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Arctic Ice Watch
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PS_RalphW



Joined: 24 Nov 2005
Posts: 5260
Location: Cambridge

PostPosted: Mon Aug 01, 2016 12:05 pm    Post subject: Reply with quote

Back to the ice.

The melting continues, and the very dispersed nature of the ice is clear here

http://www.iup.uni-bremen.de:8084/amsr2/Arctic_AMSR2_nic.png

Both the Siberian and the North West passages remain blocked, and a
large area of ice is showing signs of becoming detached in the East Siberian waters, something that happened a few yeas ago on a smaller scale.

Sea ice extent is currently in 4th place but area is very close to 2012's record low. The ice to the north of Greenland is showing low concentration, implying the entire ice sheet is drifting north.

The ice edge on the Atlantic side shows an almost linear edge, which reflects the boundary between very warm Atlantic currents and the under sea ridge in that area which leads to any ice drifting into the current quickly melting out.

The sea surface temperatures remain at record highs and there is some evidence from a couple of recording buoys embedded in the ice that this is leading to faster than usual bottom melt of the ice, even if the less sunny weather has reduced top melt.

The forecast is now for high pressure in the Beaufort Sea to return, which should do a lot of damage to the highly scattered multi-year ice hanging on in that area, and the return of the Beaufort gyre should cause the remaining ice to drift compact , helping the the ice extent measure to accelerate downwards. It is still unlikely to catch 2012, becausea powerful summer cyclone happened that year, leading to a very rapid fall in the extent figure.
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kenneal - lagger
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PostPosted: Mon Aug 01, 2016 1:51 pm    Post subject: Reply with quote

From the National snow and Ice Data Centre:-
Quote:
On July 14, Deadhorse, on the North Slope of Alaska on the shores of the Beaufort Sea, saw a record high temperature. The reading of 85 Fahrenheit (through 7 p.m.) broke the record of 83 Fahrenheit set in 1991. It is also also the highest reading on record for any Alaska station within 50 miles of the Arctic Ocean coast north of the Brooks Range.

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PS_RalphW



Joined: 24 Nov 2005
Posts: 5260
Location: Cambridge

PostPosted: Mon Aug 08, 2016 1:47 pm    Post subject: Reply with quote

With about a month to go to the annual ice minimum, the ice melt continues.

A return to high pressure saw a change of wind directions and a fair amount of sunshine, leading to ice melt and compaction and continued strong falls in the ice extent figures.

The PIOMAS ice volume numbers for July were in line with the recent trend, volume narrowly in 4th place.

The ice area figure at this stage is fluctuating sharply day to day because large areas of ice between the pole and east Siberia are widely dispersed, and the satellite sensors struggle to separate the areas that are just above or just below the 15% coverage that qualifies as 'ice free'.

It is clear that the high water temperatures have enabled bottom melt to offset the relatively cloudy weather this summer, and to keep the melting going at close to record levels.

It seems unlikely that we will match 2012 this year, but the weather in the next month will decide if we match or pass 2007 for second place.
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PS_RalphW



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PostPosted: Tue Aug 16, 2016 3:25 pm    Post subject: Reply with quote

A powerful and very wide cyclone is now over the pole and is forecast to last for some days. This is bound to have a significant impact on the remaining ice, with the doomer end of the spectrum anticipating massive flash melting as the widely dispersed ice gets mixed with warmer and/or saltier waters and goes 'poof'. A similar (but more powerful ) cyclone did that in 2012.

It is too early to tell just yet, but an example of 'poof' is this ice monitoring web cam

before

http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=327.0;attach=34514;image

after

http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=327.0;attach=34544;image

Taken 13 hours apart.
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PS_RalphW



Joined: 24 Nov 2005
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PostPosted: Mon Aug 22, 2016 4:13 pm    Post subject: Reply with quote

The cyclone has blown through, although a second one is brewing. The frequency of these summer storms seems to be increasing, possibly due to the rapid early melt of snow cover on surrounding land masses increasing the temperature differential betwwen the continental air and air above the arctic ice, which remains close to 0C as long as the ice cover remains.

The cyclone does seem to have caused relatively rapid melting in the widely dispersed ice, and dispersed the ice further, not least pushing ice south on the Atlantic side, risking significant melt as it enters warmer water and the Fram straight, where ice 'goes to die'.

However, it also cooled the air somewhat, and this late in the season almost all melting is bottom melt. In the last couple of days the rate of melt has slowed again, and extent (and area?) is just behind 2007 in third place. It seems impossible now to catch 2012.

About 3 weeks to the average minimum extant date. Then the rate of melt in the remaining peripheral ice falls behind the rate of new ice formation near the North Pole. This year there is a lot of peripheral ice, but a lot of holes in the ice close to the North Pole. Not clear how this will affect the late season melt numbers.

The North West PAssage is still blocked at the north end, but may yet clear. The next summer cyclone may speed up the rate of melt again. Or not.

The most interesting data still outstanding will be the PIOMAS ice volume numbers, but as these are partly modelled, there will always be questions
on how well the model reflects the real ice conditions, which are far more dispersed than seen before.
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PS_RalphW



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PostPosted: Thu Sep 01, 2016 6:44 am    Post subject: Reply with quote

We are nearly at the end of the melting season but the melting continues apace. Most measures of ice area and extent put 2016 in second place behind 1012 for this date, and rapidly approaching 2nd place for the summer minimum.

