The arctic ice melt season has begun, with sharp drop in ice area in the last two days. Ice area peaked at a record low, and ice extent very close to record low.
There is currently a pressure 'dipole' with high pressure over the Beaufort Sea and low pressure (remnants of our recent storm) on the Atlantic side. This has set up the classic drift pattern, with ice flowing down the eastern coast of Greenland., where it will melt out. The very mild conditions over the last 2 months has resulted in structurally very weak ice on the Atlantic side, so it is breaking up and drifting in the wind across a wide area very early in the melt season.
Although still well above seasonal norm, air temperatures are forecast to return to extreme relative warmth in a few days.
Arctic Ice Watch
Moderator: Peak Moderation
The PIOMAS arctic ice volume estimate for March has been posted on one of their data web pages, although their 'official' pages haven't been updated yet.
With the record air and sea surface temperatures, it is no surprise that volume
(20.621 cubic miles) is the lowest on record for March, ahead of 2011
(21.390 cubic miles) and down about 35% from 32.045 estimate in 1979.
Volume peaks annually in April. Ice growth in the month is between 0.6 and 1.2 cubic miles in the records, so the April maximum will also be a record low (previously 22.5) giving a clean sweep between area, extent and volume measures.
With the record air and sea surface temperatures, it is no surprise that volume
(20.621 cubic miles) is the lowest on record for March, ahead of 2011
(21.390 cubic miles) and down about 35% from 32.045 estimate in 1979.
Volume peaks annually in April. Ice growth in the month is between 0.6 and 1.2 cubic miles in the records, so the April maximum will also be a record low (previously 22.5) giving a clean sweep between area, extent and volume measures.
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kenneal - lagger
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Indeed the official PIOMAS figure is slightly higher than the record year of 2011, but lower than in the year of record melt, 2012.
Interesting detail is that the PIOMAS model is assuming thick ice in the East Siberian Sea, an area that has seen unusually warm temperatures through the winter. This appears to be because of the strong Beaufort Gyre this year, where the winds have rotated the ice floes clockwise , leaving the Beafort Sea with very thin and fragmented ice, but the ESS with very thick ice compression ridges, where the ice is several times thicker than surrounding areas. These ridges are too small to be picked up by direct satellite observations, but add significantly to the overall volume.
It is details like this that has made the PIOMAS model the most successful in ice volume research.
Interesting detail is that the PIOMAS model is assuming thick ice in the East Siberian Sea, an area that has seen unusually warm temperatures through the winter. This appears to be because of the strong Beaufort Gyre this year, where the winds have rotated the ice floes clockwise , leaving the Beafort Sea with very thin and fragmented ice, but the ESS with very thick ice compression ridges, where the ice is several times thicker than surrounding areas. These ridges are too small to be picked up by direct satellite observations, but add significantly to the overall volume.
It is details like this that has made the PIOMAS model the most successful in ice volume research.
For the last week or more there has been a stable (very) high pressure system sitting over the Beaufort Sea, at times combined with a low pressure system on the Atlantic side.
This leads to low temperatures but also clear sunny skies, and a very strong clockwise rotation of the ice ( Beaufort Gyre ) leading to widespread cracking of the ice even in the multi year ice north of the Canadian islands. The clear water freezes over, but the ice will be thin and melt easily in the next month or two. It has also lead to rapid transport of ice through the Fram straight to the east of Greenland, although Svalbard has so far remained almost ice free, due to very warm Altantic water currents.
Also north winds in the Bering Sea is driving the ice between Alaska and Siberia south, leaving open water behind, and this ice is almost certain to melt out in the next month.
Sea ice extent remains are record low for this time of year, but area measurements have been complicated by the failure of a satellite sensor used by several different research groups.
So far the weather pattern is very favourable for ice melt. The next 6 weeks will be very important because widespread early melt ponding on the ice in May and June will accelerate summer melt by reducing albedo.
This leads to low temperatures but also clear sunny skies, and a very strong clockwise rotation of the ice ( Beaufort Gyre ) leading to widespread cracking of the ice even in the multi year ice north of the Canadian islands. The clear water freezes over, but the ice will be thin and melt easily in the next month or two. It has also lead to rapid transport of ice through the Fram straight to the east of Greenland, although Svalbard has so far remained almost ice free, due to very warm Altantic water currents.
