Arctic Ice Discussion (The Melt)

[The PIT]

Blimey we've beaten the 2007 record already that's a sudden drop off.

[BornFromTheVoid]

Of course PIT, it's lowest on record for the time of year. Also, last years minimum was lowest on record for sea ice area, so the 2007 record stands only for extent (depending on what site you follow I suppose).

Edited June 4, 2012 by BornFromTheVoid

[BornFromTheVoid]

The ncep monthly time series has updated to include May and it was the 2nd strongest positive dipole on record (since 1948), with 1990 being the only year stronger, and it was the 2nd strongest April-May combination with 1990 being the only stronger one.

I suppose a bit of perspective on that, is that at this time in 1990, the sea ice area (for June 2nd coming off the back of the strongest May dipole on record) was only 200,000km2 lower than this year which is quite impressive and by far the lowest on record at the time. It wasn't until 2006 that a lower ice area was recorded for that date. Still, plenty of other factors at play so the dipole can't take all the blame!

The mean low was significantly deeper in 1990, causing a much stronger pressure gradient than in 2012.

I kept the scales here the same to show the differences between the 2 Mays

1990 & 2012

[stewfox]

Of course PIT, it's lowest on record for the time of year. Also, last years minimum was lowest on record for sea ice area, so the 2007 record stands only for extent (depending on what site you follow I suppose).

Yes too many sites lots of different data

IJIS (which use to be standard default on this thread years gone by) shows no cause for alarm

http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent_L.png

[jonboy]

Yes too many sites lots of different data

IJIS (which use to be standard default on this thread years gone by) shows no cause for alarm

http://www.ijis.iarc...ce_Extent_L.png

I agree it is very difficult to know if you are comparing eggs with eggs or whether they are hen's eggs and duck egg's.

Modern technology continously changes the way measurements are made with little or no effort to explain how they differ over time. Thus I am not overly worried about so called loss of ice and firmly believe we will see a recovery over the next 5/10 years.

Just an aside if people want to see how these differing measuring techniques produce different outcomes just look at the Laymans sunspot count site.

[BornFromTheVoid]

Yes too many sites lots of different data

IJIS (which use to be standard default on this thread years gone by) shows no cause for alarm

http://www.ijis.iarc...ce_Extent_L.png

The IJIS's current and previous days extent are getting adjusted a lot, so it seems a bit pointless using it for daily analysis when other extent data doesn't vary as much.

The current sensor they use has a much lower spatial resolution than the amsr-e sensor used from 2002 to last year, and with a much bigger "pole hole", so misses more of the ice.

It's still valid of course in it's own right, but being such a different sensor to the last one, the comparisons with previous years might not be as accurate as other extent sources now such as the nsidc which are more consistent.

[cooling climate]

Yes too many sites lots of different data

IJIS (which use to be standard default on this thread years gone by) shows no cause for alarm

http://www.ijis.iarc...ce_Extent_L.png

Yes the Arctic ice is holding up quite well at the present time and I will plumb

for a min of above 5 million this year.

Edited June 5, 2012 by pottyprof
Removed the unnecessary comments

[John S2]

Yes the Arctic ice is holding up quite well at the present time.

Extent may currently be similar to or higher [depending on which source is used] than some recent years, but volume is at record low [see link] which means the ice is thinner. It is therefore more vulnerable to melt.

http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2_CY.png?%3C?php%20echo%20time%28%29?

[Iceberg]

Yep if the 3rd lowest extent on record and the lowest volume on record is holding up well he shows up the river without a paddle we are...

Generally i am staying away from this thread as bftv is doing a very good job and the facts and figures speak for themselves.

[Gray-Wolf]

Nice to see you pop in though Ice!

As for the facts speaking for themselves then look again at this thread since March!!!

Some folk do not seem to care for the facts it would appear?

Not only the lowest ice mass but some sea areas bereft of ice throughout the freeze season!!

Still, not to worry areas well outside the basin held ice (due to arctic plunges driven by low ice levels) so all looked well on the 'extent' charts (for those not knowing what they are looking at!).

To Ice(cap) it all we already have predictions of above 5 million extent come the end of melt season???

I'd advise such punters to look out for the ice free geographic (and magnetic?) Pole come mid Aug this summer. Lots of late formed drift ice over there atm and the 'top melt' part of the season about to start in earnest!

[BornFromTheVoid]

Cheers Iceberg!

