Temps

Air temperatures

One thing I failed to mention in the last SIE update and promised to get back to, is the fact that temperatures have been anomalously low on the Canadian side of the Arctic for quite a while now, or to be more precise: ever since the start of April, when the Arctic Oscillation that has been positive since the start of the year, became even more positive. It still hasn't let the Arctic out of its grip, which makes for vast cloudless regions over Greenland and the Canadian Archipelago. Great for clear satellite images, and obviously great for ultra-freezing temperatures.

I decided to go to the Daily Mean Composite page, compiled by the Physical Science Division of NOAA's Earth System Research Laboratory, that came in so handy when writing the End Zone series at the end of last year's melting season, and compare this year's April 1st - April 15th period with other years.This is the mean composite image for this year:

 This is how it looks like for other years (click for a larger image):

At a first glance it looks as though this year is less cold than previous years, as the dark purple blob is much smaller than in previous years. But that's because the scale is different! Except for 2009 the scale doesn't go below -15 degrees C, but this year the scale goes all the way down to -25 degrees C (unfortunately this happens a lot with these daily mean composite images, which makes comparing a tad more difficult). So at a second glance it looks as though this year has been 5-10 degrees C colder in the past few weeks than previous years in the period 2005-2010.

It's safe to say things have lately been mighty cold up there around Greenland and the Canadian Archipelago, keeping the Nares Strait frozen solid and thickening the ice between the Canadian Arctic islands some more before the melting season gets going. Will it be enough to keep the Northwest Passage from opening up this year? Somehow I don't think so, but it's too early to tell.

Sea surface temperatures

As sea surface temperatures probably play an even larger role in this, I decided to take a look at the SST anomalies for April on the EORC-JAXA webpage. This is the current situation:

And this is how things looked in April 2005-2010 (click for a larger image):

Mind you, this year's SST anomaly map only covers the first half of April, whereas the other maps are for the whole month. Except for the very red Baffin/Newfoundland Bay in 2010, 2011 doesn't seem to be very different from other years. So far it looks very similar to 2005 (which is the only year in the 2005-2011 period that had an anomalously warm sea surface in the Bering Sea).

Keeping an eye on this gives us an idea how things compare to previous years and what might be expected the coming melting season, especially if we combine it with comparisons of sea ice thickness maps (I'm still waiting for TOPAZ to update, so I can compare it with PIPS). I'll do an update in a few weeks time. In the meantime: speculate!

Comments

[Lord Soth]

These graphs show the temperature at the 925 mb gradient, which is equivalnet to 800 meters, so you may want to add 5 degrees to get the average temperture on the surface.

Up until January, this area has been much warmer, and has been on average in Febuary and March, so two cold weeks at the end of the freeze season, will have very litte impact, as the damage has already been done.

[Peter Ellis]

unfortunately this happens a lot with these daily mean composite images, which makes comparing a tad more difficult

So, uh, check the tick box to graph the anomaly instead of the raw data? Another handy function is to restrict the plot to latitudes north of 60 degrees to zoom in on the area of interest.

For example: http://1.usa.gov/hwPK3v

[Neven]

Lord Soth, it was relatively warmer, but still very cold. I would think a few weeks of extreme cold right at the end of the winter season gives the ice a bit extra strength. I mean, look at Nares.

There was a reason I used 925mb last year instead of 1000mb (which would amount to around 100 meters), but I can't remember what it was.

Thanks for the anomaly-box-tip, Peter. I didn't know it could be that simple. Although, on second hand, I believe the scales still 'jump' from one year to the next. But I'm probably doing something wrong.

WRT the latitudes: I have lowest lat 60 and highest lat 90, but the entire Northern Hemisphere is shown. Could you tell me how to exactly restrict the plot to latitudes north of 60 degrees? Thanks, that'll improve the next round of comparisons considerably.

[Peter Ellis]

Your settings are fine - but they only take effect if you set "Region of Globe" to "Custom".

[Neven]

Great, that does the trick. Thanks a lot!

[Lord Soth]

If you follow the above link, and click go back one day, you will soon reach a period where the abnormity was 5 to 10 warmer than average.

I'm sorry, but I think we are just looking at short term weather here.

It would be nice to get a graph for the period of November 15 to April 15., for this year and the past several years also. This would give us a much better idea of the abnormity.

