Arctic Sea Ice : Forum

AGW in general => Consequences => Topic started by: BornFromTheVoid on February 26, 2013, 11:24:29 AM

Title: Arctic Amplification and Extreme Weather
Post by: BornFromTheVoid on February 26, 2013, 11:24:29 AM
Yet more evidence of the link

Quote
Weather Extremes Provoked by Trapping of Giant Waves in the Atmosphere

The world has suffered from severe regional weather extremes in recent years, such as the heat wave in the United States in 2011 or the one in Russia 2010 coinciding with the unprecedented Pakistan flood. Behind these devastating individual events there is a common physical cause, propose scientists of the Potsdam Institute for Climate Impact Research (PIK). The study will be published this week in the Proceedings of the National Academy of Sciences and suggests that man-made climate change repeatedly disturbs the patterns of atmospheric flow around the globe's Northern hemisphere through a subtle resonance mechanism...

...Anomalous surface temperatures are disturbing the air flows
Climate change caused by greenhouse-gas emissions from fossil-fuel burning does not mean uniform global warming -- in the Arctic, the relative increase of temperatures, amplified by the loss of snow and ice, is higher than on average. This in turn reduces the temperature difference between the Arctic and, for example, Europe, yet temperature differences are a main driver of air flow. Additionally, continents generally warm and cool more readily than the oceans. "These two factors are crucial for the mechanism we detected," says Petoukhov. "They result in an unnatural pattern of the mid-latitude air flow, so that for extended periods the slow synoptic waves get trapped."

http://www.sciencedaily.com/releases/2013/02/130225153128.htm?utm_source=dlvr.it&utm_medium=twitter (http://www.sciencedaily.com/releases/2013/02/130225153128.htm?utm_source=dlvr.it&utm_medium=twitter)
Title: Re: Arctic Amplification and Extreme Weather
Post by: crandles on February 26, 2013, 12:04:33 PM
Quasi-resonant amplification of planetary waves and recent Northern Hemisphere weather extremes.
Petoukhov, V., Rahmstorf, S., Petri, S., Schellnhuber, H. J.

Jennifer Francis not involved in this. Does that mean she has lost race to publish first or has she already published?

Quote
The authors of the study developed equations that describe the wave motions in the extra-tropical atmosphere and show under what conditions those waves can grind to a halt and get amplified.

That does sound more sophisticated than the fairly simple approach Dr Francis talked about in the video.
Title: Re: Arctic Amplification and Extreme Weather
Post by: ivica on February 26, 2013, 01:00:08 PM
Let me add link to quite recent example of extreme weather:
http://www.srh.noaa.gov/ama/?n=feb25blizzard (http://www.srh.noaa.gov/ama/?n=feb25blizzard)

Amarillo, TX, but w/o those 2 trees who could say that it is not from inside Arctic Circle:
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.srh.noaa.gov%2Fimages%2Fama%2Fevents%2F2013%2Ffeb25blizzard%2Fnws1.JPG&hash=fed443fa8919b1b21733eb2da426078d)
Title: Re: Arctic Amplification and Extreme Weather
Post by: Gray-Wolf on February 26, 2013, 06:44:26 PM
In the past the extension of Arctic cold was not too much of an issue but today I have to wonder what replaced the cold where it came from?

Every time I see a 'heartland-esque' response to cold weather plunges I always look to see where the Warm Air Advection went.
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on February 26, 2013, 10:47:36 PM
Jennifer Francis not involved in this. Does that mean she has lost race to publish first or has she already published?

I've not seen the work she described in the recent video published.  Anyone??

Quote
The authors of the study developed equations that describe the wave motions in the extra-tropical atmosphere and show under what conditions those waves can grind to a halt and get amplified.

That does sound more sophisticated than the fairly simple approach Dr Francis talked about in the video.

It does sound like a different approach, but coming to much the same conclusion as, Jennifer A. Francis, Stephen J. Vavrus, 'Evidence linking Arctic amplification to extreme weather in mid-latitudes' GRL 17 MAR 2012

abstract:

"Arctic amplification (AA) – the observed enhanced warming in high northern latitudes relative to the northern hemisphere – is evident in lower-tropospheric temperatures and in 1000-to-500 hPa thicknesses. Daily fields of 500 hPa heights from the National Centers for Environmental Prediction Reanalysis are analyzed over N. America and the N. Atlantic to assess changes in north-south (Rossby) wave characteristics associated with AA and the relaxation of poleward thickness gradients. Two effects are identified that each contribute to a slower eastward progression of Rossby waves in the upper-level flow: 1) weakened zonal winds, and 2) increased wave amplitude. These effects are particularly evident in autumn and winter consistent with sea-ice loss, but are also apparent in summer, possibly related to earlier snow melt on high-latitude land. Slower progression of upper-level waves would cause associated weather patterns in mid-latitudes to be more persistent, which may lead to an increased probability of extreme weather events that result from prolonged conditions, such as drought, flooding, cold spells, and heat waves."

http://onlinelibrary.wiley.com/doi/10.1029/2012GL051000/abstract (http://onlinelibrary.wiley.com/doi/10.1029/2012GL051000/abstract)

So it seems Jennifer Francis was the first to publish a plausible mechanism linking arctic amplification with unusual or extreme northern hemisphere weather events. 