The NSIDC May Analysis is out now http://nsidc.org/arc...-below-average/

After reaching near-average levels in late April, sea ice extent declined rapidly during the early part of May. The rest of the month saw a slower rate of decline. Ice extent in the Bering Sea remained above average throughout the month

Overview of conditions

Arctic sea ice extent for May 2012 averaged 13.13 million square kilometers (5.07 million square miles). This was 480,000 square kilometers (185,000 square miles) below the 1979 to 2000 average extent. This May’s extent was similar to the May 2008 – 2010 extent, but it was higher than May 2011. May ice extent was 550,000 square kilometers (212,000 square miles) above the record low for the month, which happened in the year 2004.

[pottyprof]

Generally i am staying away from this thread as bftv is doing a very good job and the facts and figures speak for themselves.

Totally agree. He provides the detail without preaching and making the subject a turn off, which is much appreciated by all who read these threads, I'm sure. I certainly appreciate it.

[stewfox]

Yes the Arctic ice is holding up quite well at the present time and I will plumb

for a min of above 5 million this year.

I'm going for 5.4 million, although I dont see a competition this year no doubt as IJIS has been down.

[cooling climate]

Yep if the 3rd lowest extent on record and the lowest volume on record is holding up well he shows up the river without a paddle we are...

Generally i am staying away from this thread as bftv is doing a very good job and the facts and figures speak for themselves.

One word to sum up your post GULLIBLE.

[Gray-Wolf]

One word to sum up your post GULLIBLE.

Well I'm lost? In what way is the post gullible? Are you privvy to info not widely available to us all?

[BornFromTheVoid]

Some mild air with upper above 0C is now in place across much of the Chukchi, Beaufort, East Siberian Seas and the Pacific side of the Arctic basin. This warmth will intensify for the foreseeable future, with uppers of >5C becoming increasingly widespread around the Pacific end of the Arctic.

t0

t144

This is courtesy of a strong high pressure that looks set to remain in the area. The HP will likely allow for clear skies, allowing heating of the ocean which is already appearing through holes in the ice cover where the thin first year ice which is holding the thicker blocks together melts out. These small areas of open ocean are likely to grow as the water heats up melting the ice from below, while the warm air melts from above.

t0..................................................................t144

Here's a link to yesterdays MODIS Arctic mosaic image, where you can see the small holes appearing in the ice towards the top left of the image.

http://rapidfire.sci...12158.terra.4km

[Gray-Wolf]

http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl1_143.A2012158222000-2012158222500.250m.jpg

A blow up of the area BFTV drew our attention to. The majority is 2nd and 3rd year ice that has been churned by the Beaufort Gyre over the past winter. As we know the larger the surface area in contact with air/water the faster it melts. Not a lot of hope for this area of ice as high summer approaches. The ICEBridge mission had this ice at less than 2m which will not survive an average melt season. Even 2 seasons ago this area still held multiyear that lasted throughout the summer, not any more.

[cooling climate]

The ncep monthly time series has updated to include May and it was the 2nd strongest positive dipole on record (since 1948), with 1990 being the only year stronger, and it was the 2nd strongest April-May combination with 1990 being the only stronger one.

I suppose a bit of perspective on that, is that at this time in 1990, the sea ice area (for June 2nd coming off the back of the strongest May dipole on record) was only 200,000km2 lower than this year which is quite impressive and by far the lowest on record at the time. It wasn't until 2006 that a lower ice area was recorded for that date. Still, plenty of other factors at play so the dipole can't take all the blame!

The mean low was significantly deeper in 1990, causing a much stronger pressure gradient than in 2012.

I kept the scales here the same to show the differences between the 2 Mays

1990 & 2012

One of the reasons there is much more ice in the bering sea and Alaska this spring

is because of the lack of the positive dipole. Dear oh dear.

[BornFromTheVoid]

One of the reasons there is much more ice in the bering sea and Alaska this spring

is because of the lack of the positive dipole. Dear oh dear.

Yes, there was a negative dipole during the winter, so instead of the ice being pushed towards Fram Strait, the wind was encouraging more sea ice flow towards the Bering strait, pushing the cold Arctic air and sea ice into the Bering sea, bringing below average air temperatures and record high ice extent.

The opposite was occurring in the Kara and Barents sea's, which were having record low extents and high temperatures due to more southerly winds, pushing the sea ice northward and bringing milder air.

Since April the dipole has changed to a positive phase though, so the pattern has reversed somewhat.

Tis fairly straight forward.

Edited June 7, 2012 by BornFromTheVoid

[cooling climate]

Yes, there was a negative dipole during the winter, so instead of the ice being pushed towards Fram Strait, the wind was encouraging more sea ice flow towards the Bering strait, pushing the cold Arctic air and sea ice into the Bering sea, bringing below average air temperatures and record high ice extent.

The opposite was occurring in the Kara and Barents sea's, which were having record low extents and high temperatures due to more southerly winds, pushing the sea ice northward and bringing milder air.

Since April the dipole has changed to a positive phase though, so the pattern has reversed somewhat.

