2011 Arctic Sea Ice Thread

[Trakar]

I think they're considering MYI as evidence of ice stocks. I also think that all of that rotten ice and melting MYI and all of it rushing through straits may be epistemologically equivalent to our moms saying "don't scratch it, or it won't heal". I'm afraid so, then I won't ask. I think some forecasts are made by opening the window and waving an arm outside after having moistened a finger with saliva ... probably the middle one.

About winds, I gonna track pressures and post here any recent development.

Your efforts would be appreciated!

The Polar Science Center (PIOMAS) http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/ is also showing a strong decline in ice volume.

 

[bobdroege7]

Looks to me like the blender is on puree

http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png

 

[BenBurch]

Bremen shows the difference between this year and 2007 narrowing. NSIDC does not yet, likely due to their running average smoothing.

 

[macdoc]

Melt ponds shine in the Arctic's summer icescape


At a glance, the landscape looks almost tropical. But instead of warm white sands dotted with turquoise lagoons, a frozen sea gives way to freshwater melt ponds in this recent photo of the Arctic ice. As the ice melts in the sun, liquid water pools and deepens irregular ponds.

Researchers from NASA's ICESCAPE mission are studying changes in plankton, water chemistry, and temperature in these unique pools which form only in the summer to evaluate the impact of climate change.

http://www.newscientist.com/blogs/shortsharpscience/2011/07/melt-ponds-shine-in-the-arctic.html

 

[George 152]

Thank-you for the link!
I have been thinking about an arctic visit for a while now, and may try to set up a trip through the NW passage next summer, it'd be a nice chance to write a few personal perspective articles and pieces (tax write-off for a vacation).

As I understand it these tours have been going for at least 10 years.

 

[aleCcowaN]

http://www.newscientist.com/blogs/shortsharpscience/2011/07/melt-ponds-shine-in-the-arctic.html

That image may suggest one of the reasons they don't agree about sea ice extent.

Today coloured satellite images continue to show an almost ice free Hudson Bay. MASIE reports almost 300,000 km² of ice there yesterday. The Canadian Ice Service provides images that joined show this panorama (a situation in the middle, I'd say)

The spread is now more that one million square kilometres. The next three working days should be plenty of new information and disagreements solved.

By the way, one of the many statistical forecasts took sea ice extent every June 30^th from 2002 on, plotted it referred to the minimum sea ice extent of each year, got a regression line and projected this year's minimum according to the extent by June 30^th. They got a bit more than 50% probability of a new record this year. High R². But that's not the way it works, me thinks.

 

[BenBurch]

New (as of 18th) NSIDC Arctic Sea Ice News; http://nsidc.org/arcticseaicenews/2011/071811.html

Arctic sea ice extent declined at a rapid pace through the first half of July, and is now tracking below the year 2007, which saw the record minimum September extent. The rapid decline in the past few weeks is related to persistent above-average temperatures and an early start to melt. Snow cover over Northern Eurasia was especially low in May and June, continuing the pattern seen in April.

<SNIP>

 

[aleCcowaN]

Sea ice extent with concentrations higher than 30% is now above 2007 values for this date, according to the Centre for Ocean and Ice - Danish Meteorological Institute.

About ice extent higher than 15% the values today ranges from 7 to 7.4 million square kilometers. They are starting to converge, but sea ice volume anomaly has not been updated yet for July 15^th. Forecasts for the rest of this month announce colder weather for most of the ice covered areas. But some record high temperature are expected for the surrounding regions. Some 30°C have been announced for Inuvik, some 300 miles south the actual sea ice border today.

 

[Trakar]

Sea ice extent with concentrations higher than 30% is now above 2007 values for this date, according to the Centre for Ocean and Ice - Danish Meteorological Institute...

"...where areas with ice concentration higher than 30% are classified as ice..."

 

[BenBurch]

Extent is currently even with 2007, and the slope has changed, so it may move above the 2007 line. I will be interested to see the volume anomaly in two weeks.

 

[CapelDodger]

Extent is currently even with 2007, and the slope has changed, so it may move above the 2007 line. I will be interested to see the volume anomaly in two weeks.

We shouldn't lose sight of the fact that 2007 minimum extent was a serious outlier, some 20% lower than the previous record (2005, which was itself described as "remarkable" at the time).

 

[BenBurch]

But 2007 was an outlier that we never fully recovered from in terms of volume. That we are at 2007 extent with a MUCH lower volume may be significant over the next few weeks. We'll see what the actual anomaly is, and more will be clear.

 

[CapelDodger]

But 2007 was an outlier that we never fully recovered from in terms of volume. That we are at 2007 extent with a MUCH lower volume may be significant over the next few weeks. We'll see what the actual anomaly is, and more will be clear.

Volume is the crucial measure, of course. Extent is subject to many influences, area is only two-dimensional; the only place they all come together is at zero.

Extent will tend to lag volume until a lot of it is hovering around that 15% area cut-off, after which it will start catching up rapidly.

 

[lomiller]

Hmm thought I already posted this but I don't see it. hopefully I didn't post to the wrong place

From here it looks like the NE passage is open
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png

In this one the NW passage looks like it’s clearing rapidly, but there could be a couple blockages in the NE passage
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png

 

[BenBurch]

This is earlier than in any prior year if the Eastern passage is open.

 

[BenBurch]

Arctic sea ice at record low for July

http://nsidc.org/arcticseaicenews/2011/080311.html

(bolding mine)

Arctic sea ice extent averaged for July 2011 reached the lowest level for the month in the 1979 to 2011 satellite record, even though the pace of ice loss slowed substantially during the last two weeks of July. Shipping routes in the Arctic have less ice than usual for this time of year, and new data indicate that more of the Arctic's store of its oldest ice disappeared.

Overview of conditions

Average ice extent for July 2011 was 7.92 million square kilometers (3.06 million square miles). This is 210,000 square kilometers (81,000 square miles) below the previous record low for the month, set in July 2007, and 2.18 million square kilometers (842,000 square miles) below the average for 1979 to 2000.

On July 31, 2011 Arctic sea ice extent was 6.79 million square kilometers (2.62 million square miles). This was slightly higher than the previous record low for the same day of the year, set in 2007. Sea ice coverage remained below normal everywhere except the East Greenland Sea.

<SNIP>

 

[lomiller]

http://nsidc.org/arcticseaicenews/2011/080311.html

(bolding mine)

On the bright side, the pace of ice loss seems to have slowed dramatically in mid July and we are now close to 2010 levels instead of being below 2007. Still, it’s disturbing to see so much “rotten” melting ice throughout almost the entire arctic.

 

[BenBurch]

Melt rate may not have dropped. I think the pack has no structure and is spreading before the wind.

 

[BenBurch]

Here is the extent average graph from NSIDC, as you can see, we have a obvious trend.

 

[BenBurch]

Here you can see what they are talking about with respect to old ice. There is almost no old ice left in the Arctic. Old ice is the thickest ice, and also the least saline. Also from above-referenced NSIDC article.