Some might see this as an example of the serendipity in which scientists using different methods converge on similar conclusions.  And I suppose others might, er, disagree.  Whatever, this new work has made it into the Guardian as well as Science Daily and I hope this helps to make many more people aware that stuff that happens in the seemingly remote arctic can come uncomfortably close to home:

http://www.guardian.co.uk/environment/2013/feb/26/global-warming-planetary-airflow-extreme-weather-us-eu (http://www.guardian.co.uk/environment/2013/feb/26/global-warming-planetary-airflow-extreme-weather-us-eu)

Title: Re: Arctic Amplification and Extreme Weather
Post by: crandles on February 27, 2013, 12:49:36 AM
Thank you Stuart for answer and links.
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on February 27, 2013, 03:25:05 PM
I hadn't noticed that the BBC have an unsigned article on this, posted last Friday 22nd February.  It's quite typical of the standards we have come to expect of them.  They mention in passing that there are vast quantities of GHG's in permafrost, but go on to imply that the gravest danger is, ahem, subsidence . .

http://www.bbc.co.uk/news/science-environment-21549643 (http://www.bbc.co.uk/news/science-environment-21549643)
Title: Re: Arctic Amplification and Extreme Weather
Post by: ChrisReynolds on February 27, 2013, 09:05:09 PM
Thanks Born From The Void,

I've been pondering waves as the most likely cause of the new Greenland centred summer circulation pattern. If you check out the first graphic in this post you'll see a high over Greenland with a ring of lows around it.
http://dosbat.blogspot.co.uk/2012/09/summer-daze-2012.html (http://dosbat.blogspot.co.uk/2012/09/summer-daze-2012.html)

Why should this be?

Geopotential height still drops towards the Arctic, the Greenland high is a ridge in the geopotential height field, not the centre of activity. This means net air movement is still around the Arctic, so how can that gph ridge cause a pattern of lows around it?

Go into Google Earth (for example) and with reference to those lows start a ruler in the centre of Greenland. The lows are around 2800 to 3000km away from the centre of Greenland. Given all the different topographies, and the different zonal airflows I've been coming to the conclusion for some time that this pattern is driven by waves.
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on March 01, 2013, 12:59:47 AM
I've been pondering waves as the most likely cause of the new Greenland centred summer circulation pattern. If you check out the first graphic in this post you'll see a high over Greenland with a ring of lows around it.
http://dosbat.blogspot.co.uk/2012/09/summer-daze-2012.html (http://dosbat.blogspot.co.uk/2012/09/summer-daze-2012.html)

Thanks ChrisReynolds.  I'm in the UK too and I was very interested to read your Summer Daze posts.  At an intuitive level I feel that the weird weather we've been having - especially the colder winters since 2008/9 and last year's exceptionally wet summer - is related to events in the arctic by the kinds of mechanisms Jennifer Francis and now Petoukhov et al 2013 are suggesting, but I'm not qualified do any more than say it seems plausible to me.

On a completely different note, I see that Peter Sinclair's response to Petoukhov et al 2013 has been to post a clip from Jennifer Francis' recent video in which she carefully explains the mechanisms she believes connect artic amplification and changes to the jetstream and Rossby waves.  Then he posts a Reuters item and the Potsdam Institute press release about Petoukhov et al without further comment.  In the latter, one of the study authors is quoted as saying:

“Our dynamical analysis helps to explain the increasing number of novel weather extremes. It complements previous research that already linked such phenomena to climate change, but did not yet identify a mechanism behind it.”

I'm struggling to understand this, as Jennifer Francis so clearly did identify a mechanism!

http://climatecrocks.com/2013/02/27/new-research-links-climate-change-to-extremes/ (http://climatecrocks.com/2013/02/27/new-research-links-climate-change-to-extremes/)
Title: Re: Arctic Amplification and Extreme Weather
Post by: ChrisReynolds on March 01, 2013, 07:00:28 PM
Hi Stuart,

What Dr Francis (& Dr Vavrus) did was to identify a relationship between the speed of progression of rossby waves and Arctic warming. Which lead to a suggestion of linkage to persistent weather. I've not been able to get hold of a copy of the Petoukhov paper as yet, but from what I've read of it I don't think they're saying anything substantially different from Francis & Vavrus, they're just coming at the problem from a different angle. In the end it all boils down to what effect Arctic Amplification has on waves in the atmosphere and what impact this has on weather.

Likewise Dr Francis' explanation of winter boreal cooling was that increased and earlier Autumn snowcover cools the ground, snow being white reflects sunlight, the cooling this causes drives the temperature gradient south. And as the Jetstream is caused by the temperature gradient between polar air and mid latitude air, this carries the Jet south. Yet Cohen, who is arguably the leading expert on this issue, looks at connection between the snow cover and the polar vortex via waves in the atmosphere. What Dr Francis's explanation lacks is the explanation of how the autumn snow advance creates a delayed low AO which propagates the cooling in a distinctive pattern around the northern hemisphere. Dr Cohen's explanation of the propagation of waves in the atmosphere (produced before Dr Francis' explanation paraphrased above) fills in this added layer of detail.

But while amateurs and science aware members of the public can readily grasp Francis' explanation only professional meteorologists really get Cohen. So I think that Dr Francis often gives intuitive explanations which the public can grasp, but that there is a deeper truth. Just like there's a deeper truth behind the seibeck effect, engineers like myself will use our tables and test eqpt, a physicist adept with quantum mechanics will get the deeper truth. But that doesn't mean I can't help you fix problems in an industrial furnace's thermocouples and loggers. i.e. the less deep understanding still works.
Title: Re: Arctic Amplification and Extreme Weather
Post by: ChrisReynolds on March 01, 2013, 07:14:23 PM
I should add. I don't think Dr Francis is not getting the depth. She has said herself that she like to take simple approaches first (Weather & Climate Summit 2013 - where she explained the snow line and jet stream). But in one email exchange with her she outlined how changes in the jet stream were central to understanding the emergence of the Arctic Dipole. This is one reason I link the changes in NH blocking from 2003 to the emergence of the AD from 2003. Basically as I understood her the AD was an outcome of increased penetration of the jet into the Arctic - but I could be wrong, her explanation was complex and betrayed a far more subtle understanding of the issues than I have.
Title: Re: Arctic Amplification and Extreme Weather
Post by: Shared Humanity on March 01, 2013, 11:54:25 PM
I've been pondering waves as the most likely cause of the new Greenland centred summer circulation pattern. If you check out the first graphic in this post you'll see a high over Greenland with a ring of lows around it.

