Sea Surface Temperature And Sea Ice Trends

[WhiteFox]

It is just to the west of Ireland, it was bigger a few days ago.

Fair enough. Seems to have totally vanished now. The nearest cold pool is to the west of Spain or way north of Scotland.

[BLAST FROM THE PAST]

Interestingly, (related to our other discussion, Blast), the press release that these reports are based on (from the University of Texas at Austin - click on 'news'), suggests as one idea that this could be the consequence of a weakening of the THC, leading to less cold water coming down the shallow Greenland Ice Shelf.

There's an interesting paper on this, from March 2006, on http://www.realclimate.org/index.php?p=267

(It's also worthwhile to read the blogs at the bottom)

The paper points out that three different recent papers have come up with three different estimates of ice mass balance from the same data; the latest is an update of these.

P

Basically the plot thickens IMO. Thanks P that was a very good read.

BFTP

[parmenides3]

Basically the plot thickens IMO. Thanks P that was a very good read.

BFTP

Thanks. The trouble is, the more I look into this, the more uncertain my opinions become. When I've finished the housework, I'm going to sit down and try to do a bit of calculating. Don't hold your breath.

P

[Stratos Ferric]

SF

Yes it was brought up yesterday by Parmenides3, I think specifically in the very recent years as in this century. Even though the interiro has been 'cold' with increased precip the coastal retreat has increased. Ocean warming?

BFTP

I only really follow the ice situation sporadically, and perhaps therefore a tad selectively, but the bits I've picked up this year is that extent, whilst a concern, is actually less of an issue than declining thickness. Until now it's not been easy to track the latter.

[Stratos Ferric]

Interestingly, (related to our other discussion, Blast), the press release that these reports are based on (from the University of Texas at Austin - click on 'news'), suggests as one idea that this could be the consequence of a weakening of the THC, leading to less cold water coming down the shallow Greenland Ice Shelf.

There's an interesting paper on this, from March 2006, on http://www.realclimate.org/index.php?p=267

(It's also worthwhile to read the blogs at the bottom)

The paper points out that three different recent papers have come up with three different estimates of ice mass balance from the same data; the latest is an update of these.

P

Agree, a good read. Amusing to read the various peer challenges at the foot (I assume this is the "BLOG" you refer to - though I don't think they're "blogs" really), and to see that, albeit at a slightly higher average level of science than we manage here on N-W, the thrust and counter thrust between those who believe something is amiss, and those who don't, is present here too. Some very good comments in there though.

[parmenides3]

I only really follow the ice situation sporadically, and perhaps therefore a tad selectively, but the bits I've picked up this year is that extent, whilst a concern, is actually less of an issue than declining thickness. Until now it's not been easy to track the latter.

Hi, SF. Both extent and cover are terms used to describe how much of the Arctic is covered by sea-ice. Until 1979 and satellites, the only measure possible was extent. Because of this, it is still measured in this way, so that comparisons can be made fairly with historic data. Current sea-ice extent is less than 6.5M km2, the lowest it has ever been in the record. This is the fifth year in a row that the extent has broken the previous record. It definitely is a concern!

The term cover is used to refer to the more accurate measurement of the ice, which subtracts the 'pools' within the ice from the extent; it is, of course, more accurate. The satellite record from 1979 shows a rapid decline in levels, particularly during the Summer. Because it is believed to be particularly sensitive to climate warming, sea-ice is a good indicator of trends. Because it acts as a heat sink and a feedback mechanism, as well as a contributor to sea level, the state of sea ice is important to all of us, as our climate is increasingly likely to be affected by changes at the Pole.

Thickness is a bit trickier. About the only way to measure it is from below, in a nuclear sub. (A new research programme is using remote, torpedo-like drones). When this was done in the late 90's, Rothrock et. al. concluded that thickness had reduced on average by 30% since the 1960's. Because it is so hard to measure, programmes like GRACE have been set up to calculate the mass balance of the ice sheets from space.

However it is measured, there is no doubt that there is a lot less sea-ice than there used to be and, for the time being, there is no indication of the declining trend ending. This is one of the reasons why the current conditions are of direct relevance to NW; what happens there has a big impact, directly and indirectly, on what happens her and elsewhere in the world.

