ASI 2013 update 5: cyclone time again

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2012 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

July 21st 2013

Due to technical problems, a video will be posted later today or tomorrow.

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Two weeks ago I said: Bye bye, Beaufort. But the ice in the Beaufort didn't really wave back. It retreated somewhat, but much less than I expected after a full week of ideal conditions. At the end of winter the ice was supposed to be thinner there than last year (when it retreated at an amazing pace) and it currently looks extremely mushy out there, individual floes can hardly be made out. But somehow the ice pack is standing its ground in that part of the Arctic.

Nevertheless, with all the easy ice melting out elsewhere, trend lines on extent and area graphs plummeted, and 2013 slashed some of the difference with previous record years 2007, 2011 and 2012. However, with most of the easy ice now gone and ideal conditions fading out in the past couple of days, things have started to slow down.

There's still a lot of melting potential around (and within) the pack, and with a potentially big cyclone forecasted to form in a couple of days, there's no telling what can happen.

Sea ice area (SIA)

Cryosphere Today has had several big melting periods this month (13 century breaks in 19 days), albeit interspersed with some slow days, and so a very high rate of daily decrease (only 2009 comes close) has brought 2013 real close to 2007 and 2011, and the difference with 2012 has been reduced further to a little over 500K.

Here's the graph based on the latest data:

After having taken over 2010, 2013 is now in 4th position. 2012 takes it slow until the end of the month, so depending on weather conditions 2013 could come even closer. I'm expecting a slowdown in days to come though.

Here's the link to my updated CT SIA spreadsheet.

Of course, the SIA anomaly has been dropping as well:Sea ice extent (SIE)

This slowdown is already manifesting itself in the IJIS numbers (in contrast to last year, extent seems to react quicker than area to changes in weather conditions). It looked as if this year's trend line was going to join the cluster of record years soon, but a couple of slow days in the last week has postponed this:Here's the link to my updated IJIS SIE spreadsheet.

Cryosphere Today area per IJIS extent (CAPIE)

With SIE slowing down and SIA speeding up, CAPIE was bound to finally go down (see the previous ASI update for a thorough explanation of what CAPIE is and what it tells us).

Despite patchiness on the Atlantic side of the Arctic CAPIE is still much higher than 2012, 5% to be exact.

Here's the link to my updated CAPIE spreadsheet.

Regional SIE and SIA

Regional graph of the week, taken from the Regional Graphs page:

The melt in the Kara Sea had some catching up to do, and did a lot of that in the past two weeks, as can be seen on this map that Wipneus has custom-made for this ASI update, showing the differences that have taken place since the previous ASI update. Red = ice two weeks ago, open water now; blue the other way around:

That's a lot of easy ice melting out, joined by practically all of the ice left in Hudson and Baffin Bay. There's still some fast ice left stuck against Severnaya Zemlya, that just like the ice in the Beaufort Sea simply refuses to melt out. But given air and sea surface temperatures I'm expecting all of the Northern Sea Route to open up in the weeks to come.

On a side note: according to MASIE the Central Arctic is melting out faster than in previous years.

Sea Level Pressure (SLP)

This animation of Danish Meteorological Institute SLP images clearly shows what happened in the past two weeks: We see how a large high-pressure area moved over the Chukchi and Beaufort Seas, intensified and then slowly faded out, causing ideal conditions for melt, compaction and transport (MCT). This in fact is the best set-up you can have in the Arctic for extent and area numbers to decrease, and was the first such period this melting season, after weeks and weeks of either low-pressure areas dominating (the PAC-2013 causing some delayed MCT as well) or none of both - what I like to call the neither-fish-nor-flesh-set-up - which actually causes things to slow down substantially.

Towards the end of the animation we also see a low moving in, and this low could be doing some interesting stuff if we are to believe the 6-day weather forecast by the ECMWF model (click for a larger version):

Let me show the forecast at the top right for Wednesday July 24th:

Now that's a big cyclone, very, very similar to last year's Great Arctic Cyclone. Except that it comes out of nowhere, and quickly de-intensifies after Wednesday. It will do some damage to the ice pack, but not as much as last year. Note also the high-pressure area over Greenland.

Of course, the forecast can change. If this thing develops like it did last year, you'll be reading about it on this blog.

Temperatures

Compared to surface temperatures two weeks ago, things have been heating up along the Siberian coast, and there's still some heat left in the Canadian Archipelago, but Greenland remains cold:

We see the heat in the waters of the Barentsz and Kara Sea as well. They have really flared up compared to two weeks ago. In fact, everywhere around the ice pack, from Baffin Bay to the Laptev Bite and the Beaufort Sea things have been heating up quite a bit:

Conclusion

As expected, the decrease has been higher than it has been during any July in the 2005-2013 period. 2013 would probably come even closer to the record years, if the conditions conducive to MCT would have stayed in place. But as the weather is switching again, things will probably slow down.