I've been watching this as well without a real clue. Is it possible that, with the loss of much of the sea ice, that Greenland is now playing the role that the Arctic Pole would have previously played in Northern Hemisphere weather patterns?
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on March 02, 2013, 02:18:56 AM
Hi Chris,

Many thanks for taking the time and trouble to give such a helpful reply.  I hadn't been able to access the Petoukhov et al paper until just now - thankfully it's open access and I've downloaded it from here:

http://www.pnas.org/content/early/2013/02/28/1222000110.full.pdf+html (http://www.pnas.org/content/early/2013/02/28/1222000110.full.pdf+html)

The PNAS Page with the abstract is here:

http://www.pnas.org/content/early/2013/02/28/1222000110 (http://www.pnas.org/content/early/2013/02/28/1222000110)

As expected it does contain a few equations and I need to take some time to overcome my natural tendency to find this stuff intimidating.  I know from experience I can usually get the drift but I'll print it out and I'll need to come back tomorrow to express anything sensible about it.

From the quickest of skims it's clear they are discussing Rossby Waves but using maths to look at them from quite a different angle to that of Francis & Varrus 2012 - two ways of looking at the same thing I tend to would say.  They don't refer to Jennifer Francis at all and the, "previous research that already linked such phenomena to climate change, but did not yet identify a mechanism behind it" is four different papers about the 2003 European heatwave.

The other extreme weather events they concentrate on are the Russian drought of 2010 and the European floods of 1997.  They have maps of 300 hPa windspeeds over Europe for these events, and similar maps of the whole northern hemisphere that also include the 2011 US summer heatwave.

They mention movies they've made to illustrate the paper but as seems almost inevitable the Potsdam Institute website tells me the page doesn't exist.  If anyone can locate them I'd be extremely grateful, the reference is given as:

33. Petri S (2012) Supplementary movies for quasi-resonant amplificationof planetarywaves and recent Northern Hemisphere weather extremes. Available at www.pik-potsdam.de/ (http://www.pik-potsdam.de/)∼petri/
planwaveresonance.html.

but searching the site for petri/planwaveresonance  produces "0 items matching your search terms" . . .
Title: Re: Arctic Amplification and Extreme Weather
Post by: ChrisReynolds on March 02, 2013, 11:42:00 AM
Thanks, it must have been made public yesterday US timezone.

I'll read it and get back to you later.
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on March 03, 2013, 12:43:27 AM
Hi Chris,

I expect most people are on the edge of their seats just now, amazed at the developing story of Crackopalypse.  I certainly am, and I'm grateful for your contributions to the discussion about that.  In comparison this topic isn't urgent so there's no need for a quick reply.

The paper is very much along the lines I'd imagined.  They are considering just the three events I metioned, the 2003 European heatwave, the 2010 Russian heatwave and the European flood of 1997.  A simplified explanation of their hypothesis might be that during the extreme weather events unusually persistent a high amplitude stationary Rossby Wave evolved and that this arises when a usually weak wave response is magnified by something they call "quasiresonance".  They propose formulae for this which I assume are derived from or related to accepted Rossby Wave theory. In their discussion they mention that there are some indications that arctic amplification amplification produces more favourable conditions for this.

In the conclusion they say, "If the observed increasing number of summer months with high-amplitude wave numbers m=6, 7, and 8 indeed is the result of ongoing global warming, then we have described a possible dynamical mechanism for how global warming might contribute to future extreme summer events."  Rather ominously they also link this mechanism with some of the events of 2012, "The data and results we present suggest that atmospheric conditions already might have changed to the extent that the considered quasiresonant wave amplification may occur rather frequently. The most recent example might be the destructive heat waves in the United States and southern Europe accompanied by catastrophic floods in China and Japan in June–July 2012"

But I entirely agree this is deep stuff and my lack of mathematical ability means that I'm unable to appreciate the subtleties of this paper.  It's very interesting that you felt from Jennifer Francis' emails that, "her understanding was complex and betrayed a far more subtle understanding of the issues than I have."  She comes across as an exceptionally competent lady and I'd not be in the least surprised if the paper in which she publishes the results she described in the video turns out to be too subtle for me.

Anyway, to my own rather simplistic amateur way of thinking it does seem that Petoukhov et al are using a different method to come to conclusions that are similar to those of Dr Francis, and that this is actually very encouraging, particularly as Stefan Rahmstorf is second author. It seems very likely that it is possible to link global warming with at least some extreme weather events, and that what's happening in the arctic plays an important role in this.  Your ideas about how the AD relates to this is another fascinating aspect I'll be very interested to follow.

BTW  I still can't find the movies mentioned in the reference - maybe they're delayed in a similar way to the paper itself was.
Title: Re: Arctic Amplification and Extreme Weather
Post by: ChrisReynolds on March 03, 2013, 09:44:13 AM
I'm now wondering if they're both talking about different mechanisms...

As you say it's not urgent. I'm posting a blog post today about the Beaufort fracturing, so won't get to read that paper. I do need some time watching films today. But I'll get back to you in a day or two.

Oh, and my maths isn't great, which is a problem in this area.
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on March 04, 2013, 09:14:49 AM
Hmm . . .  In a new report today from the Inter Press Service co-author of Petoukhov et al 2013 Hans Joachim Schellnhuber is quoted as saying, “(Our research) complements previous research that already linked such phenomena to climate change”. Quite a change of emphasis. The same article quotes Jennifer Francis herself making very sensible comments on the findings of the new paper:

http://www.ipsnews.net/2013/02/killer-heat-waves-and-floods-linked-to-climate-change/#sthash.Txrd2fyy.dpuf (http://www.ipsnews.net/2013/02/killer-heat-waves-and-floods-linked-to-climate-change/#sthash.Txrd2fyy.dpuf)
Title: Re: Arctic Amplification and Extreme Weather
Post by: ChrisReynolds on March 04, 2013, 09:25:51 PM
Stuart,

I'm ploughing through the Petoukhov paper now. But I want to read Francis & Vavrus again. What I'm thinking initially is that Francis & Vavrus have found the connection, the Petoukhov paper may be elucidating the mechanism. However the maths of this paper is going way over my head, I conceptually follow waveguides and standing waves, degree in Electronics, but a lot of the rest is head bending!