Also, cold tempertures in the early spring would probably have little to no impact on thick ice covered with snow. However it would cause the water between the flows to freeze and thicken.

However those vast cloudless areas are soon going to contribute to solar loading.

It's is interesting however. It would also be interesting to see the corolation between temperature anomalities in the hight arctic and the AO phase.

[Bfraser]

Speaking of TOPAZ, something strange is going on (perhaps it means that are getting ready to come back to life, perhaps it means they are falling apart). First, the URL for getting the archival data no longer works:

http://topaz.nersc.no/thredds/dodsC/topaz/mersea-ipv2/arctic/tmipv2a-class1-b-be.html

Second, when I try to get today's images at:

http://topaz.nersc.no/topazVisual/matlab_static_image.php

Instead of the usual "No Image available for temperature at the Dtae : 20110419 for the Depth : 0005, try different options........"

I got a different message (something about a directory not existing) but now the original message is back.......

[Neven]

I've mailed someone at TOPAZ (the mail address at the bottom) a few days back, but haven't received an answer yet.

[Artful Dodger]

... too many people downloading 4 GB of data?

[Erimaassa.blogspot.com]

Speculation... Guessing either Pacific NW gets a really windy and wet summer (even more than usual) triggering some landslides or the big blob of lukewarm water south of Aleuts (on a more northern location than in previous years) enters Arctic giving 2007 record minimum a hard time. I'm somewhat surprised to see north Atlantic a bit cooler than previously, but maybe the warmth that lacked in Europe this winter is in Texas right now.

[idunno]

Hi Neven et al,

Sorry I have been busy offline, and have slightly lost the plot...

A couple of interesting things I've recently stumbled across...

There is a new page up on Inuit traditional knowledge about sea ice @

http://sikuatlas.ca/index.html

And a journo/blogger called Cory Morningstar has posted 4 very long, occasionally rambling and absolutely spot-on pieces on the methane bomb @

http://theartofannihilation.com

They are filed under "The Real Weapons of Mass Destruction - Methane, etc".

I should say that Ms Morningstar's prognosis is not for the faint-hearted. And that I think personally she's quite correct. Hope we're both wrong.

[D S]

Neven, on the PSD page you can customize the temperature scale via the 'Override default contour interval' option.

[Neven]

Thanks a lot, D S!

Thanks to you guys I only have to look like a fool once (hopefully). ;-)
Next time comparisons will be much better.

And thanks for those links, idunno. As said before, I'm mentally blocking out the methane clathrates, but I'm sure this will be a returning discussion.

[Daniel Bailey]

@ idunno and others so interested:

Over at Skeptical Science we have a post nearing completion on methane hydrate releases. I'll drop a line here when it's done. Maybe another day or so.

For a teaser, it's based largely on:
Shakhove et al 2010
Davy et al 2010
Carozza et al 2011

Keep up your fine work, ladies & gentlemen!

The Yooper

[Neven]

Thanks, Yooper, let us know when it's there.

I've made a new and improved screenshot for filling in the Daily Climate Comparison page. Please, let me know if you see something else that can be improved.

[Gas Glo]

Here are pics for 6 years:

I used 7 weeks from Mar 1 to Apr 19 to try to show longer period not weather. I struggled if I tried to use more than 2 calandar months.

Anomaly
Lat 60-90
long 0-360 All 3 as your screenshot

I used plot size 150 to make it bigger but flikr scales it down so that was a bit pointless.

http://farm6.static.flickr.com/5186/5643443523_3b81c17780_b.jpg

Is that more what was wanted?

[Gas Glo]

Forgot to say an important change:
Interval 1 from -10 to +10 (obviously the longer the period the less range that is needed).

Also NH Polar Stereographic (unchanged from your screenshot).

[Neven]

That's very nice, Gas Glo. I'll try and do it just like that next time. I fiddled a bit with the interval and didn't like it that -10 +10 had white in it (but maybe it would be better visually). Also: which is better, 925mb or 1000mb. I used 925mb a year ago but I can't remember why. As it is pretty counter-intuitive I guess I had a good reason to do it. Of course, 100mb would seem to be the logical choice if you want to know air surface temperatures.

Things are really hot (relatively speaking) on the Siberian coast by the way.

