Arctic sea ice and jet stream changes

It's the most interesting and actual of all potential risks tied to Arctic sea ice loss and could turn out to be one of the surest signs of changing weather patterns. Which explains the growth in interest and research.

One of the latest scientific papers on this subject, Influence of Arctic sea ice on European summer precipitation, has been written by Dr. James Screen of the University of Exeter and published in Environmental Research Letters (via the Econnexus Blog).

The publication of the paper has been accompanied by a video, which has been put on YouTube by Peter Sinclair from the ClimateCrocks Blog, which makes it easier to embed (thank you, Peter):

 

Comments

[JackTaylor]

Susan Anderson | November 07, 2013 at 19:58 "I dropped in to go totally off topic, with apologies: typhoon Haiyan is bearing down on the Philippines"

Not OT - imo We need to keep it in perspective there is more to the story than Atlantic Basin Hurricanes

Any chance you may have seen something that implies cyclones - typhoons in the Pacific may be sucking heat out the oceans and preventing - delaying - reducing El Nino's ?

[Susan Anderson]

JT: I have put in a query to my "expert" and all I can say for now is that they vent heat towards the polar region and also to the troposphere which also ends up at the pole. Pacific is obviously a large ocean basin with a lot more excessive heat in it. They've had a barrage of supertyphoons in the last few weeks, it seemed a mite abnormal me so I started looking at it recently. I keep up with Wunderground and their comments are the place to go. Masters has done yet another post about this which has just made landfall near a city of over 200,000 people.

[Susan Anderson]

sorry, Wunderground link:

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2573

[wili]

Maters now notes that Haihan is the strongest cyclone in history to make landfall.

As predicted, though their total numbers may not be going up and may even decrease, when cyclones do get going in our super heated, super humid world, they can get to be very, very large.

The "storms of our grandchildren" seem to be making an early visit on the grandparents already.

[Kate]

Super Typhoon Haiyan dispersed an awful lot of heat very quickly. Typhoons/cyclones are the only very fast way of moving heat between ocean, land and atmosphere aren't they?

[MarkH]

Neven having a go at me for using the word 'we' is fair enough and I stopped posting as I was being a bore!

Since I have been told off again by others I just want to add a note that I was responding to several fairly broad and general posts that had used the word 'we' and referred to 'man' or 'humanity'. My 'we' referrred to the very first para of my post where i referred to humanity. I am not presumptious of other peoples opinions or theories I do however assume all posters belong to 'humanity' to which my posts referrred.

To Neven I apologise for boring him

[Neven]

No problem, Mark. I bore myself constantly.

[wili]

Kate: yes, I would think so.

Meanwhile, estimates are that Haiyan has killed 10,000 people just on the island of Leyte (if I read this correctly):

"On Leyte, regional police chief Elmer Soria said the provincial governor had told him there were about 10,000 deaths there, primarily from drowning and collapsed buildings."

http://world.time.com/2013/11/09/philippine-typhoon-death-toll-could-reach-10000/

[John Christensen]

Regarding Haiyan:

This cyclone is not nearly record strong, but unfortunately made landfall at peak strength (http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2573):

"The Japan Meteorological Agency estimated Haiyan's central pressure at 895 mb at 18 UTC (1 pm EST) November 7, 2013. This would make Haiyan the 12th strongest tropical cyclone on record globally, as far as lowest pressure goes."

It would appear reasonable to suggest that sinking dry air, which has significantly reduced Atlantic hurricane activity this year (http://www.climatecentral.org/news/what-happened-to-the-2013-atlantic-hurricane-season-16616) has not been the case in the western Pacific, or has even eased upward air movement east of the dry air masses of Africe, especially since SST in western Pacific is not out of the norm (http://ocean.dmi.dk/satellite/index.uk.php).

[John Christensen]

A severe low in North West Atlantic reaching 950-960mb pressure right now:

http://ocean.dmi.dk/arctic/weather/arcticweather_imagecontainer.php

[Blaine]

The conclusion of the Jennifer Francis paper that jet stream wiggles are extending farther northward seems to me to be likely correct, but the methodology is suspect. It's the slowing of meander progression which is the more robust conclusion from the paper. The ~5% reduction in progression speeds is rather small, but misses much of the effects of blocking, and persistent rainfall or drought. Unless it it large enough to make the jet stream wiggle disappear altogether, a persistent additive high pressure will just make low pressure troughs move through it quickly, doing nothing which appears in the data of the Francis paper.

Over warm land, there is a major positive feedback associated with humidity. If there is water available at the surface, this will lead to high humidity, upward transfer of heat by condensation, a lower surface pressure, and net surface convergence causing higher humidity and more rain. This feedback has always existed, but since it depends on absolute water vapor concentration, it is much stronger when it is warmer, and generally increases with global warming. The opposite positive effect occurs as well, resulting in persistent drought, including fires in northern regions where the lack of previous fires indicates that this drying has not happened before in a very long time. In mid-temperate and farther poleward climates, the effect is small during the winter and the effect normally does not carry over much from year to year.

Greenland blocking and the associated NAO- state as well wetness western Europe in are closely associated with deep convection in the Labrador Sea, and have seen a sharp shift in the past decade or two. This shift is not likely to reverse soon, but it should reverse eventually, although only partially because global warming has a somewhat similar effect.

This year saw an extreme negative arctic dipole associated with high pressure blocking in western Siberia. The extreme northern Atlantic is warmer and saltier than ever, so this high pressure led to humidity blown over the central Arctic Ocean, and a surprising amount of low pressure and storminess there. This is a significant negative feedback which we have not seen before to anything near this extent, but it is more likely than not that next year will not have the mostly random high pressure blocking at the same place to cause it again.