BTW, did you read my blog post on Blocking events? This all seems to be tying in with that as well.
http://dosbat.blogspot.co.uk/2013/01/northern-hemisphere-blocking.html (http://dosbat.blogspot.co.uk/2013/01/northern-hemisphere-blocking.html)
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on March 05, 2013, 10:49:52 AM
Chris, I quite agree this is head bending!  I need to do more reading, and also re-read Francis and Varrus and watch the videos again before I can say anything more that's useful about this.   

Edited to remove repetition.
Title: Re: Arctic Amplification and Extreme Weather
Post by: Shared Humanity on March 12, 2013, 04:44:43 PM
Three climate scientists, Charles H. Greene, Jennifer Francis and Bruce C. Monger wrote an article in the scientific journal "Oceanography"

http://www.tos.org/oceanography/ (http://www.tos.org/oceanography/)

.....that stated a "warming global climate that melts sea ice in the Arctic is driving changes to the jet stream — upper atmospheric winds that shape weather across North America — and helped create the conditions that mutated Hurricane Sandy into a hybrid storm".

Truly encouraging is the fact that mainstream media has picked this up and is reporting it. It is not by accident that a New Jersey newspaper picked this one up.

http://www.nj.com/news/index.ssf/2013/03/hurricane_sandy_arctic_ice.html (http://www.nj.com/news/index.ssf/2013/03/hurricane_sandy_arctic_ice.html)

I am sure that any additional media which speaks directly to an affected area would do the same if they had the research in front of them. Would it make sense for there to be an active effort here to steer local media to relevant research. Any research speaking about drought impacts in the plains would likely get reported in newspapers in this region. We could build political and policy momentum by doing this.
Title: Re: Arctic Amplification and Extreme Weather
Post by: werther on March 13, 2013, 11:06:02 AM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FAquariussalinity04032012small_zps610e85af.jpg&hash=82c3c0d6b07319ad25b89719827df1f1)
Salinity on 4 March ’12…
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FAquariussalinity04032013small_zpsdf38b221.jpg&hash=c6e1709b9a4a0e69fcb9cb652992cb32)
And on 4 March ’13…

Thinking about teleconnections, the OSDPD SST-maps I posted earlier (on the ENSO-thread)…

Combining that with the decadal NCEP/NCAR sequence I made since September ’12.
Noting the large fresh water release last summer from the GIS (700 km3), the Arctic Sea Ice and the growing amount from Antarctica…

Then including the latest info we have on SIA (Weddell Sea/Antarctica, Kara-Barentsz Sea/Arctic) and PIOMAS.

I thought there might be another clue in the salinity content of the upper oceans and dove into the Aquarius data, hence the maps above.

I have this concept in my mind. In short, could it be that an anomalous fresh water ‘pulse’ is the basis for the erratic behaviour in oceanic/atmospheric patterns?
It doesn't have to be a large scale THC change, just an erratic glitch for several months. Temporarily affecting FI influx of NAWater into the Barentsz Sea and teaming up with the largely AO-negative Arctic winter.
And producing yet another cold snap through Europe...
Title: Re: Arctic Amplification and Extreme Weather
Post by: Bruce Steele on March 13, 2013, 05:00:28 PM
Werther, The salinity change in the Barents Sea is pronounced 2012-2013. I found this paper which describes changes in flow rates for a bifurcation of atlantic water transport into the arctic. If the strength of the flow has switched from the Barents back to the Fram Strait would it also allow a surface freshening of the Barents?                  NATURE COMMUNICATIONS | ARTICLE    OPEN
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One mechanism contributing to co-variability of the Atlantic inflow branches to the Arctic

Vidar S. Lien,    Frode B. Vikebø    & Øystein Skagseth
AffiliationsContributionsCorresponding author
Nature Communications 4, Article number: 1488 doi:10.1038/ncomms2505
Received 05 November 2012 Accepted 16 January 2013 Published 12 February 2013
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Abstract
Abstract Author information Supplementary information
The two-branched inflow of warm and saline Atlantic Water to the Arctic is the major contributor of oceanic heat to the Arctic climate system. However, while the Atlantic Water entering the Arctic through the Fram Strait retains a large part of its heat as it flows along the Arctic continental slope, the branch flowing through the shallow Barents Sea releases a substantial amount of heat to the atmosphere. Hence, the pathway of the Atlantic Water into the Arctic to a large degree determines the short term fate of its heat. Here we show events in which the relative strengths of the two branches are affected by wind-induced Ekman-transport off the northern Barents Sea shelf. The resulting decrease in sea surface height induces a cyclonic circulation anomaly along the slope encircling the northern Barents Sea shelf area, which enhances the flow through the Barents Sea while weakening the branch flowing along the Arctic continental slope.
Title: Re: Arctic Amplification and Extreme Weather
Post by: Bruce Steele on March 13, 2013, 08:14:17 PM
http://www.google.com/url?q=http://www.nature.com/ncomms/journal/v4/n2/fig_tab/ncomms2505_F3.html&sa=U&ei=BMxAUeDUNoONygGmkIFg&ved=0CBgQFjAA&usg=AFQjCNHL94M9YyFZJd_cX7tnSCXwERXiHg. (http://www.google.com/url?q=http://www.nature.com/ncomms/journal/v4/n2/fig_tab/ncomms2505_F3.html&sa=U&ei=BMxAUeDUNoONygGmkIFg&ved=0CBgQFjAA&usg=AFQjCNHL94M9YyFZJd_cX7tnSCXwERXiHg.)                               Here is a link to the flow rates in the Barents paper.  I should have asked if salinity changes should be expected in the Barents Sea depending on changes in these flow rates?
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on March 26, 2013, 01:24:45 AM
Neven has already mentioned this on the Blog, but there's an article in the Guardian this evening that links both hot and cold extreme weather events such as the current cold spell in the UK and northern Europe to disappearing arctic sea ice.  It's on the front page, is among their top five most-viewed stories and already has more than 500 comments.  Environment Editor John Vidal devotes the first part to Jennifer Francis' work, and quotes Vladimir Petoukhov in support of her viewpoint.  A couple of the comments link to Dr Francis' videos.  I'm pleased that at last this work is getting the prominence that I for one, feel it most certainly deserves:

http://www.guardian.co.uk/environment/2013/mar/25/frozen-spring-arctic-sea-ice-loss?fb=native&commentpage=1#start-of-comments (http://www.guardian.co.uk/environment/2013/mar/25/frozen-spring-arctic-sea-ice-loss?fb=native&commentpage=1#start-of-comments)
Title: Re: Arctic Amplification and Extreme Weather
Post by: ChrisReynolds on March 26, 2013, 10:13:30 PM
Stuart,

I've not forgotten our discussion that's on hold. I had been hoping that I'd get the chance to switch focus onto this matter, but matters around sea ice, and some new data I've extracted from PIOMAS gridded data, not to mention my day job, keep getting in the way. Sorry!
Title: Re: Arctic Amplification and Extreme Weather
Post by: StuartC on March 27, 2013, 01:49:02 AM
Chris,

Thanks for that - I haven't forgotten either!  My personal method of following and trying to learn from global warming news is pretty time-consuming and I too have rather put it on hold. Also, I'm rather stuck with Petoukhov et al.  I've read a couple of differing interpretations of their idea of "planetary waves" and I'm still not sure what they mean when they assign different numbers to them (anyone??).  But it seems to me that Vladimir Petoukhov endorsing Jennifer Francis' views to John Vidal is a good sign.  As well as being fascinating - and pretty scary - I think this work relating weather extremes to what's going on in the arctic is most important, so I certainly will come back to this.
Title: Re: Arctic Amplification and Extreme Weather
Post by: Steve Bloom on April 11, 2013, 09:27:21 AM
Stuart, the Petoukhov et al. movies are there now at http://www.pik-potsdam.de/~petri/planwaveresonance.html (http://www.pik-potsdam.de/~petri/planwaveresonance.html)

For some reason your link had an html hiccup when I copied it, replacing the squiggle with a square, but it worked fine when I put the squiggle back.

Thanks for the pointer to them. 
Title: Re: Arctic Amplification and Extreme Weather
Post by: Shared Humanity on May 03, 2013, 05:50:56 PM
There has been a stationary front across the Mississippi River in the U.S. for the past 3 days delivering record breaking snowfalls across Iowa and Minnesota. These kinds of stalled fronts are unusual but have been occurring more and more frequently over the past few years. Normally a front like this would have already moved across the eastern half of the U.S. and entered the Atlantic.

In the last 12 hours it has begun to move slowly to the northwest! This is not simply unusual but very weird. What does the northern hemisphere jet stream look like?
Title: Re: Arctic Amplification and Extreme Weather
Post by: Shared Humanity on May 03, 2013, 05:54:01 PM
Meanwhile a mass of heavy rain and thunderstorms has been planted over Florida for the same three days causing flooding across the state.
Title: Re: Arctic Amplification and Extreme Weather
Post by: ritter on May 03, 2013, 06:00:12 PM
Well, we were promised droughts and floods. Unfortunately, it's looking like science got that right.
Title: Re: Arctic Amplification and Extreme Weather
Post by: John_The_Elder on May 04, 2013, 03:06:59 AM
This is the Jet Stream moving that snow north west.
http://squall.sfsu.edu/gif/jetstream_init_00.gif (http://squall.sfsu.edu/gif/jetstream_init_00.gif)
Title: Re: Arctic Amplification and Extreme Weather
Post by: John Batteen on May 06, 2013, 09:11:03 PM
I live in Minnesota, and I've been noticing an ever increasing number of occasions like this.  The jet stream has been more or less locked in place overhead, brutalizing us with arctic outbreaks over and over again.  The pattern changed about midway through February and has stuck ever since.  I'm hoping that in the transition to summer we get a change.

There are minor variations around a theme, but it seems that once the jet stream has picked a favorite spot, it comes back to it time and time again until the pattern changes.
Title: Re: Arctic Amplification and Extreme Weather
Post by: BornFromTheVoid on June 10, 2013, 11:28:15 AM
Jeff Masters links the flooding in Europe to Arctic Amplification
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2432 (http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2432)

Sorry if it's been posted elsewhere.
Title: Re: Arctic Amplification and Extreme Weather
Post by: J Cartmill on November 26, 2013, 01:16:59 PM
Article at Fairfax climate watch about research being conducted by Paul Mayewski, director of the University of Maine's Climate Change Institute.

“We just experienced an abrupt climate change event in the Arctic,” Mayewski said. “Portions of the Arctic have warmed as much as 9°F in the last few years. This is possibly the most dramatic event of the last several thousand years and a harbinger of more abrupt events in onset of drought, storm frequency and heat waves to come.”

http://www.fairfaxclimatewatch.com/blog/2013/11/the-rise-and-fall-of-the-westerlies.html (http://www.fairfaxclimatewatch.com/blog/2013/11/the-rise-and-fall-of-the-westerlies.html)
Title: Re: Arctic Amplification and Extreme Weather
Post by: JimD on November 26, 2013, 04:33:01 PM
J

Thanks.  I forget to go by that blog sometimes and it has lots of good work.
Title: Re: Arctic Amplification and Extreme Weather
Post by: werther on December 22, 2013, 01:39:48 PM
Time seems fit to re-vitalise this thread....