[idunno]

Hi all,

@The Yooper. Good to hear it. I think the first of Hansen's 2011 papers might also be relevent?

Back to temps: it seems that there is now a very large positive SST anomaly on the Eastern side of the North Atlantic, around the British Isles and the Bay of Biscay.

The anomaly in Baffin Bay seems to have slackened slightly.

As I say, I've had my eye a little off the ball, and I am surprised to find that Northern Canada and Greenland are anomalously cold - the opposite of the situation this winter, when I was paying more attention. Did I miss something?

The Guardian has a good piece up about a Greenpeace occupation of a drilling well en route to the Fram Strait, and an analysis of the probable problems resultant from an oil spill in the Arctic.

[Gas Glo]

I don't know why I struggled with longer periods as I now don't have a problem doing Jan 1 to Apr 19. I tried with interval 0.5 from -5 to +7 to reduce the white area - perhaps -7 to +7 would be better to keep the white area as no change from climatology.

http://www.esrl.noaa.gov/psd/tmp/composites/compday.88.104.93.20.111.12.33.52.gif

[Neven]

idunno, maybe you could give your thoughts on this thing in another thread.

Gas Glo, when the white is representing around 0 degrees it looks pretty good, actually (like you have it in your composite collage).

[Gas Glo]

925mb or 1000mb?

I think 925mb is too high for the average height to which heat is radiated from surface and too low for the average height from which heat is radiated to space, but I could be wrong.

We seem likely to think in terms of how much above/below freezing point of water/saline at surface which supports using 1000mb. The only reason I can think of for 925mb is that it might better represent heat content of a thick slab of the atmosphere (perhaps 800-1000mb), but if you want to think of heat content then it may well be more appropriate to look at SST and ignore atmosphere. So I am inclined to say use 1000mb.

[idunno]

Hi all,

Neven, I am sorry about occasionally putting things on the wrong thread. I am not very good with these here computers, and I'm frantically busy looking after some very demanding seedling plants.

I just wanted to note that we are coming up to May, and Jeff Masters is reporting on Weather Underground that Sea Surface Temperatures in the Gulf of Mexico are at near record levels.

Regular readerrs here may remember that an academic called MM Stone published an interesting paper last year that suggested that sea ice area in the Beaufort Sea in September correlates well with the SST in the Carribean in May.

I'm not sure I'm entirely convinced, but it's probably worth noting...

[Neven]

idunno, the seedlings should have priority, but let us know about SST news whenever you have the time.

I didn't know about the Stone paper (or I forgot), but a possible correlation between September SIA in the Beaufort Sea and SST in the Caribbean is very much worth noting.

I should probably read the paper, but how would that work? Does the water flow through the NWP to the Beaufort Sea?

[Neven]

The Catlin Arctic Survey team also has a bit of a teaser on temps and salinity under the ice:

At this stage, it is too early to return detailed observations, and we need to await downloading all the data to laptop when the Explorer Team return to Resolute. However, the readouts for salinity so far indicate that under the sea ice there is a fresher (lower salinity) water layer, resting on top of a steadily increasing salt gradient to at least 100 meters depth.

[idunno]

Hi Neven,

I'm not sure how it works, but Stone seems to have found out something very interesting, which changed my view of the whole situation a lot.

I don't think she actually knows why either, but her finding is that, of 27 possible factors, the one that shows the greater correlation with Beaufort October (Correction, Not September) SIA is Carribean SST. This is also true of Carribean SST one month before, three months before and, the best fit, five months before.

What is most interesting to me is that she also looked at ENSO (El Nino and La Nina, etc) and it does not seem to be related.

I should also say that she is looking at Beaufort only, and I would expect every other area of the Arctic to be equally, or more, affected by this phenomenon.

Which I certainly cannot explain, though I would suggest that it is probably related to the Gulf Stream and to the Atlantic Multidecadal Oscillation.

(Am hoping to get back and pay more attention soon, having exchanged some seedlings for filthy luchre. We have a four day weekend coming up due to the nuptials, etc.)

(On the subject of the nuptials - we also have another scion of the family to auction off to the prettiest bidder shortly. I do wonder if you might consider a Prince Harry's heroic Arctic adventure thread. It might just prove terribly popular. And, just in case any teenage girls have arrived here already, I'd just like to suggest that, in the case of your being introduced, a clear understanding of the ice-flow dynamics of the Fram Strait would possibly deeply impress the young man...)

