Arctic Sea Ice Discussion 2015: The Melt Season

[BornFromTheVoid]

Slight increase in the ADS extent yesterday, not unheard of at this time of year. Since 2002, during the first week of September there have been daily increases on 10 different occasions.

[oldsnowywizard]

There will be pleanty of opinions out there for why we have ended up where we are..my thoughts are as follows...

For the past 2 winters more especially last one, we saw that for most of the period the cold air was forced out over the hudson area... hence the reason for the late melt out here.... it would stand to reason that this meant the ice ( fragile due to the past ) did not get the required super and constant cold needed to help continue the trend... we therefore have a reset and a major one ... not yet as bad in terms of extent as the worst year...although the ice is clearly in the worst state i have seen it... with el nino this winter it will be interesting to see how the cold behaves in the arctic... it usually would be warmer and drier over canada and perhaps colder over europe .. .. lets hope the cold stays over the arctic.

[BornFromTheVoid]

There will be pleanty of opinions out there for why we have ended up where we are..my thoughts are as follows...

For the past 2 winters more especially last one, we saw that for most of the period the cold air was forced out over the hudson area... hence the reason for the late melt out here.... it would stand to reason that this meant the ice ( fragile due to the past ) did not get the required super and constant cold needed to help continue the trend... we therefore have a reset and a major one ... not yet as bad in terms of extent as the worst year...although the ice is clearly in the worst state i have seen it... with el nino this winter it will be interesting to see how the cold behaves in the arctic... it usually would be warmer and drier over canada and perhaps colder over europe .. .. lets hope the cold stays over the arctic.

 

It's been pointed out previously that last winter was significantly colder than recent averages, and the beginning of the melt season was back at 90s temperatures. To me, this season just highlights how fragile the pack is in general. Despite the relatively cool conditions, just one warm month (July) was enough to knock us back into the lowest  few years on record.

[Midlands Ice Age]

It's been pointed out previously that last winter was significantly colder than recent averages, and the beginning of the melt season was back at 90s temperatures. To me, this season just highlights how fragile the pack is in general. Despite the relatively cool conditions, just one warm month (July) was enough to knock us back into the lowest  few years on record.

 

Two points on this BFTV

 

1)  The cold last winter was centered on the Polar region and North of the USA. Here the ice is still 2 - 5 meters thick in most places in and around this area.The ice here is still much better than it has been for 5 years at least.

 

Also it is why ice still remains in the extreme north of the Hudson bay area as indicated by OSW above and why measurements of the volume of ice are not reducing quickly, whilst extent and area are..

 

2) The eastern Arctic area in general was mild last winter and it is here that the large Arctic extent and area losses have occurred.

 

If we do not get a cold winter this year over the eastern Arctic then we could well be facing an interesting and worrying future for the Arctic.

 

I have seen charts posted by Nouska which show that the expected El Nino based pattern could well induce major high level blocking in northern Scandinavia and Northern Russia  - so all is not lost (maybe).

 

Keep smiling and positive.

 

:D

 

MIA

[Gray-Wolf]

An Singularity's quote from Jen Francis on the state of the ice just reinforces, in my mind, that when we think of 'older ice' we should no longer think 'strong/resilient but old carcasses filled with FY ice ?

 

As for winter we have had another paper looking at the role ice loss plays in Polar Vortex going awol from the pole and the loss pattern this year would suggest that the U.S. will see another east coast snow fest? The Blob/Triple R seems to concur?

[stewfox]

It's been pointed out previously that last winter was significantly colder than recent averages, and the beginning of the melt season was back at 90s temperatures. To me, this season just highlights how fragile the pack is in general. Despite the relatively cool conditions, just one warm month (July) was enough to knock us back into the lowest  few years on record.

The high artic was again very mild last winter but had increase in volume. Let's not cherry pick. Over all volume and extent was very poor last winter.

[stewfox]

Slight increase in the ADS extent yesterday, not unheard of at this time of year. Since 2002, during the first week of September there have been daily increases on 10 different occasions.

 

Another very small increase yesterday, I wonder if we will have a early end to the melt season ? 