Also north winds in the Bering Sea is driving the ice between Alaska and Siberia south, leaving open water behind, and this ice is almost certain to melt out in the next month.
Sea ice extent remains are record low for this time of year, but area measurements have been complicated by the failure of a satellite sensor used by several different research groups.
So far the weather pattern is very favourable for ice melt. The next 6 weeks will be very important because widespread early melt ponding on the ice in May and June will accelerate summer melt by reducing albedo.
Another week and very little has changed. Sea ice extent at record lows. Sea ice volume back close to record lows, as reported by the Crysat-2 satellite, backing up the PIOMAS model, but with a large area of thicker ice NE of Greenland and about to be expelled down the Fram straight to melt out in the Atlantic. The primary satellite reporting area is playing silly games again but no-one doubts the real numbers are very low.
High pressure over Beaufort, low pressure over the Atlantic. Temperatures still above average and rapidly rising. Snow cover in NA and Siberia is melting early . Even respected ice scientists and not just amateurs are saying conditions are ideal for a record summer melt.
http://neven1.typepad.com/blog/2016/04/ ... s-low.html
How long will this NH weather pattern last? The gulf stream has stalled and we are stuck in Northerly winds, and an annoyingly cool spring. We have lit the wood burner a couple of times recently.
High pressure over Beaufort, low pressure over the Atlantic. Temperatures still above average and rapidly rising. Snow cover in NA and Siberia is melting early . Even respected ice scientists and not just amateurs are saying conditions are ideal for a record summer melt.
http://neven1.typepad.com/blog/2016/04/ ... s-low.html
How long will this NH weather pattern last? The gulf stream has stalled and we are stuck in Northerly winds, and an annoyingly cool spring. We have lit the wood burner a couple of times recently.
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kenneal - lagger
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10 days since the last update.
Not much has changed in the weather, in that the arctic is still dominated by high pressure, although it has shifted to the N pole and is less intense. Temperatures are still just above normal. Cloud has returned and the Beaufort Gyre has subsided in intensity.
However, the ice is melting with gusto, in the Barents Sea, Beaufort Sea, Greenland Sea and elsewhere. Sea ice extent has been at seasonal record lows for 6 weeks now, melting is about a week ahead of the previous record year, and pulling ever further way. Cracking from the Beaufort Gyre has spread deep into the central arctic, and has just about met up with cracks from the Atlantic side.
It is too early for much melt ponding, but there is already plenty of open water, and snow coverage in Alaska and parts of Siberia are low.
It will now take an unusually cool, cloudy summer for the ice not to reach a record low extent in September (although the last 2 summers were just that).
Ice area measurements still awaiting new/repaired satellite, and PIOMAS volume data is also affected.
Not much has changed in the weather, in that the arctic is still dominated by high pressure, although it has shifted to the N pole and is less intense. Temperatures are still just above normal. Cloud has returned and the Beaufort Gyre has subsided in intensity.
However, the ice is melting with gusto, in the Barents Sea, Beaufort Sea, Greenland Sea and elsewhere. Sea ice extent has been at seasonal record lows for 6 weeks now, melting is about a week ahead of the previous record year, and pulling ever further way. Cracking from the Beaufort Gyre has spread deep into the central arctic, and has just about met up with cracks from the Atlantic side.
It is too early for much melt ponding, but there is already plenty of open water, and snow coverage in Alaska and parts of Siberia are low.
It will now take an unusually cool, cloudy summer for the ice not to reach a record low extent in September (although the last 2 summers were just that).
Ice area measurements still awaiting new/repaired satellite, and PIOMAS volume data is also affected.
The ice continues to melt, and extent drop is now 2 full weeks ahead of the previous record year.
To gain a measure of how extreme this is, ice extent is now 4 standard deviations below the expected value for this time of year, the previous record low being just over 2 standard deviations.
Calibration of an older satellite to replace the defective one measuring sea ice area is on-going, but initial results put the area figures as nearly as extreme as the extent ones, at 3.4 SD
Above freezing air is now entering the Arctic from central Siberia. There are a few early signs of melt-ponding. Open water is beginning to appear off the Siberian coast.