In the chase for extreme or ‘wacky’ weather I’m trying to notice ephemeral patterns that could later on be pointed to as being defining.
Could this be such a one?

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FPolarvortex19122013small_zps8999d628.jpg&hash=ede9bd98af2372ea0ee097cc26bf778c)

This is a combination of 300Mb jet, 500Mb ridges and troughs over the NH on 19 december. It looks like this pattern is having an effect on the sea ice, now that the ‘normal’ fall extent growth has almost been completed. It could well be from now on SIE/SIA and Volume will get in line with the ’07-’12 years.
I invite the fellow posters to discuss whether this pattern is anomalous. I haven’t studied this, I’m relying on my “gut-feel” having brooded over lots of this sort of graphs through the last three years.

There are at least three very deep trough incursions visible; representing Rossby-waves with large amplitude. The Polar Vortex has completely shifted away from the Pole, centering now on Foxe Bay and the Polar Circle (in green). It has a persistent trough-arm over S.Greenland, Iceland up to Scotland and another one, likely getting cut-off, into NW Siberia.
The main jetstream runs almost perfectly on the Tropic of Cancer in Eurasia, right into the W Pacific. It defines the tropics and the Hadley cell-boundary on 300Mb. North of it, there’s a vast half circle, spanning most of N. Eurasia and part of the Arctic Ocean, that has only small jet-features, even though the spikes of at least three Rossby-waves are running through it. While they create weather and certainly synoptic scale events of importance, it seems very well possible to suggest that the Polar and Ferrell cells have merged here.

The American side is quite different. Two Rossby-waves, that have a preferred hold  or re-appearance over the same regions for months now, rotate under a wildly kinked Jet, drawn by or promoting the cold Vortex over NW Canada . This jet combines the extratropical and polar jet properties and lead to the violent weather contrasts in the USA-CONUS. The Ferrell cell is virtually non-existent here.

The propagation of the merging cells could get it’s particularities through the large-scale geomorphology of the NH. The Jet over Eurasia follows the west-east stretch of mountain ranges that reach right into mid-troposperic altitudes. The ‘kinky’ pattern on the other side is probably influenced through two massive Oceans and their anomalously warm waters and the bold north-south Rocky Mountain barrier.

Where will this go? The suggestion is that the Polar Vortex is contracting.

While it promotes some very cold weather in N America on 1000Mb, the temps through the troposphere as a whole over the NH are not cold. It ‘ll be interesting to check this with NCEP/NCAR through this winter.
This ‘not being very cold’ fits right into an analysis of the effects of smaller temp differences between the Tropics and the Poles. The relentlessly rising atmospheric levels of greenhouse gasses promote this.
The Rossby wave positions and amplitudes tend to resp. re-appear ‘stuck’ and get larger, not necessarily ‘more energetic’. I mean, they have been transferring massive amounts of energy over the past years, but while diminishing the Tropic-Pole temperature difference, their individual properties are not strikingly different from the climatologic trends. The enormous lengths of the ‘spaghetti’-line fronts between these features promote much more mixing of the energy at hand, that’s what makes the difference.

Taking this a bit further (and closing this post), the persistent low over the Arctic last summer fits into this pattern of merging cells. I would not be surprised to see this pattern continuing into a sort of ‘phase 23:40 hours’-global warming period, in which there would seem to be a certain pause in atmospheric boundary layer temp rise and Arctic sea ice melt-down.
Title: Re: Arctic Amplification and Extreme Weather
Post by: Shared Humanity on December 22, 2013, 04:59:49 PM
While that kinked jet stream has brought cold air to North America, it has also created a persistent stream of warm moist air coming from the Gulf and blanketing the eastern half of the  continent. We have had weeks of cloudiness and precipitation of all types, rain, sleet, freezing rain and snow.
Title: Re: Arctic Amplification and Extreme Weather
Post by: Shared Humanity on December 22, 2013, 05:15:58 PM
And this is what we get when this kinked jet stream sits over North America.

http://www.huffingtonpost.com/2013/12/21/new-york-city-temperature-record_n_4487182.html (http://www.huffingtonpost.com/2013/12/21/new-york-city-temperature-record_n_4487182.html)

These same loopy jet streams are altering the nature of winter precipitation. Winter ice storms which use to be prevalent in Tennessee and parts south are now shifting north, periodically replacing what was previously heavy snow.

http://www.huffingtonpost.com/2013/12/22/ice-storm-new-york-vermont_n_4488692.html (http://www.huffingtonpost.com/2013/12/22/ice-storm-new-york-vermont_n_4488692.html)
Title: Re: Arctic Amplification and Extreme Weather
Post by: Sigmetnow on January 07, 2015, 03:17:27 PM
Dr. Francis has a new paper out with more evidence of this trend.
Quote
New metrics and evidence are presented that support a linkage between rapid Arctic warming, relative to Northern hemisphere mid-latitudes, and more frequent high-amplitude (wavy) jet-stream configurations that favor persistent weather patterns. We find robust relationships among seasonal and regional patterns of weaker poleward thickness gradients, weaker zonal upper-level winds, and a more meridional flow direction. These results suggest that as the Arctic continues to warm faster than elsewhere in response to rising greenhouse-gas concentrations, the frequency of extreme weather events caused by persistent jet-stream patterns will increase.
http://iopscience.iop.org/1748-9326/10/1/014005 (http://iopscience.iop.org/1748-9326/10/1/014005)
Title: Re: Arctic Amplification and Extreme Weather
Post by: ritter on January 07, 2015, 07:13:10 PM
Dr. Francis has a new paper out with more evidence of this trend.