Edited September 5, 2015 by stewfox

[Geordiesnow]

It's been pointed out previously that last winter was significantly colder than recent averages, and the beginning of the melt season was back at 90s temperatures. To me, this season just highlights how fragile the pack is in general. Despite the relatively cool conditions, just one warm month (July) was enough to knock us back into the lowest  few years on record.

 

I suppose other factors could be considered in respect of that record breaking warmth that hit the Chuckchi sea in June which must of contributed to high SST's so bottom base melt would no doubt of intensified aswell as melt ponds rapidly forming. We also had some early 'heat' in the latter part of May hence the early opening of the ice in Beaufort but the way ice broke up and fell apart during the melt season in that region was quite something. 

 

I believe the start of the melt season was quite cold over the poles and Laptev(hence the slower opening of the ice here than in recent years) but it showed how thin the ice was in Laptev this year as once it finally got properly going, it did open rapidly and there was also rapid ice loss in the East Siberian Sea. 

 

One theory I got why Hudson may of been slower to melt was because the wind direction pushed the ice towards one end of the bay where as the other end was ice free coupled with the chilly conditions meant a slower melt here. 

 

I do believe if we had set ups like August 2014(Which unfortunately did melt/reduce the multi year ice that was there) then we could of been heading towards the lowest on record if not the lowest, so it could of been a lot worse but fortunately the weather patterns did change albeit bottom melt was occurring so melting was still above average. 

[Midlands Ice Age]

I suppose other factors could be considered in respect of that record breaking warmth that hit the Chuckchi sea in June which must of contributed to high SST's so bottom base melt would no doubt of intensified aswell as melt ponds rapidly forming. We also had some early 'heat' in the latter part of May hence the early opening of the ice in Beaufort but the way ice broke up and fell apart during the melt season in that region was quite something. 

 

I believe the start of the melt season was quite cold over the poles and Laptev(hence the slower opening of the ice here than in recent years) but it showed how thin the ice was in Laptev this year as once it finally got properly going, it did open rapidly and there was also rapid ice loss in the East Siberian Sea. 

 

One theory I got why Hudson may of been slower to melt was because the wind direction pushed the ice towards one end of the bay where as the other end was ice free coupled with the chilly conditions meant a slower melt here. 

 

I do believe if we had set ups like August 2014(Which unfortunately did melt/reduce the multi year ice that was there) then we could of been heading towards the lowest on record if not the lowest, so it could of been a lot worse but fortunately the weather patterns did change albeit bottom melt was occurring so melting was still above average. 

 

Geordiesnow..

 

I felt you had put a very good summary forward to describe  the melt season.

 

However the last paragraph gives it all away.

 

It is your belief that, etc ..... but  It didn't occur, so it is a 'could have been'. If my auntie was my uncle... comes to mind.

 

and

 

'bottom melt was still occurring and so melt continued at above average rates' - whilst true, but why  in that case why was area and extent so badly hit and not the total volume?

According to your parting shot it should have been the volume that was hit hardest. Surely the season was characterized by the expected ice melt of the areas so badly affected by poor conditions at the end of the last winter season. 90% of your post describes that situation very well.

 

The last paragraph is speculation.

[BornFromTheVoid]

Two points on this BFTV

 

1)  The cold last winter was centered on the Polar region and North of the USA. Here the ice is still 2 - 5 meters thick in most places in and around this area.The ice here is still much better than it has been for 5 years at least.

 

Also it is why ice still remains in the extreme north of the Hudson bay area as indicated by OSW above and why measurements of the volume of ice are not reducing quickly, whilst extent and area are..

 

2) The eastern Arctic area in general was mild last winter and it is here that the large Arctic extent and area losses have occurred.

 

If we do not get a cold winter this year over the eastern Arctic then we could well be facing an interesting and worrying future for the Arctic.

 

I have seen charts posted by Nouska which show that the expected El Nino based pattern could well induce major high level blocking in northern Scandinavia and Northern Russia  - so all is not lost (maybe).

 

Keep smiling and positive.