Two caveats though:

1) Switching weather patterns didn't slow down 2012 like they did in previous years.

2) If the cyclone that is forecasted to intensify in the coming three days and stays intense for a couple of days, we could be seeing another bout of flash melting.

I still think it's going to be difficult to surpass last year's records, which would be only logical after the incredibly slow start to the melting season, but 2007 and 2011 aren't out of reach. Mind you, it's still too early to be ruling out new records. Anything is possible, as large parts of the ice pack are in a really bad shape.

Comments

[wayne]

Ostepop: "The weather has been different, but it still seems peculiar that 2013 has had a much wider green fringe compared to 2007,"

No its not, what we have is scattered ice pack melting as opposed to melting/compaction action, quite a different melting season. The Cyclone dominated 2013 summer offers a completely different view as well as thaw system. I don't think it sinks in well when there is less compaction, less blue water doesn't necessarily mean a cooling is taken place. The only advantage or change; sea ice scattering gives a cooler Arctic summer, and a potential earlier freeze-up, but the latter wont happen if this cyclonic activity persists.

Now to add fuel to these thoughts, the North Pacific and Atlantic (even open arctic ocean) has been warming very much lately:

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/gsstanim.shtml

Even the Arctic Ocean:

http://www.ospo.noaa.gov/data/sst/anomaly/2013/anomnight.8.1.2013.gif

Its not only ENSO which causes more over all worldwide thunderstorm activity. And also cloud seeding. The prog for the Arctic: persistent cloudiness. Which onto itself favours melting come late in the season. But the latest High latitude Ocean warming is the in thing right now. A sure bet for surprises, sea ice is a roller coasting.

[Ostepop1000]

Wayne:

At Cryosphere Today, the tendency is that rapidly melting areas go from deep purple, to light purple, to dark red, to light red, to green, and then melt away.

I have been watching the comparison between 2007 and 2013 at Cryosphere today throughout this melting season:

http://home.comcast.net/~ewerme/wuwt/cryo_compare.jpg

And what is striking is that sea ice areas about to melt are always green in 2013 - the thinnest ice.

But in 2007, large areas go from purple (thick ice) to vanished in a day.

Something has happened here that is not due to weather.

It must be due to changes in how ice thickness is measured.

Better instruments?

New algorithms?

[John Christensen]

@Ostepop,

The ice was indeed in a much better condition in 2007, reflected by the colors on CT showing ice concentration.

The difference between 2007 and 2013 is weather:
- 2007 was dominated by high pressures/open skies and therefore a lot of surface water heating, which again melted the ice. An article deals with 'flash-melting' in 2007 in Beaufort due to the heated surface water.
- 2013 is dominated by low pressure systems, which preserves the ice.

So, in a sense strong ice/bad weather and weak ice/good weather both could have the same result, and melting in 2013 could seem similar to that of 2007.

[Neven]

2007 was also a big compaction event, sea ice concentration is much lower now in large zones.

[Ostepop1000]

@John Christensen:

It seems plausible, but what has been special troughout this melting season on Cryosphere Today, has been the tendency of:

2007: Almost no green melting zone.
2013: Wide green melting zone.

2007: Ice melts directly from red or even purple.
2013: ice turns green before it melts.

Look at the maps, starting from the end of May, and you will see the same:

2007: ice melts directly from red/purple
2013: ice turns green before it melts.

Strange but true.

[Ostepop1000]

@Neven:

2007 was a compaction year, but also a year of the great transport out through the Fram.

Little of that this year.

Quite the opposite.

[John Christensen]

@Ostepop,

Have a look at the Arctic air temperatures right now (the picture in the right side:

http://ocean.dmi.dk/arctic/weather/arcticweather.uk.php

You will see that temperatures are around -5C for a large area.

Ice does not melt very fast at -5C.

This is the difference from 2007.

[Ostepop1000]

@John Christensen

When viewing Cryosphere Today's comparison between 2007 and 2003, there is a significant difference throughout the period:

At any time, 2013 has a much wider fringe of green and pink, meaning thinner ice.

And in 2013, ice turns green for before it melts away.

Which is natural, since ice gets thinner and thinner, until it disappears.

But in 2007, ice seems to go directly from red to nothing.

[Neven]

But in 2007, ice seems to go directly from red to nothing.

Because a lot of it got compacted. This year the ice is much more dispersed than in 2007, and so you get more colours. And in the end the CT comparison page shows sea ice concentration. Besides, the CT comparison isn't all that great. Better use the Uni Bremen concentration maps, compared on the ASIG.

[Ostepop1000]

I get your point, Neven.

But:

2007: ice is red before it disappears.
2013: Ice is green before it disapprears.

This happens at all sides of the Arctic ice cap both the atlantic and the pacific side, throughout the polar basin.

The difference can not be due to weather.

It has to be a change of measurments.

Give them a call, Neven.

[Neven]

Give them a call, Neven.