Tis fairly straight forward.

This is taken from the latest NSIDC update for May.

Figure 4. This map of sea level pressure anomalies for May 2012 shows that low pressure continued to dominate off of southern Alaska, resulting in northerly winds in the Bering Sea.

Credit: NSIDC courtesy NOAA/ESRL PSD

High Resolution Image

A persistent pattern of extensive ice in the Bering Sea

Continuing the pattern of the past six months, ice cover remained unusually extensive in the Bering Sea. Normally by the end of May, the Bering is largely ice-free, but this year, 350,000 square kilometers (135,000 square miles) of ice remained. As was also the case for February through April, May 2012 had the highest average Bering Sea ice extent for the month in the satellite record.

The higher than normal extent and late spring break up of the ice cover in the Bering Sea are mainly due to unusually low air temperatures and persistent winds from the north, related to a region of low atmospheric pressure centered over Kodiak, Alaska. As these cold winds slowed ice melt, they also pushed the ice edge to the south. The heavy ice in the region may delay the start of Shell Alaska’s Arctic drilling this summer, which will be the first exploratory drilling in the Arctic Ocean in 20 years.

With the overall springtime warming of the Arctic, the ice has nevertheless started to break up and large areas of open water are now present in the northern part of the Bering Sea.

Tis straight forward really.

Edited June 8, 2012 by cooling climate

[Gray-Wolf]

But why have we seen such interest in late formation , F.Y. ice living outside the basin?

The weather patterns driven by Arctic ice loss are developed by the sea areas, "inside the basin", that used to hold ice ,year round, and shield the ocean below from warming? The only interest I can see is to guide the way the atmosphere will respond to even larger areas of open water in the basin (as in the melt season ongoing?) as the warmed ocean loses heat in late Autumn lessening the temp gradient from Arctic into temp. regions.

To me we may well have seen the worst with only partial ice melt leaving areas that still develop winter cold which was then exported south. With most of the basin bereft of ice where would this 'winter cold' develop? In past ice free periods across the pole we have had vegetation at 80n that need temps of 50f min meaning that ocean warmth kept temps above the min throughout the winter months. To me it seems reasonable that temp regions min temperature will be regulated by the temperate region and not by 'Arctic plunges' in years to come. With no Arctic moderation northern hemisphere temp's will increase having only local air masses and tropical air masses driving the weather.

To me this will cause a large acceleration in global temps even with GHG's rising at the rates we see now as winter temps across the northern hemisphere 'mild out' in the absence of Arctic modification?

[BornFromTheVoid]

This is taken from the latest NSIDC update for May.

Figure 4. This map of sea level pressure anomalies for May 2012 shows that low pressure continued to dominate off of southern Alaska, resulting in northerly winds in the Bering Sea.

Credit: NSIDC courtesy NOAA/ESRL PSD

High Resolution Image

A persistent pattern of extensive ice in the Bering Sea

Continuing the pattern of the past six months, ice cover remained unusually extensive in the Bering Sea. Normally by the end of May, the Bering is largely ice-free, but this year, 350,000 square kilometers (135,000 square miles) of ice remained. As was also the case for February through April, May 2012 had the highest average Bering Sea ice extent for the month in the satellite record.

The higher than normal extent and late spring break up of the ice cover in the Bering Sea are mainly due to unusually low air temperatures and persistent winds from the north, related to a region of low atmospheric pressure centered over Kodiak, Alaska. As these cold winds slowed ice melt, they also pushed the ice edge to the south. The heavy ice in the region may delay the start of Shell Alaska’s Arctic drilling this summer, which will be the first exploratory drilling in the Arctic Ocean in 20 years.

With the overall springtime warming of the Arctic, the ice has nevertheless started to break up and large areas of open water are now present in the northern part of the Bering Sea.

Tis straight forward really.

Look at the pressure pattern CC, it is a clear +ve dipole.

If you're having difficulty understanding, here is the pressure pattern from November to the end of March with some annotations.

The temperature anomaly backs this up

As does the wind vector anomaly. Note the added northerly winds through the Bering Strait and anomalous southerlies in the Barents/Kara sea.

And because it is a dipole "anomaly", here clearly shows the negative anomaly pattern.

All of the above, to me at least, clearly shows why the sea ice anomalies into spring were the way they were.

Here is the pattern since April first, where you will see that it has been largely reversed.

See we have a classical +ve dipole pattern now, with low pressure to the Eurasian side and high pressure to the Canadian side.

The wind vector chart shows the extra wind forcing through the Fram strait, which is why the dipole drives extra sea ice export.