 

:D

 

MIA

 

Centered on the polar region? You've kinda lost me. The entire Arctic is a polar region!? As for north of the USA... do you mean Canada?

 

Ice occasionally remains just at the northern tip of Hudson Bay, from the CT data, the extra ice there just means that Hudson Bay coverage is about average. It means very little in the context of the whole Arctic though, especially when some area are over a million km2 below average.

 

Large extent and area loss have occurred in every part of the Arctic, not just the east. Look at the CT regional data http://arctic.atmos.uiuc.edu/cryosphere/

 

C'mon now, we all know how reliable long range weather forecasts are. I certainly won't be relying on any forecasts, but as it is, we don't know how next year will go.

 

 

The high artic was again very mild last winter but had increase in volume. Let's not cherry pick. Over all volume and extent was very poor last winter.

 

Very mild, but less mild than recent years. I specifically said colder than recent averages. Your false accusations are getting a bit tiring, Stew.

 

 

That's last winter being 0.97C colder than the average of the last 10 years.

[stewfox]

Another 5k rise yesterday. Some 27k above Wednesdays minimum

 

Far too early to call yet but still good to see.

 

https://ads.nipr.ac.jp/vishop/vishop-extent.html?N

[stewfox]

 

Very mild, but less mild than recent years. I specifically said colder than recent averages. Your false accusations are getting a bit tiring, Stew.

 

 

That's last winter being 0.97C colder than the average of the last 10 years.

 

 

You said  """"last winter was significantly colder than recent average"" we can see it was average compared to recent years and milder then pre 2000 from your own graph

 

We also know temps 80N were way above average last winter as they have been for the last decade.

 

Rather they say the arctic was significantly colder then average last winter it needs to be put in perspective re where when and amount of absolute variation.

Edited September 6, 2015 by stewfox

[BornFromTheVoid]

I suppose other factors could be considered in respect of that record breaking warmth that hit the Chuckchi sea in June which must of contributed to high SST's so bottom base melt would no doubt of intensified aswell as melt ponds rapidly forming. We also had some early 'heat' in the latter part of May hence the early opening of the ice in Beaufort but the way ice broke up and fell apart during the melt season in that region was quite something. 

 

I believe the start of the melt season was quite cold over the poles and Laptev(hence the slower opening of the ice here than in recent years) but it showed how thin the ice was in Laptev this year as once it finally got properly going, it did open rapidly and there was also rapid ice loss in the East Siberian Sea. 

 

One theory I got why Hudson may of been slower to melt was because the wind direction pushed the ice towards one end of the bay where as the other end was ice free coupled with the chilly conditions meant a slower melt here. 

 

I do believe if we had set ups like August 2014(Which unfortunately did melt/reduce the multi year ice that was there) then we could of been heading towards the lowest on record if not the lowest, so it could of been a lot worse but fortunately the weather patterns did change albeit bottom melt was occurring so melting was still above average. 

 

Agreed, looking regionally, there were some hot spots at times like in Chukchi, but there were a few cold spots too.

 

The melt has been a bit slower in Hudson Bay this year, but only to the point of being about average. I think there are much more interesting things going on then an average melt rate in Hudson. But I can understand why some want to keep attention focused on the one region that improved over recent years (even if it still melts out almost entirely!).

 

North of 70N, this August has been the second coldest in the last 10 years. 

 

Geordiesnow..

 

I felt you had put a very good summary forward to describe  the melt season.

 

However the last paragraph gives it all away.

 

It is your belief that, etc ..... but  It didn't occur, so it is a 'could have been'. If my auntie was my uncle... comes to mind.

 

and

 

'bottom melt was still occurring and so melt continued at above average rates' - whilst true, but why  in that case why was area and extent so badly hit and not the total volume?

According to your parting shot it should have been the volume that was hit hardest. Surely the season was characterized by the expected ice melt of the areas so badly affected by poor conditions at the end of the last winter season. 90% of your post describes that situation very well.

 

The last paragraph is speculation.

 

Arctic air temperatures begin dropping away during August and melt becomes dominated by the ocean. That isn't speculation, rather it's the reality. So the heat built up in the ocean partially determines the melt potential during August. You then rely on winds to push the warmer waters into the ice.