Hope this helps to stimulate more interest. For a daily 'snapshot', search for 'Cryosphere Today'; it is the basis of much of our discussions on this thread.

P

[Damien]

SF

Yes it was brought up yesterday by Parmenides3, I think specifically in the very recent years as in this century. Even though the interiro has been 'cold' with increased precip the coastal retreat has increased. Ocean warming?

Yes, that's what Mr. Felix said when he was interviewed on talkSPORT. BBC Horizon - I think it was the "Global Dimming" episode - also confirmed this to be a fact. :lol:

And Stratus, what do you think of carinthian's "Barents Sea" theory? I don't know what to think about; but it sounds similar (albeit contextually different) to the polar cell theory that let Metcheck down in 2004/05.

[summer blizzard]

There have been some interesting sea surface temperature anomoly developments over the past few days, the warm anomoly off Newfoundland has moved east, and as a result of a positive PNA pattern, cold anomolies are building behind the warm anomoly, this signifies the development of negative NAO, while the warm anomoly remains in the Baltic, cold anomolies have also emerged as far south as the north coast of Scotland, this indicates a more southerly tracking Jet Stream.

[summer blizzard]

There have been some more interesting developments in the past week, these are:

1) Huge warm anomolies to the west of Siberia, this has a negative correlation with the West Pacific Occilation, therefore, we should expect a very negative West Pacific Occilation during September

2) There is a fairly even split between warm and cold anomolies in the Pacific Occilation, this indicates a neutral PDO, most likely slightly positive

3) Cold anomolies in the eastern Pacific indicate a negative East Pacific Occilation

4) Cold anomolies either side of the USA indicate a neutral PNA, indicating a large thermal gradiant over the USA

5) Cold, Warm, cold tripole indicates a negative NAO, extra-tropical banding also indicates a very negative NAO

Based on these factors, i would call for the CET to be more than 1C below average by mid September if AO is negative, if the AO is positive, we may manage a two day heatwave bringing the CET upto average.

[BLAST FROM THE PAST]

There have been some more interesting developments in the past week, these are:

1) Huge warm anomolies to the west of Siberia, this has a negative correlation with the West Pacific Occilation, therefore, we should expect a very negative West Pacific Occilation during September

2) There is a fairly even split between warm and cold anomolies in the Pacific Occilation, this indicates a neutral PDO, most likely slightly positive

3) Cold anomolies in the eastern Pacific indicate a negative East Pacific Occilation

4) Cold anomolies either side of the USA indicate a neutral PNA, indicating a large thermal gradiant over the USA

5) Cold, Warm, cold tripole indicates a negative NAO, extra-tropical banding also indicates a very negative NAO

Based on these factors, i would call for the CET to be more than 1C below average by mid September if AO is negative, if the AO is positive, we may manage a two day heatwave bringing the CET upto average.

Carrying on from another thread that Steve Murr pointed out re very southerly jet this late August, are we to see a continued pattern then. With low CET anticipated that seems likely then,

BFTP

[summer blizzard]

If the AO plays ball, then sea surface temperature anomolies do favour a southerly tracking Jet Stream, if the AO were to go positive, i can only see average at best, this is because unlike in June and July when we had an Azores Low, cold sea surface temperature anomolies are situated in the western Mediterranian Sea, therefore the downstream ridge would be situated over central and eastern Europe, not western Europe.

[summer blizzard]

Here is the latest chart...

[Glacier Point]

Indeed, a stunner which reflects the recent trend as we enter the crucial period when residual SSTAs are most likely to inlfuence the long term winter patterns...

Highlights for me:

1) largely inactive Pacific with cold anomalies in the eastern N-Pac likely to induce a neutral East Pacific Oscillation (EPO);

2) generally -ve North Atlantic Oscillation signal arising from the stonking warm anomaly mid-Atlantic;

3) continued cold anomalies in the Azores - likely to drive the sub-topical and polar jets southwards and displace the high pressure core NW towards the central north Atlantic warm anomaly zone - resulting in mid-Atoantic mean ridge.

If, repeat if, the current trend for -ve Arctic Oscillation continues into December, this would auger extremely well for western Europe to be staring down the barrel of a cold Winter. On the other hand, should polar region cool or another stratospheric cooling event take place, a +ve AO will likley trend the Scandinavian ridge and southerlies rather than northerlies result.

