and thick, then global warming isn't happening, which must mean it's safe to prospect for more oil, right?

If you look at non-Shell sources, you'll see that ice isn't the only reason for the delay. Another factor is that their emergency barge wasn't up to scratch and hasn't yet been given the necessary performance certificate.
http://fuelfix.com/blog/2012/07/06/coast-guard-repair-order-could-delay-shell-arctic-drilling/

Account Deleted

Neven
"We're going to see a big lull in melting, just like we saw in 2010 and 2011."

A very important factor in the speed with which Atlantic side Arctic will melt.

While this melt is close to the record.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/r11_Central_Arctic_ts.png

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/r06_Barents_Sea_ts.png

I keep thinking that PIOMAS model shows the correct data.

If in September in the Arctic will be only 2500 km3 of sea ice, it will mean a low area - 1-2 million km2.

Account Deleted

http://neven1.typepad.com/blog/2012/05/if-only-i-were-smart.html

From the data of NASA Ice Bridge can be found that the average ice thickness above 80 degrees north latitude off the coast of Greenland and Canada's 3.5 meters. During the summer melt of about 1 meter of ice. In September, will be 2.5 meters. The area of the ice about 1 million km2. So the volume will be equal to 2500 km3. The remaining ice to melt this summer (in theory). Although if the thickness of the remaining ice would be 10 cm, the volume of the remaining ice would be 300-400 km3.

Werther

Paradox, Neven,
Nothing is as it seems. That’s probably why you chose the nickname. What you hint at could very well be the beginning of the El Nino cover-effect. It could save the Arctic Basin ice. But the season can still pan out on 3,7 MK extent minimum. IMHO positive AO and low SLP doesn’t produce the results we knew a couple of years ago. The mid July lows bring SW winds over the Kara and Laptev Seas. Perfect for the Atlantic side to succumb to the high SST’s.
For today: watch how transport into Nares Strait is beginning in the Lincoln Sea. Not far from there, the big high is ripping the pack maze north of Ellesmere in SW direction.

Rob Dekker

What a great and thorough overview again, Neven. Thanks !

Regarding the Chukchi, your argument of the harsh winter, leading to thicker ice, the low temperatures in the Bering, and the albedo effect working both ways (early low extent amplifies ice loss later in summer, but early high extent reduces ice loss later in summer) are compelling.

Still, now that the melting season is in full force, I wonder how much the reduced Being heat influx (10 TW 'anomaly') really matters in the big picture these days. For example, the Northern Hemisphere June snow anomaly alone adds about 1000 TW heat influx w.r.t. a few decades ago, and even if only a small amount of that heat makes it to the Chukchi, it could overwhelm the ocean heat influx.

Either way, the Chukchi seems to run only 50 k km^2 behind 'long-term-average' (about a week) schedule and some 150 k km^2 (three weeks) behind 2011.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.10.html
Since the Chukchi was ice free for 2 months last year, this may simply mean that the Chukchi still has a 150 k km^2 "piggy bank" w.r.t. last year, which it will give out later.

Beyond that, the 'stronghold' may have to come from the Arctic Basin, where the battle between the positive anomaly from the West and the negative anomaly from the East would have to be fought.

It's going to be (again) a very interesting second half of the melting season...

Rob Dekker

Regarding the possible link between El Nino events and Bering SSTs, at least according to Neven's graph, 1998 holds the record for lowest SST. And we all know that that year was marked by a 'super' El Nino...
I did not do a correlation analysis, but I suspect that the El Nino - Bering SST correlation is low.

Kevin McKinney

Hey, I didn't realize that clicking on specific regional graphs gives you, among other things, a long-term graph. Here's the one for the Archipelago:

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.12.html

Call it a not very well-hidden decline!

Clicked on it for the larger image--I was intrigued by the 'recovery' in anomaly for the CA, which I'm sure is a matter of ice being transported *through* the CA.

Neven

Thanks, Rob. I agree with what you say. In fact, I'm not sure at all about what is going to happen. I'm just basing myself on what I've learned from the last two melting seasons.

But if the PIOMAS volume numbers are more or less correct, warm water inflow from the Bering Sea may not be needed to break records. And like I say at the end of the post: those holes in the ice pack.

We are now going to get at least a week of dominating lows. I expect a lull in area/extent decrease, but am curious to see how the ice pack is going to look 10 days from now.

Clicked on it for the larger image--I was intrigued by the 'recovery' in anomaly for the CA, which I'm sure is a matter of ice being transported *through* the CA.

Kevin, if I've interpreted you correctly, you refer to this year's anomaly shooting back up to the ling-term average, right? This anomaly was caused by massive melt ponding all over the Archipelago, fooling the satellite sensor (happened more often in the past few years). But the ice is holding up pretty well so far, and so the anomaly shoots back again, with melt ponds draining, etc.

What makes the NWP interesting to me this year is that while for instance the ice arch in Lancaster Sound held up very long (until yesterday) it was actually stabbed in the back by melting and disintegration taking place on the inside.

maltose

Have you noticed the ARC drift maps for the next week, Neven? Right out the Fram. Might not cause melting, but that might cause trouble for the pack in the long run this year.

Kevin McKinney

"Kevin, if I've interpreted you correctly..."

Neven, it's not clear to me if we are on the same page here or not. I'm referring to the lower graph on the page, the one tracking just this year's anomaly. There was an abrupt drop about halfway through June, followed by a sudden recovery to above the mean, then a drop down to average, which is where it is now.