(Well, you know, we've had the polar bear as the poster boy for ages now. And there are those who would claim that Harry shows some signs of having a higher IQ than the average polar bear. Though this is, obviously, open to dispute.)

I'm off-topic again, innit? I'll get me coat.

[Gas Glo]

>"I'm not sure how it works, but Stone seems to have found out something very interesting"

Hmm. I am not sure. If she had chosen 3 or 4 possible factors then I would trust the test results. She admits to 27 factors which greatly increases the chance of a spurious correlation being found. However from my quick scan it looks as if the 27 factors would have been different if the correlation maps, had looked different. There is some defence against this in considering whether factors have some support in prior literature. Nevertheless if there was a potential pool of hundreds of possible factors the chance of finding something spurious is increased.

If you look at the correlation maps on page 74, for the 5 month lead time there is a similar negative correlation with SST for an area north of Madagascar and I suggest it is hard to see how that could work.

The correlation at 5 months with the Gulf of Mexico is actually midly positive not negative. So the near record temperatures there shouldn't be taken to mean likely low Beauford sea ice concentration.

Stone's thesis seem to place much emphasis on the correlation with Carribean Sea being negative at all lead times of 1 to 5 months. How does that work? Shouldn't the area concerned get closer to the Beauford sea at shorter lead times? So is that a false way of trying to rule out spurious correlations? Actually there is an area of mild positive correlations between the negatively correlated carribean sea area and the route north to Baffin Bay. Of course there could be teleconnection not by water flow but by other means eg water heating air which then sets up atmospheric systems which tend to blow ice from Beauford Sea towards centre of Arctic basis. So Caribbean SST could be positively correlated with central Arctic basin ice concentration.

The study also seems to me to be unaware of how to use multiple predictands. In hurricane forecasts, Koltbach and Grey always point out that

"The best predictors do not necessarily have the best individual correlations with hurricane activity. The best forecast parameters are those that explain the portion of the variance of seasonal hurricane activity that is not associated with the other forecast variables. It is possible for an important hurricane forecast parameter to show little direct relationship to a predictand by itself but to have an important influence when included with a set of 2-3 other predictors."

In summary, maybe I scanned the paper too quickly but it does seem like a bit of a fishing trip for predictands running the risk of spurious finds.

[Kevin McKinney]

Humph.

I'd be more interested in the correlation (if any) between Caribbean SSTs and the month of record tornadic activity in the American Southeast. It's personal: the month began with a very large oak bashing our house to the tune of $85,000 and culminated last night (I sure hope!) with a storm vigil that only ended when thunderstorm activity cut off the satellite signal.

We were lucky, but a lot of people weren't; 132 dead in Alabama, 11 in Georgia, nearly 200 in the region all told, and the toll is likely to rise.

Thoroughly sick of this. . .

[Christoffer Ladstein]

Kevin, you have my deepest symphathy, old oaks are not the best of neighbours! Hopefully you were adequately insured!
(My own "Pippi"-house, 90 year of age, also had a 100 year old fur as a VERY close neighbour, but my very convincing mother in law made the electricity guys chop it down for free a couple years ago, due to "short" distance to high voltage electricity airborne cables!)

Guess the tornado season in the Southern states may be blamed upon the high temps in the Gulf?!

If the temps in the Atlantic are similarily warm, we might "look forward" to a heck of a hurricane season as well....

The Stone theory debated above I find hard to swallow, unless the Gulf stream thus push forward such a great amount of hot water that partially have to cross the Arctic region towards the Beaufort below the seaice...

[idunno]

Hi Kevin,

I'm sorry to hear your personal bad news and I hope that at least you yourself are well. Given that people have clearly died in these storms, my posting above must seem very crass to you, and I apologise.

Good luck!

@Gas Glo - I haven't had time to re-read Stone, but as I understood it, she took 27 separate potential predicants, and rejected 24 as irrelevent - leaving 3 separate potential predicants. Hence no problem with multiple predicants.

The BBC's Richard Black has recently posted something about some current near Madagascar that somebody brighter than me thinks may be related to the Gulf Stream.

In case I haven't repeated it recently, I have absolutely no scientific standing, and very limited scientific understanding, and I quite often post things up here specifically because I don't understand them.