What happens in the Arctic doesn't stay in the Arctic. It's one of those things I try to convey to people--even though it's half the world away, it's going to smack us upside the head. Thanks for the link!
Title: Re: Arctic Amplification and Extreme Weather
Post by: Niall Dollard on September 04, 2020, 06:49:04 AM
Arctic Amplification.
Title: Re: Arctic Amplification and Extreme Weather
Post by: El Cid on September 04, 2020, 09:08:49 AM
THIS is a better representation of Arctic Amplification (last 5 yrs vs 1960-1990 average, first pic: annual and second pic: only winter).

Couple of things:

1. Winter is more amplified than other seasons
2. There is NO WACC. Very warm Arctic and still pretty warm continents. During winter Arctic is 2-4 C + , and all of Russia and almost all of Europe is above 2 C +. NA is 1-2 C +.
3. As Siberia warms up fast and the Siberian High has a major effect on winter and early spring weather in Europe, European winters are becoming milder.
4. The S.Greenland-North.Hudson-CAA region is possibly becoming the new pole of Cold but that only means they are not warming, not that they are cooling down
Title: Re: Arctic Amplification and Extreme Weather
Post by: bbr2315 on September 04, 2020, 06:02:51 PM
THIS is a better representation of Arctic Amplification (last 5 yrs vs 1960-1990 average, first pic: annual and second pic: only winter).

Couple of things:

1. Winter is more amplified than other seasons
2. There is NO WACC. Very warm Arctic and still pretty warm continents. During winter Arctic is 2-4 C + , and all of Russia and almost all of Europe is above 2 C +. NA is 1-2 C +.
3. As Siberia warms up fast and the Siberian High has a major effect on winter and early spring weather in Europe, European winters are becoming milder.
4. The S.Greenland-North.Hudson-CAA region is possibly becoming the new pole of Cold but that only means they are not warming, not that they are cooling down
WACC happens in spring-summer-fall. For now.
Title: Re: Arctic Amplification and Extreme Weather
Post by: El Cid on September 04, 2020, 09:15:55 PM
WACC happens in spring-summer-fall. For now.

NOPE.

Showing same as above but for spring, summer and autumn. Not a sign of WACC. Picture is same as winter: very warm Arctic, warm continents. These are the facts, everything else is speculation
Title: Re: Arctic Amplification and Extreme Weather
Post by: bbr2315 on September 04, 2020, 09:24:38 PM
WACC happens in spring-summer-fall. For now.

NOPE.

Showing same as above but for spring, summer and autumn. Not a sign of WACC. Picture is same as winter: very warm Arctic, warm continents. These are the facts, everything else is speculation
I disagree. Your selection includes super Nino 15-16. If you picked 14, 17, 18, 19, 20, it would be clear.

Here is 18, 19, 20 for April, May, June.

And, April alone.

The anomalies retreat upslope through the season. So by June and July, it is the Himalayas and not the Great Plains that are purple and blue.

The worse this gets, the more purples and blues will begin appearing in May and June, and they will be MORE SEVERE than what is already happening in April.
Title: Re: Arctic Amplification and Extreme Weather
Post by: bbr2315 on September 04, 2020, 09:31:37 PM
And 2020. Yikes. Very bad!

I know I sound a bit combative here but I am not trying to be rude. The blended years since 2012 do not show the WACC-y signal since it is not yet consistent EVERY year but it has been since 2017 I believe.

2013 and 2014 were when it first really appeared after the 2012 "event", the 2015 Nino resulted in its pause through 2016, but it resumed in 2017 and has been seemingly strengthening annually since. Maybe there will be another reset next year -- maybe not -- but this seems to be worsening and 2020 is the worst yet, IMO.
Title: Re: Arctic Amplification and Extreme Weather
Post by: harpy on September 04, 2020, 09:46:34 PM
Please define WACC. 
Title: Re: Arctic Amplification and Extreme Weather
Post by: bbr2315 on September 04, 2020, 09:47:29 PM
Please define WACC.
Warm Arctic Cold Continents.
Title: Re: Arctic Amplification and Extreme Weather
Post by: oren on September 05, 2020, 12:56:24 AM
You only pick certain months, in certain years, and compare to a warm baseline (1981-2010), in order to show the signal you are looking for. This means there is no such widespread trend of WACC for the time being.
Title: Re: Arctic Amplification and Extreme Weather
Post by: sark on September 05, 2020, 01:08:17 AM
literally any charts you run right now show a trend.  what is it you would like to see?
Title: Re: Arctic Amplification and Extreme Weather
Post by: oren on September 05, 2020, 01:36:10 AM
Is there a long term chart showing the continents getting absolutely colder as the Arctic is getting warmer? Or, as El Cid has shown, that it's only the continents warming less than the Arctic?
Title: Re: Arctic Amplification and Extreme Weather
Post by: sark on September 05, 2020, 02:36:54 AM
at this point?  probably not... I guess you'd have to help me hone in on the prediction in question and see if it's a testable hypothesis.  Is the question, will the WACC trend hold forever? 
Title: Re: Arctic Amplification and Extreme Weather
Post by: sark on September 05, 2020, 03:00:12 AM
When those articles were published, it was true.  Now?

OK, let's just compare a 5 year average from 2000-2020 of DJF surface temperature anomalies +/- 1.5... like an autosquint function... exaggerated.  Compared to the 1979-2000 average.  We're talking about articles published back a few years ago.  in the last few years the cooler trend anywhere is pretty much annihilated.

click to run
Title: Re: Arctic Amplification and Extreme Weather
Post by: El Cid on September 05, 2020, 07:44:29 AM
You only pick certain months, in certain years, and compare to a warm baseline (1981-2010), in order to show the signal you are looking for. This means there is no such widespread trend of WACC for the time being.