The long sequence of cyclones has been replaced by a huge dipole, with high pressure over the Beafort Sea and a powerful low on the Atlantic side. THis is causing a lot of ice compaction towards Greenland, an area of multiyear ice the size of Svarlbard to be pushed into the Fram strait, where it will melt out, next year if not this, and an arm of open water to extend up to 86% North towards the pole. The ice from the pole towards Siberia is increasingly fragmented, and the arm of ice extending towards eastern Siberia is now little more than a narrow ribbon of rapidly melting floes.

http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1493.0;attach=35489;image

This is what a dieing ice sheet looks like.
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vtsnowedin



Joined: 07 Jan 2011
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Location: New England ,Chelsea Vermont

PostPosted: Fri Sep 02, 2016 11:45 am    Post subject: Reply with quote

PS_RalphW wrote:
We are nearly at the end of the melting season but the melting continues apace. Most measures of ice area and extent put 2016 in second place behind 1012 for this date, and rapidly approaching 2nd place for the summer minimum.

The long sequence of cyclones has been replaced by a huge dipole, with high pressure over the Beafort Sea and a powerful low on the Atlantic side. THis is causing a lot of ice compaction towards Greenland, an area of multiyear ice the size of Svarlbard to be pushed into the Fram strait, where it will melt out, next year if not this, and an arm of open water to extend up to 86% North towards the pole. The ice from the pole towards Siberia is increasingly fragmented, and the arm of ice extending towards eastern Siberia is now little more than a narrow ribbon of rapidly melting floes.

http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1493.0;attach=35489;image

This is what a dieing ice sheet looks like.

The equinox is fast approaching and things will begin to firm up soon. The weather at Alert Canada is already becoming winter like.
https://weather.com/weather/tenday/l/CAXX0829:1:CA
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PS_RalphW



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PostPosted: Tue Oct 18, 2016 8:12 am    Post subject: Reply with quote

The ice reached minimum extent and area relatively early in the season, and there was rapid refreeze close to the pole the rest of September (Any other year the ice has been nearly solid that close to the pole so there hasn't been any open water to refreeze).

Since the first of October, the refreeze has nearly stalled as the open water further south has more heat to release and is more mixed with deeper , saltier water by the summer storms. Area has now fallen back below the 2012 figure for this date, and is currently in second place.

September PIOMAS volume came in narrowly in third place. Thickness maps show that the ice in the central arctic has been spread around and further south than usual. The normally fast thick ice pushed up against the canadian arctic islands was pushed south between the islands and into the North West Passage which failed to completely clear as a result. There is a high probability that this ice will melt out next year.
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Catweazle



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PostPosted: Thu Oct 20, 2016 9:40 am    Post subject: Reply with quote

Thanks Ralph .
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PS_RalphW



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PostPosted: Mon Oct 24, 2016 11:51 am    Post subject: Reply with quote

Ice extent remains at record low for time of year.

This image goes a long way to explain why.

https://pbs.twimg.com/media/CvQeFLbVUAEFX4z.jpg:large

We appear to be performing this simple experiment on a near global scale.

http://www.nims.go.jp/water/temp_water.html
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kenneal - lagger
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Joined: 20 Sep 2006
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PostPosted: Mon Oct 24, 2016 7:02 pm    Post subject: Reply with quote

PS_RalphW wrote:
Ice extent remains at record low for time of year.

This image goes a long way to explain why.

https://pbs.twimg.com/media/CvQeFLbVUAEFX4z.jpg:large

We appear to be performing this simple experiment on a near global scale.

http://www.nims.go.jp/water/temp_water.html


If you fitted a curve through those points on the graph I reckon it would show an exponential increase in the temperature rather than a linear one. Scary!!
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johnhemming2



Joined: 30 Jun 2015
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PostPosted: Mon Oct 24, 2016 9:41 pm    Post subject: Reply with quote

Possibly at a power in excess of one (ie non linear), but not exponential.
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PS_RalphW



Joined: 24 Nov 2005
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PostPosted: Tue Nov 01, 2016 1:02 pm    Post subject: Reply with quote

Arctic temperatures remain at about 8C above seasonal normal, at about -11C above 80 degrees North.

Sea ice extent and area growth has entirely stalled, at about 7M Km2

If you average daily sea ice extent figures over the previous 12 month period, then the last 12 months is now at an all time low of 9.8M Km2 , just below the 2012 figure. The daily extent figure is now more than 0.5M Km2 below previous record.

Strong winter storms have kept the skies cloudy, and churned up the remaining open waters for several weeks now, mixing up the cold surface waters with warmer water below, and preventing surface ice from forming. Sea surface temperatures are also 8C above seasons normal, and this represents a massive amount of excess energy.

Just as it is warmer sea water that is melting the Antarctic ice shelves from below, so it is preventing arctic sea ice refreeze.

The Antarctic sea ice extent winter maximum was also early and low relative to recent years.
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PS_RalphW



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PostPosted: Thu Nov 03, 2016 11:30 pm    Post subject: Reply with quote

Here is a graph f 20 years of global sea ice area.

http://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=1457.0;attach=37899;image

As the original poster said, guess which line is 2016....
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PS_RalphW



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PostPosted: Tue Nov 15, 2016 7:31 pm    Post subject: Reply with quote

The arctic 'winter' continues.

Extent. area and volume all at record lows.

Air temperature anomaly is off the scale.

17C higher than long term trend, only -8C over most of the arctic.

One report of the north pole being above freezing.

http://ocean.dmi.dk/arctic/meant80n.uk.php
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