I strongly suspect that it takes a cetacean to understand an ocean, and the last I heard, us hominids were still having translation difficulties...

[Kevin McKinney]

christopher, idunno, thanks.

And, no, I don't think there was anything crass about your comment, idunno. It was just a bad day and I was grumpy, that's all. Should have been more disciplined, especially since it's not really sea ice-related!--not directly, anyway.

But I appreciate Neven's indulgence. Sometimes it helps to vent a bit.

[Neven]

Kevin, you have a free pass to vent anything you like here. I was also sad to read about your oak and house.

[Kevin McKinney]

Thanks, Neven!

[Gas Glo]

Kevin, deepest sympathy. If that cannot cause a bit a grumpyness what would?

Re "I'd be more interested in the correlation (if any) between Caribbean SSTs and the month of record tornadic activity in the American Southeast."

Perhaps
http://www.drroyspencer.com/2011/04/more-tornadoes-from-global-warming-thats-a-joke-right

"Active tornado seasons in the U.S. are almost always due to unusually COOL air persisting over the Midwest and Ohio Valley longer than it normally does as we transition into spring."

[michael sweet]

Personally I wouldn't believe anything roy spencer says. According to this link the weather over the upper midwest was cool the last week but it was warm over the area where the tornadoes were. Did Spencer cite a reference or was he just talking off the top of his head?

It will be interesting to see what the NCDC says around the 15th of the month, they are professionals.

[Kevin McKinney]

"Did Spencer cite a reference or was he just talking off the top of his head?"

It's reasonable; it is usually a 'clash' of cold vs. warm and moist airmasses that creates the unstable atmosphere making for tornado activity. And we had just that set of conditions in the recent outbreak. If you search a bit you can find NOAA people talking about it.

Of course, the other side of the coin applies too--the warmer and moister the Gulf air, the more favorable for tornados as well. Dr. Spencer didn't mention that part--mysteriously.

[Gas Glo]

>"Of course, the other side of the coin applies too--the warmer and moister the Gulf air, the more favorable for tornados as well. Dr. Spencer didn't mention that part--mysteriously."

I probably should have given a slightly longer quote to include the start of the paragraph I quoted which did say
"But contrasting air mass temperatures is the key." or the earlier

"Instead, tornadoes require strong wind shear (wind speed and direction changing rapidly with height in the lower atmosphere), the kind which develops when cold and warm air masses “collide”. Of course, other elements must be present"

So he did mention warm and cool. Does he (mysteriously?) overemphasise the cool? Perhaps a little I am not really sure but I think it is also what he is getting at: If anything, in a globally warmed world the differentials would normally be expected to be lower and hence a lower level of Tornados.

Perhaps secondly just because there is a horrendously bad outbreak of tornados we shouldn't go jumping to conclusions of attributing it to global warming (or whatever else happens to be conveniently anomalous) without a proper attribution process that considers whether outbreaks like this and 74 are getting more common or not and if more common whether that is more likely to be just chance or a physically understood mechanism. Attribution isn't easy but that probably doesn't stop people wanting to blame something.

(Asking if it is correlated with Caribbean SST certainly isn't wrongly attributing it.)

[Bfraser]

@Gas Glo

Actually, he did talk about the warm Carribean:

"An unusually warm Gulf of Mexico of 1 or 2 degrees right now cannot explain the increase in contrast between warm and cold air masses which is key for tornado formation because that slight warmth cannot compete with the 10 to 20 degree below-normal air in the Midwest and Ohio Valley which has not wanted to give way to spring yet. "

(And note that michael sweet above seemed to imply that this might not have been what was going on, though without a discussion of temperatures at various altitudes it can be hard to tell.)

[adelady]

Extracted from Kevin Trenberth's comments "... Tornadoes come from thunderstorms in a wind shear environment. This occurs east of the Rockies more than anywhere else in the world. The wind shear is from southerly (SE, S or SW) flow from the Gulf overlaid by westerlies aloft that have come over the Rockies. ***That wind shear can be converted to rotation.*** The basic driver of thunderstorms is the instability in the atmosphere: warm moist air at low levels with drier air aloft." (My asterisks.)

See full item at http://wonkroom.thinkprogress.org/2011/04/29/tornadoes-irresponsible-denial/