This year, while we still lost a decent amount of volume during August, we eliminated most of the thick ice from the Pacific side of the Arctic during July, so there wasn't much thick ice left for the warm SSTs to eat away at. This meant that the fragmented bits of ice around Beaufort and Chuckchi faded, causing drops in area and extent without equivalently big drops in volume.

 

 

 

So from the above map, you can see that the regions with warm SSTs aren't where any thick ice is left. And without dipole conditions to push the ice and water into the central pack, the warm SSTs can't do a whole lot.

[BornFromTheVoid]

You said  """"last winter was significantly colder than recent average"" we can see it was average compared to recent years and milder then pre 2000 from your own graph

 

We also know temps 80N were way above average last winter as they have been for the last decade.

 

Rather they say the arctic was significantly colder then average last winter it needs to be put in perspective re where when and amount of absolute variation.

 

I never once said they weren't milder than the long term. But we know that, because the Arctic is rapidly warming, much faster than the rest of the planet.

 

When it comes to recent averages, I calculated the average of the 2005-2014 winters (10 years, recent), -22.893C. I then subtracted that average form the 2015 winter temperature, -23.859C. Which gives an anomaly of -0.966C below the recent average. So no, that is categorically not average compared to recent years. It's the 4th coldest since 2000, and the 2nd coldest since 2005.

 

Here's a link to the data if you want http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=Air+Temperature&level=2000&lat1=70&lat2=90&lon1=0&lon2=360&iseas=1&mon1=11&mon2=1&iarea=1&typeout=1&Submit=Create+Timeseries

[knocker]

Change-Point analysis and N. Hemisphere sea ice extent.

 

https://tamino.wordpress.com/2015/09/06/change-point-fun/

[BornFromTheVoid]

NSIDC daily extent now just 45k off the 3rd lowest minimum on record, while the 5 day mean is 116k off.

 

CT area will be within 22k of the 2010 minimum by Thursday's update, and within 190k of the 2nd lowest minimum on record.

[BornFromTheVoid]

ADS extent is now 28k off the 3rd lowest minimum on record.

[BornFromTheVoid]

Below are the rankings for 925hPa air temperatures north of 72.5N, based on the ncep reanalysis for since 1948 (1 is mildest).

 

Year  .. May.June..July.Aug.MJJA

2007.... 22.....2......4.....3......3

2008.... 8......19....12....4......8

2009....19....40......9....17....17

2010.... 1.......6.....25....9......5

2011.... 7.......5......1.....2......1

2012.... 5.......4......6....10.....4

2013.... 30....38....15...34....30

2014.... 28....41....38...18....31

2015.... 27....11.....2....26....13

 

2015 comes out as the 13th mildest on record. (For anyone wondering where 2nd place overall is, it is 2005).

[BornFromTheVoid]

Daily NSIDC extent has now just 8k off the 2011 minimum in 3rd place and 194k off the 2007 minimum in 2nd place.

[Midlands Ice Age]

 

Below are the rankings for 925hPa air temperatures north of 72.5N, based on the ncep reanalysis for since 1948 (1 is mildest).

 

Year  .. May.June..July.Aug.MJJA

2007.... 22.....2......4.....3......3

2008.... 8......19....12....4......8

2009....19....40......9....17....17

2010.... 1.......6.....25....9......5

2011.... 7.......5......1.....2......1

2012.... 5.......4......6....10.....4

2013.... 30....38....15...34....30

2014.... 28....41....38...18....31

2015.... 27....11.....2....26....13

 

2015 comes out as the 13th mildest on record. (For anyone wondering where 2nd place overall is, it is 2005).

 

I have found a wifi hotspot tonight!!!

 

I  liked this post, BFTV because I found it really interesting that 2013 - 2014 were so cold in the Arctic and yet we had mildish winters. Whereas we had cold winters in 2009 2010 and 2011. So it seems as though Arctic outbreaks for us are not all 'good' for Arctic ice.

 

I think what will be really interesting is if this year we can 'squeeze' an anticyclone for Scandy and Siberia out of the El Nino and then see what happens to the ice then!