Combined with the extensive cracking above Canada and Greenland, the entire ice sheet is now detached from the shore.
Soon, the thinner ice in the peripheral seas will have fully melted out. Then it will be down to melting in the central arctic, and ice extent decline may (or may not) stall.
The PIOMAS ice volume figure puts April at a tie with 2010 for record low.
To gain a measure of how extreme this is, ice extent is now 4 standard deviations below the expected value for this time of year, the previous record low being just over 2 standard deviations.
Calibration of an older satellite to replace the defective one measuring sea ice area is on-going, but initial results put the area figures as nearly as extreme as the extent ones, at 3.4 SD
Above freezing air is now entering the Arctic from central Siberia. There are a few early signs of melt-ponding. Open water is beginning to appear off the Siberian coast.
Combined with the extensive cracking above Canada and Greenland, the entire ice sheet is now detached from the shore.
Soon, the thinner ice in the peripheral seas will have fully melted out. Then it will be down to melting in the central arctic, and ice extent decline may (or may not) stall.
The PIOMAS ice volume figure puts April at a tie with 2010 for record low.
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vtsnowedin
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I check these out regularly. https://lance.modaps.eosdis.nasa.gov/im ... .terra.4km
http://ocean.dmi.dk/arctic/meant80n.uk.php
Now the primary website source of sea ice extent figures has been off-line for 4 days so far, which is sending the amateur doom-watchers frantic with frustration. A server hardware failure is reported, no fix date given. (Apparently most Japanese IT infrastructure is remarkably outdated - they simply stopped installing new tech about a decade ago, as what they had did the job they needed and they saw no point in spending on upgrading).
Secondary sources suggest that ice extent and area continue to decline rapidly, and are about 10 days ahead of the previous record.
There is now almost completely clear water from the north end of the North West Passage to the Pacific Ocean, a remarkable amount of open water at this time of year.
Temperatures remain marginally warmer than average, and the high Arctic has not had a SINGLE DAY of below average temperatures THIS YEAR.
The weather remains remarkably average, moderately high pressure dominates, relatively warm clear skies, winds favouring export of ice from the central Arctic to the Fram strait east of Greenland, where it always melts out in the warm Atlantic waters.
At this time in 2012 the sea ice extent figures fell off a cliff with unprecedented rapid melt, so the scale of the lead over previous years is likely to decline, but there is still room for steady melt in several areas in the coming weeks. Only the Canadian and central Siberian sides of the Arctic seem to have relatively robust ice.
A significant minority of the usual suspects are predicting an ice free North Pole at some point this year.
Secondary sources suggest that ice extent and area continue to decline rapidly, and are about 10 days ahead of the previous record.
There is now almost completely clear water from the north end of the North West Passage to the Pacific Ocean, a remarkable amount of open water at this time of year.
Temperatures remain marginally warmer than average, and the high Arctic has not had a SINGLE DAY of below average temperatures THIS YEAR.
The weather remains remarkably average, moderately high pressure dominates, relatively warm clear skies, winds favouring export of ice from the central Arctic to the Fram strait east of Greenland, where it always melts out in the warm Atlantic waters.
At this time in 2012 the sea ice extent figures fell off a cliff with unprecedented rapid melt, so the scale of the lead over previous years is likely to decline, but there is still room for steady melt in several areas in the coming weeks. Only the Canadian and central Siberian sides of the Arctic seem to have relatively robust ice.
A significant minority of the usual suspects are predicting an ice free North Pole at some point this year.
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biffvernon
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vtsnowedin
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That is totally in disagreement with the current Canadian ice chart.PS_RalphW wrote:....
.....
Secondary sources suggest that ice extent and area continue to decline rapidly, and are about 10 days ahead of the previous record.
There is now almost completely clear water from the north end of the North West Passage to the Pacific Ocean, a remarkable amount of open water at this time of year.
http://ice-glaces.ec.gc.ca/prods/WIS56C ... 887623.pdf
Also note the temperatures for the last seven days in the table at the lower left corner.
But they have been very close to average for the last fifty days.Temperatures remain marginally warmer than average, and the high Arctic has not had a SINGLE DAY of below average temperatures THIS YEAR.
http://ocean.dmi.dk/arctic/meant80n.uk.php
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