Here is the anomaly

Low pressure is being maintained to the south of Alaska, which is causing north easterly winds in the Bering sea. As the Arctic, and more specifically Alaska has been warming up, the ice in the Bering sea has been blown south and replaced with open water as it's not cold enough to refreeze and temperatures have returned close to average. You can see that on any ice concentration/area/extent or visual satellite image. Here's the temperature anomaly chart anyway, showing temps close to average since April over the Bering sea, a reduction in the positive anomalies over the Barents and Kara (still +ve due to the open water) -ve anomalies in the Greenland and North Sea, due to the strong northerlies here.

SSTs are very low around the Bering sea due to the northerly winds all winter and spring and because of the -ve PDO, so despite the ice being blown southward, and combined with the fact that there was an extra 400,000km2 of ice there, it's taking longer than normal to melt out (current anomaly is about +90,000km2).

Hope that helps CC. Any other questions, then feel free to ask and I'll do my best. On summer hols now so for the most part I have plenty of time.

[cooling climate]

Look at the pressure pattern CC, it is a clear +ve dipole.

If you're having difficulty understanding, here is the pressure pattern from November to the end of March with some annotations.

The temperature anomaly backs this up

As does the wind vector anomaly. Note the added northerly winds through the Bering Strait and anomalous southerlies in the Barents/Kara sea.

And because it is a dipole "anomaly", here clearly shows the negative anomaly pattern.

All of the above, to me at least, clearly shows why the sea ice anomalies into spring were the way they were.

Here is the pattern since April first, where you will see that it has been largely reversed.

See we have a classical +ve dipole pattern now, with low pressure to the Eurasian side and high pressure to the Canadian side.

The wind vector chart shows the extra wind forcing through the Fram strait, which is why the dipole drives extra sea ice export.

Here is the anomaly

Low pressure is being maintained to the south of Alaska, which is causing north easterly winds in the Bering sea. As the Arctic, and more specifically Alaska has been warming up, the ice in the Bering sea has been blown south and replaced with open water as it's not cold enough to refreeze and temperatures have returned close to average. You can see that on any ice concentration/area/extent or visual satellite image. Here's the temperature anomaly chart anyway, showing temps close to average since April over the Bering sea, a reduction in the positive anomalies over the Barents and Kara (still +ve due to the open water) -ve anomalies in the Greenland and North Sea, due to the strong northerlies here.

SSTs are very low around the Bering sea due to the northerly winds all winter and spring and because of the -ve PDO, so despite the ice being blown southward, and combined with the fact that there was an extra 400,000km2 of ice there, it's taking longer than normal to melt out (current anomaly is about +90,000km2).

Hope that helps CC. Any other questions, then feel free to ask and I'll do my best. On summer hols now so for the most part I have plenty of time.

That will give you plenty of time to savy up on the subject then hopefully we will see no more

needless posts like yours. If you are still unable to grasp what a positive dipole etc is then

feel free to PM me. Although I feel we may have to break a few bricks before we get anywhere.

[BornFromTheVoid]

I've noticed on the MODIS mosaic, that as the warm conditions have built over the Beaufort sea across the the East Siberian sea over the last few days, that the sea ice in this area has started turning blue, much like in the Laptev sea.

Here's an animation of the last 3 days for that area.

Makes it seem more likely that it's down to refraction from surface melt of the ice perhaps? Maybe it's just because I've been paying extra attention this year, but I can't say I've noticed the blue ice as widespread in other years.

Though if anyone has any images showing widespread blue ice in previous year, I'd be interested in having a look and comparing the atmospheric conditions with now.

Edited June 9, 2012 by BornFromTheVoid

[Gray-Wolf]

http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent_L.png

Well the current 'weather' across the pole is really starting to take it's toll as the past couple of days of high losses show. Due to the nature of the pack this year and the low start point inside the basin itself I'd expect heavier in-situ losses than we saw last summer. Couple this with what BFTV has been drawing our attention to and I predict a record low come Sept?

It would also appear that , if you kept to the coastline, you could already traverse the NE Passage! I saw a report about the passage also predicting a record early opening as the ice, when they overflew and measured ,was only 50cm thick (in early May!). They highlighted that in 2010 only 10 oceangoing vessels made the trip , last year this rose to 33. With this report out, and interest obviously stoked, I'd expect even higher volumes of cargo vessels this year.

If we recall it was ship capt.s making this passage last Aug/Sept that alerted the Russian authorities to the 'Boiling Oceans' above the submerged permafrosts. With open water earlier in the season I'd also expect an uptick in methane outpourings and similar reports (and vid's this time??) once the cargo vessels start running the passage.

All in all I'd expect that this season will finally silence the Pseudo-Skeptics who insist there are no problems in the basin and what we have documented through the noughties is 'recoverable' by natural climatic variations.