Is that what you mean, or were you talking about the multi-year graph?

Account Deleted

Hi Kevin,

That is the graph Neven is talking about and the 'recovery' is due to the loss of melt ponds and the problems they cause for the passive microwave sensors - this is what Bill Chapman at CT said:

In the meantime, at least part of what could be causing the apparent discrepancy is the problem the passive microwave sensors have in determining sea ice concentration from melt ponds. This time of year, this issue is particularly problematic as the melt season is in full swing in the southern parts of the Arctic. I've seen cases where it looks like the passive microwave derived sea ice concentrations (such as ours) underestimate sea ice concentration by up to 20%. From what parts of the CA I can see in the latest MODIS that are mostly ice covered, it looks like it is very slushy and has lots of melt ponds. These areas show up with a grey and/or bluish tint in the full color MODIS images. Another issue that can cause underestimation of the concentration in passive microwave products is cloudiness, especially optically thick clouds. My guess is that there is some open water already forming in the CA and it is obscured by clouds that we just don't see right now, coupled with artificially low concentrations from the melt ponds and clouds. My guess is also that this heavily melt-ponded ice is not long for this world.

Account Deleted

It also appears that ice is also starting to move thru the Nares strait - if you compare yesterdays and todays image

Christoffer Ladstein

Beringstrait is Heating Up! Take a look at DMI's anomaly map:
http://ocean.dmi.dk/arctic/satellite/index.uk.php
And compare with just 2 weeks ago!

Amazing how hot water many places, close to the iceedge.

Bobtisdale.wordpress.com

Nevin, I look forward to your discussion of Bering Sea sea surface temperatures.

Regards

Mdoliner43

I wonder if anyone has looked at the Oslo science conference. In particular this talk by David Barber:

http://video.hint.no/mmt201v10/osc/?vid=55&ti=4

He found that much multi-year ice was completely rotten.

Neven

Beringstrait is Heating Up! Take a look at DMI's anomaly map:

Indeed, Christoffer. Let's see how this develops, as the red on the DMI SST anomaly map can quickly appear, disappear and reappear. There was some red and orange in the Bering Strait region a couple of weeks ago as well.

But this time I'm also seeing it on the other SST anomaly maps on the ASI Graphs page.

Christoffer Ladstein

Mdoliner:
That conference being 2 year old, but "the rotten MYI" phenomen was debated on this blog, just as the Polarstern crossing the Pole July/Aug. also more or less concluded that the state of MYI is both thin (1-1,5 meter) and pretty rotten.
With that as background curtain we all await what Polarstern is up to this season!You may track the whereabouts of the german scientific ship and the frequent air and seatemps they are doing. Just this morning west of Svalbard they reported of -2,4 C, must be pretty much the coldest spot in the Arctic region lately!
http://www.sailwx.info/shiptrack/shipposition.phtml?call=DBLK

Neven:
WiFi is "almost as important" these days as a sucessful harvest back in the Viking era in Greenland 900 years ago... (One might speculate how fragile our community would be in case of a sudden temperaturedrop or rise of 2-3 degrees!? )

Christoffer Ladstein

At Churchill, Manitoba,Hudson Bay, "Polar Bear Capital of the World", they have today been reporting 31 C for 5 consequtive hours, just "smashing" the record maximum temp for this date, set 2011, with roughly 11 C!!
And they got Polar bears at that place...almost unbelievable that is. Someone call 911...

AmbiValent

On the DMI temperature map almost the whole arctic is shown at >0C levels. But in a few areas sometimes <0C levels are reached, and these areas always seem to have wide cracks between the floes - could that be excessive melting driving the temperature down to the freezing point of ocean water?

Christoffer Ladstein

One last note...
Todays surface pressure map from DMI...
http://ocean.dmi.dk/arctic/weather/mslp_latest.big.png
...show clearly 2 strong lowpressures going on and both are easily visible and refound on the lance-modis map!
http://lance-modis.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic.2012193.terra.4km

That's what I call everyday Art!

How often does such lowpressures take place in the Arctic during the summer? And will they also be an extra meltdown force, churning up the fast ice, pushing it around, mixing in saltwater in the snow and also perhaps leading both hot air and water from more southern latitudes into the colder Arctic, north of 80 degree?!

AmbiValent

(edit: I meant the 2m temperature map)

Janne Tuukkanen

I think cyclones in polar regions are mostly relatively weak and short lived. But who knows, if SSTs will rise, we could see some interesting stuff, like: "Arctic storm Andrew developing eye on North Pole."

AmbiValent

CT appears to have reported a double century (-240k), with the new area of 5.358 m.

And on the concentration image, areas with >75% ice seem further on the retreat towards the Pole.

Jim_pettit
AmbiValent: CT appears to have reported a double century (-240k), with the new area of 5.358 m.

Correct. That's the the second largest one-day decrease this year. That area of 5.358 million is lower than the minimums seen in 1979, 1980, 1983, and 1986. (2012 is safely in first place for the time being, more than half a million square kilometers ahead of second place 2011.)

Going, going, going...

Yowza...

Seke Rob

Someone posted somewhere [the poll thread IIRC], seeing the slope not being so steep anymore...

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

Continue to feel 'twas missing the wink smiley with that comment. NSIDC seems close to 4 Std.Dev. How strong is the hold on the straw?

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