Continued strong anomalies to the meridional wind pattern looks very probable in either scenario though.

GP

[BLAST FROM THE PAST]

Continued strong anomalies to the meridional wind pattern looks very probable in either scenario though.

GP

[kold weather]

That is one hell of a warm SSTA in the Mid-Atlantic there, 4C above average and that is probably the main reason for Autumn getting going earlier then recent years because that must have really boosted the temp gradiant along with the eastern artic cool pool that was present as well.

[parmenides3]

As far as Polar cooling, Wz. is consistently showing rapid temp. drops holding as far out as the forecasts go, though there is still a noticeable difference between Greenland & the Pole and the lat. 70s. A 'sausage' is evident on the 500 & 850 charts, stretching from Hudson Bay across the Pole to the Barents. Closer to home, the chart looks like this (if I can get it to post).

As said elsewhere, sea-ice level is still falling overall, including in the Greenland Sea. Some cold pooling to the North of Norway & especially in the Barents, has been persistent for a couple of weeks, now.

Overall, I'd have though that the very warm N. Atlantic suggests that the MetO long-term for Winter is a reasonable assumption.

:blush: P

Sorry, can't get the chart to load.

[beng]

My concern regarding the North Atlantic warm anomoly off Newfoundland is that it may not quite be far north enough - ie it doesn't quite stretch to the South and West of Greenland - at least according to unisys. This I would think could lead to enhanced cyclogenisis just south of Greenland - rather than to the West - which is where we'd like it for the purposes of the neg NAO. Appreciate some feedback on this point as I could be wrong etc.

The following chart looks a bit more favourable to me though

http://www.osdpd.noaa.gov/PSB/EPS/SST/climo.html

[shuggee]

As I understand these things (don't giggle) warm sea temp anomalies off Greenland can be the death knell for a cold UK winter - encouraging cyclogensis where the warm sea meets the cold land and resulting in a very positive NAO - with semi-permanent low pressure ensuring an endless stream of SW'ly winds bringing depressions off the Atlantic across the UK.

[summer blizzard]

That is one hell of a warm SSTA in the Mid-Atlantic there, 4C above average and that is probably the main reason for Autumn getting going earlier then recent years because that must have really boosted the temp gradiant along with the eastern artic cool pool that was present as well.

I believe this explains the recent northerly type weather, because the warm west/cold east creates a north to south thermal gradiant, as the current sea surface temperature anomolies go, a negative NAO is favoured in early September, i we can get stronger extra-tropical banding, then we could see quite a strong negative NAO.

[Weather-history]

.

http://www.wetterzentrale.de/archive/ra/20...00120030201.gif

Not the greatest example shuggee, it did snow a couple days after that chart

From the winter of 1989-90

Edited August 23, 2006 by Mr_Data

[shuggee]

Mr D

I was being lazy. Unfortunately I cannot figure out the codes on the Unisys site to find the corresponding SST Anomaly charts to illustrate the point further. Can anyone help?

[Glacier Point]

As I understand these things (don't giggle) warm sea temp anomalies off Greenland can be the death knell for a cold UK winter - encouraging cyclogensis where the warm sea meets the cold land and resulting in a very positive NAO - with semi-permanent low pressure ensuring an endless stream of SW'ly winds bringing depressions off the Atlantic across the UK.

a winter of strong jet flow running from the SW USA across the Atlantic to the UK:

and a complete lack of blocking to the north. Could happen again, but I think the established meridional pattern would make weaker jet flow a more probable outcome.

Edited August 23, 2006 by Glacier Point

[summer blizzard]

This is the chart which brought the pattern you observed in 2003, as you can see, sea surface temperature anomolies indicate a strong Atlantic Jet Stream, the only saving grace being that the anomolies also indicate a Scandinavian Trough and the possibility of the Grenland High building.

[shuggee]

What a great illustration - thanks to Mr D and SBz

[summer blizzard]

There are no major changes today, however i am going to have a go at pinpointing an individual event, if i am right, the Jet Streams will phase over the eastern USA around the 15th, this could lead to a major storm in that region which after traveling over the most anomolous waters in the Atlantic, could produce a major storm for us around the 15th to 20th September.