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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/

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