 

MIA

[stewfox]

 

I  liked this post, BFTV because I found it really interesting that 2013 - 2014 were so cold in the Arctic and yet we had mildish winters. Whereas we had cold winters in 2009 2010 and 2011. So it seems as though Arctic outbreaks for us are not all 'good' for Arctic ice.

 

I think what will be really interesting is if this year we can 'squeeze' an anticyclone for Scandy and Siberia out of the El Nino and then see what happens to the ice then!

 

MIA

 

 

 

Modeled temperature in 925 hPa (2000 ft a.s.l.) to make a rough estimate on the expected maximum temperature in 2m above the ground. However, this method does not apply to (winter) inversions.

 

You can see how mild it has been in the Arctic at 2m level. 2015 and 2011 (as have all recent years)

 

IJIS up 46,000 yesterday

 

https://ads.nipr.ac.jp/vishop/vishop-extent.html?N

Edited September 11, 2015 by stewfox

[BornFromTheVoid]

Modeled temperature in 925 hPa (2000 ft a.s.l.) to make a rough estimate on the expected maximum temperature in 2m above the ground. However, this method does not apply to (winter) inversions.

 

You can see how mild it has been in the Arctic at 2m level. 2015 and 2011 (as have all recent years)

 

IJIS up 46,000 yesterday

 

https://ads.nipr.ac.jp/vishop/vishop-extent.html?N

 

Your should really source your stuff when you copy and paste (especially when it's referring to weather models and not entirely related to Arctic weather). Also, there isn't always an inversion and 925hPa works much better for the summer months than surface temps.

 

It's been said time and time again, but once more, north of 80N is a poor representation of the Arctic, it's really a very small area. It's like using Wales to represent the Britain.

 

This image is better, and represents the whole Arctic ocean.

 

 

 

http://cires1.colorado.edu/~aslater/ARCTIC_TAIR/

[Midlands Ice Age]

Your should really source your stuff when you copy and paste (especially when it's referring to weather models and not entirely related to Arctic weather). Also, there isn't always an inversion and 925hPa works much better for the summer months than surface temps.

 

It's been said time and time again, but once more, north of 80N is a poor representation of the Arctic, it's really a very small area. It's like using Wales to represent the Britain.

 

This image is better, and represents the whole Arctic ocean.

 

 

 

http://cires1.colorado.edu/~aslater/ARCTIC_TAIR/

 

BFTV...

 

Not sure if there is too much between the two representations.....

 

Essentially they both depict long periods of time above the median over the 81-10 figure.

 

Your graphs do not show anything out of the normal 2 std deviations (apart from the exceptional warmth in July -  Aug period), and hence do not look exceptional, but the temp did spend a lot of the time above the median , whereas Stu's show just above the average figures.

 

Could I also say, that these  representations do show the period in May which was good for the ice as a colder period (though not exceptionally so).. Apart from that there  were only short periods of below normal,exactly as Stu had suggested.

 

In fact, it looks as though 2011 spend slightly longer periods during the whole freeze season below the median.

 

So for these two years, I think there is little difference...

 

MIA

[stewfox]

BFTV...

 

Not sure if there is too much between the two representations.....

 

 

In fact, it looks as though 2011 spend slightly longer periods during the whole freeze season below the median.

 

So for these two years, I think there is little difference...

 

MIA

 

In need and 4 of the first 5 months of this year were above average and if you were to show all years from 2000 you would largely see the red line above the median of 1980s 1990s. I dont see why there is a debate re Arctic getting colder it isn't. Also surface temps melt the ice not that at 2000ft hence when it hits 15c at 925pha in July it can still be 3/4c at 2m. Anyway the comment was it was much colder then average last year in the arctic and clearly from both graphs we can see it wasnt.

Edited September 11, 2015 by stewfox

[stewfox]

Another increase yesterday (extent)

 

Could the 8th sept be the min , if it is will be a early start to the refreeze.

 

https://ads.nipr.ac.jp/vishop/vishop-extent.html?N

Edited September 12, 2015 by stewfox