Be my guest, Ostepop1000. :-)

[Ostepop1000]

Fair enough, I will investigate.

[wayne]

Ostepop1000, big multi-year ice appearing to melt in a day was a feature of 2007, but it was an appearance, highly not happening that way. This animation resolution :

http://arctic.atmos.uiuc.edu/cryosphere/multiyear.ice.quikscat.mov

was not that good, but you can see that thinner ice vanished a whole lot more, while thicker ice survived the Beaufort onslaught to a large extent. Purple colour legend depicts extent coverage. either thin or thick. Summer 2007 melt, winds , sea ice momentum and gyre current were aligned to force the remaining pack into a great compaction. To date 2013 purple core roughly depicts the thicker ice, which survived the summer heat a whole lot better. The Gyre current was largely nullified by cyclonic winds, sea ice trying to compact against the current tends to leave the ice scattered.

[Ostepop1000]

Email returned.

No contact.

[Ostepop1000]

@Wayne

Watch the whole melting season of Cryosphere Today.

Where the season of 2007 is compared to 2013.

Pay close attention to the GREEN!

It makes no sense.

[philiponfire]

Ostepop you cannot make direct comparisons between the maps from 2007 and 2013.
they were created from data from different satellites for one thing and there is also the reality of the ice.
ice today is much thinner than it was so there is much more thin ice to record at any given time.
then ice tended to melt at the edges and have a small area of thin ice. today you have thousands of square kilometres of thin ice. do you think that maybe the map might represent those two realities differently?

[John Christensen]

Disregarding the Ostepop comments, I cannot help hypothesizing about the weather events this year and how it compares to prior years, and especially against 2007.

2007:
A lot of compacting of ice combined with extraordinary Arctic highs (other elements contributed as well, but I believe are of secondary importance). The compacting would lead to lots of open water, which then prevented the typical summer-time cyclones from forming (the cyclones feeding from the temperature difference between ice-covered ocean and warmed surrounding lands). Instead highs were formed, which further contibuted to melting.
What may have been a key initiating factor would then be the compacting of the sea ice.

2013:
We had no ice compacting events of significance during spring, so SIA/SIE in the CAB and neighboring seas was high, and combined with early heating of surrounding lands created ideal conditions for cyclones to form, first of these being PAC-2013.
The cyclone would then further spread the ice or at least keep it spread out, where melting at the edges of the pack would otherwise have caused more significant reductions of SIA/SIE.
In turn, the extensive SIA/SIE will keep cyclones forming, until there is no more ice left to spread out, or land temperatures start going down.

While the spreading of the ice is a risky affair in the event a strong high would form, this risk is lessened as the sun is lowering on the horizon, and it could turn out that the flexible/broken ice we have left aided in preserving what is left and thereby extending the inevitable decline.

It will be very interesting to see the next PIOMAS update to show if we are observing the spreading of an ever-thinning layer of ice, or if the relatively low temps have kept melting down to some degree as well.

[johnm33]

Ostepop1000
My amateur way of understanding this is that the compaction takes place on a small scale,look here and you'll see the wind driven eddies are smaller as you go north, and in the far north as you approach the axis of rotation become more or less a blur on the margins. In 2007 with the high pressure, and the wind opposing the ocean circulation large numbers of local compaction events took place. This year with persistent low pressure and the wind reinforcing the ocean currents, the ice is continuously dispersing. Further and I'm much less confident about this, in the compaction events the ice was driven north, from a high energy state in terms of the earths rotational speed to a lower one, and thus tended to melt to preserve equilibrium, this year the opposite is taking place, that is once the inertia imparted by the wind drives the ice too far south it tends to freeze. So what happens when/if we get a high pressure system?

[johnm33]

That should have been here http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsst/nowcast/sst2012090318_2012090100_035_arcticsst.001.gif

[John Christensen]

Amazing development these last few days during the latest cyclone:

http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=07&fd=26&fy=2013&sm=08&sd=01&sy=2013

It seems like the cyclone did not just spread the ice, but that the low temps caused some freezing in the CAB as concentration has gone up on CT - unless the cloud cover is playing tricks on the satellite sensors..

Looking forward to the next update - and then PIOMAS.

[philiponfire]

John Christenson I think that you are misinterpreting the SIA. an increase in area can take place with no extra ice at all.

http://neven1.typepad.com/blog/2010/08/area-vs-extent.html

you are also reading too much into the CT today Maps they are the least accurate of the maps available in my opinion.
try this for a much more accurate visualisation of the state of the ice.
ftp://ftp-projects.zmaw.de/seaice/AMSR2/Arc_latest_yesterday_AMSR2_3.125km.png

finally the current CT SIA figures seem highly suspect they are not following the SIE figures at all. MASIE SIE has dropped every day from day 203 to day 214 after a 4 day uptick.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/masie_extent_sqkm.csv

NSIDC also shows no sign of a prolonged stall.
http://nsidc.org/arcticseaicenews/