Exactly my thoughts. We must compare the last years to the "pre-globalwarming" years. The 1980-2010 "baseline" already contains many very warm years obviously.

Here is a comparison of the past 10 (no handpicking) years (springs only) vs 1950-80. NO WACC. Second pic: 2011-2020 vs  2001-2010. You can see that the pole of cold is pushed into the Hudson-S.Greenland region. This certainly shows some WACC-yness. With a constantly warm Bering and Barents the jetstream is likely becoming curvier - I agree. However let's not forget that all those cold outbreaks are less cold than they used to be, simply because the air above the Arctic is warmer. So yes, there are places where there are more cold outbreaks but the outbreaks are likely not as cold as previously could have been

And net-net, as you can see on third picture (2011-20 springs vs 2001-2010) midlatitudes ARE warmer even vs 2001-2010), so this is more a local effect

Title: Re: Arctic Amplification and Extreme Weather
Post by: oren on September 05, 2020, 09:06:27 AM
Thank you sark and El Cid.
Title: Re: Arctic Amplification and Extreme Weather
Post by: kassy on September 05, 2020, 05:12:53 PM
And 2020. Yikes. Very bad!

I know I sound a bit combative here but I am not trying to be rude. The blended years since 2012 do not show the WACC-y signal since it is not yet consistent EVERY year but it has been since 2017 I believe.

The picture shows a cold America. Continents is multiple and Eurasia is not that cold. Hence is does not show the signal.
Title: Re: Arctic Amplification and Extreme Weather
Post by: wdmn on September 05, 2020, 05:18:42 PM
I'm very interested in the "cool" Spring signal in North America. Is it just noise?

In any case, it's a hurdle for educating people on climate change. People here around the Great Lakes notice it when Spring starts late, or when we get old style extremely cold winters.
Title: Re: Arctic Amplification and Extreme Weather
Post by: gerontocrat on September 05, 2020, 05:21:47 PM
And 2020. Yikes. Very bad!

I know I sound a bit combative here but I am not trying to be rude. The blended years since 2012 do not show the WACC-y signal since it is not yet consistent EVERY year but it has been since 2017 I believe.

The picture shows a cold America. Continents is multiple and Eurasia is not that cold. Hence is does not show the signal.
https://journals.ametsoc.org/jcli/article/33/18/8069/348406/Severe-Cold-Winter-in-North-America-Linked-to
Severe Cold Winter in North America Linked to Bering Sea Ice Loss
Quote
Our study under the present climate shows that severe cold winters in North America are linked to Bering SIA loss via the negative ALO–ANA pattern. In the near future, with little or no sea ice in the Bering Sea, this negative ALO–ANA pattern may occur more frequently, or a completely different climate mode may appear. To predict severe cold winters in North America under global warming, it will be necessary to model regional and general climate systems with little or no sea ice.
Title: Re: Arctic Amplification and Extreme Weather
Post by: kassy on September 05, 2020, 05:43:36 PM
I'm very interested in the "cool" Spring signal in North America. Is it just noise?

In any case, it's a hurdle for educating people on climate change. People here around the Great Lakes notice it when Spring starts late, or when we get old style extremely cold winters.

See the article by gerontocrat above.

And i think there is also another reason. On the ASIB wayne used to discuss things as were the cold poles went. In the old days it could be on the Arctic ice or travel over it and hop to Siberia.

The last couple of years the American side near the Arctic is always much colder and as discussed on the Melt Season thread yesterday or today it seems the arctic is leaking air cold and that is going south into America.

For climate change you should tell them about the world. But it´s hard to explain that 0,5 C global really matters. 
Title: Re: Arctic Amplification and Extreme Weather
Post by: El Cid on September 05, 2020, 06:37:20 PM
I'm very interested in the "cool" Spring signal in North America. Is it just noise?

I think it is a temporary and local effect. I drew a very basic sketch showing probably what is going on (very unscientific, layman terms, sry for that).

On the chart we can see 2019 vs 1995 (I could have picked any earlier years as well). As the Bering/Chukchi and the Barents is much warmer and ice free for a very long time, warm air can intrude here (creating the Alaskan Ridge and European warm weather) shown by red. However, this pushes cold (blue) out of the Arctic which could go to Siberia or Canada. Unfortunately for Canadians, the shallow Siberian seas are usually also very warm lately (green) as evidenced by late freeze-ups, so the cold air is pushed into Canada.

This might not be very scientific but I think it is more or less true
Title: Re: Arctic Amplification and Extreme Weather
Post by: kassy on September 05, 2020, 06:56:27 PM
I like that (although only a layman to so FWIW).

Title: Re: Arctic Amplification and Extreme Weather
Post by: gerontocrat on September 05, 2020, 07:03:45 PM
As the Bering/Chukchi and the Barents is much warmer and ice free for a very long time,

The attached graphs show the (not so) gradual and continuing transformation of these seas into open water seas from icy deserts.
Title: Re: Arctic Amplification and Extreme Weather
Post by: El Cid on September 05, 2020, 08:04:50 PM
That is great gerontocrat, as these charts underscore that the Chukchi/Bering side has fundamentally changed during the past 5-6 years.
The Barents actually changed after 2007, not lately.

thanks
Title: Re: Arctic Amplification and Extreme Weather
Post by: sark on September 06, 2020, 01:05:55 AM
Summer polar amplification has never really been seen to this extent, as in the past 2 years.  And, in 2020, we have an appearance of the third pole of cold?

Unfortunately there is huge model variance on what is actually going on over the Tibetan Plateau this Summer, and continuing still today...

Would someone check the ERA or MERRA records to see what is being reported in this region?  surface temperature anomaly, SLP anomaly, 500mb temps & heights even...

Specifically May - August of 2020 is very interesting as there is still model variance on what is even going on here.