Figure 1: January-March mean surface temperature anomaly
While we know that a short-term variation doesn’t make a long-term trend it is interesting, in view of the bitterly cold winter in some parts, that the global mean the surface temperatures have been around record highs. Climate Progress has the story:
It was the hottest March in both satellite records (UAH and RSS), and tied for the hottest March on record in the NASA dataset. It was the hottest (or tied for hottest) January through March in all three records.
The image above is from NASA. March was an equal record high (bottom right). Also notable was the marked band of cooling across the USA, Europe and Asia. For months now we have been getting stories like this.
Back in January we noted that the extraordinary cooling in the mid latitudes in the Northern Hemisphere was due to a cold air outbreak from the Arctic. Now new studies have suggested that in Northern Europe at least the sun may be the culprit. A compelling link has been found between low solar activity and winter temperatures in Northern Europe.
The suspicion is that the sun induces changes in the stratosphere, which in turn affects the weather in the troposphere, producing a kink in the jet stream which blocks the warm westerlies from the gulf stream, replacing them with an icy blast from Siberia. This diagram shows how it might work:
Figure 2: Kinky jet stream
The statistical correlation going back to the seventeenth century between solar activity and low temperatures in Northern Europe is said to be very robust. Yet to me there needs to be an explanation why the intense cold seems to have started elsewhere. Have a look at the temperature anomaly map for December:
Figure 3: Global map of December 2009 temperature anomaly
You will recall that by February it was embarrassingly warm in Vancouver, while Washington and New York were freezing. The shape of the cold band is similar in both images and extends way beyond Europe, to which the anomalous cold was said to be limited in the study.
Which brings me to another study by Susan Solomon et al about the contribution of lower stratospheric water vapor to decadal changes in the rate of global warming. The story goes like this.
Since 2000 there has been a reduction by about 10% of water vapour in the lower stratosphere, which means that less long-wave out-going radiation is trapped. The study calculates that this effect has reduced global warming by about 25% from what it would have been. Conversely water vapour increased in the lower stratosphere from 1980 to 2000, which is thought to have been responsible for 30% of the warming in the 1990s.
The question now is, what caused the changes in water vapour? One possible source is the decay of methane, which converts to CO2 and H2O. This is thought not to be the cause, because methane emissions were fairly stable over the period.
The other possible cause would be from convection through the tropopause, the layer separating the troposphere and the stratosphere. According to Gavin Schmidt at RealClimate suspects include changes in the El Nino/La Nina patterns, changes in Asian aerosols, or in solar-driven ozone. We don’t know.
There are further reports on the study at NOAA, at Skeptical Science (with some useful images), and in the Scientific American.
The NPR treatment explains that the drying effect is unlikely to last:
Andrew Dessler at Texas A&M University says this is almost certainly a temporary state of affairs.
“This can’t keep cooling or offsetting carbon dioxide forever,” he says. For one thing, the stratosphere can get only so dry. For another, the weather patterns that caused the stratosphere to dry out are bound to change.
So the chances are that the warming trend will not long be inhibited from this source.
Climate Progress is quick to point out that most of the extra heat involved in global warming (about 90%) ends up in the ocean. Here a conundrum has been uncovered with an article by Kevin Trenberth and John Fasullo. The original reference is here with a PDF here. Trenberth and Fasullo point out that if you compare satellite measurements of heat radiation balance at the top of the atmosphere with ocean heat content, then about half the additional heat is missing from 2005. One problem is that the Argo program which began only in 2000 does not measure the ocean below 2000 metres. The average depth of the ocean is 3600 metres.
So the question is whether the satellite measurements or the ocean measurements are wrong or are not being interpreted properly, or whether the missing heat is in the deep ocean.
Sceptical blogs are already onto this one. Roger Pielke Snr suggests that the satellite measurements are probably wrong and the heat just isn’t there.
Skeptical Science has just posted on the topic.
RealClimate would also be a candidate to comment.
Skeptical Climate has also just done a post looking at whether the ocean is cooling. The verdict is that you definitely can’t say the ocean is cooling, but:
Independent analysis seem to indicate that over last half dozen years, the ocean has shown less warming than the long term trend but nevertheless, a statistically significant warming trend.
We await further developments.
Getting back to the northern winter this year, there has been another change which might encourage AGW sceptics/deniers. The Arctic ice (go here for daily updates) has covered a larger area than usual in recent years.
Figure 4: Arctic sea ice extent time series
If you check out the National Snow and Ice Data Center site, you’ll find this explanation:
The maximum Arctic sea ice extent may occur as early as mid-February to as late as the last week of March. As sea ice extent approaches the seasonal maximum, extent can vary quite a bit from day to day because the thin, new ice at the edge of the pack is sensitive to local wind and temperature patterns. This March, low atmospheric pressure systems persisted over the Gulf of Alaska and north of Scandinavia. These pressure patterns led to unusually cold conditions and persistent northerly winds in the Bering and Barents Seas, which pushed the ice edge southward in these two regions.
Also the unusual wind direction means that less ice than usual was blown out into the North Atlantic.
Skeptical Science has a detailed guest post by Peter Hogarth on recent trends on Arctic ice. The important point, I think, is that thinning has proceeded apace in 2008 and 2009. In comments a link is given to an Arctic Ice Volume Anomaly measure which tells the story:
Figure 5: Arctic sea ice volume
So global warming hasn’t been cancelled. Locally your experience of the last few months will vary considerably according to where you live:
Figure 6: Australian maximum temperature anomaly January-March 2010
Better Brisbane than Perth, although if you check the actual against the averages I make it plus 1.13C, so there should be a little yellow patch over our fair town.
Hasn’t felt that way. I must be adapting.
Just saw the weatherman on Sunrise Today referring to this very report with a pro-warming message. Colour me shocked.
Well there is certainly something going on. Your usual thoroughly interesting production. I would like to see a lot more visualisations of the air flow systems top to bottom coming from NASA or the met offices. Or at least what they believe to be going on. By far the best surface level visualisation is the SBS weather globe, albeit far too brief. That visualisation patched together for a whole year would be absolutely fascinating. We need to be seeing the full sectioned circulation surface to stratosphere.
Oh, please.
The Reuters report states breathlessly that “[t]he National Oceanic and Atmospheric Administration reported on Thursday the world’s combined land and ocean surface temperatures in March were the hottest on record.”
Oh really? Would that be the same March where NOAA claimed that the polar regions were on fire, yet satellite footage shows that polar sea ice reached at or near its 1970-2001 average in March – thus meaning that the claims of record high temperatures in the polar regions are ludicrous? (Of course, Drudge Report ratehr snarkily links to Vostok, Antarctica, where the temperature, less wind chill, is a balmy minus 103 degrees farenheit. With wind chill taking it to -143F…)
And do take a look at the March map from NASA-GISS – showing the polar regions on fire in blazing, emotive reds and numerous hot spots around the globe.
http://4.bp.blogspot.com/_kMs_q1g_CmQ/S8s3u_nbVnI/AAAAAAAAE88/XjYUyecvHrY/s1600/Iceland+hotspot.gif http://4.bp.blogspot.com/_kMs_q1g_CmQ/S8s3u_nbVnI/AAAAAAAAE88/XjYUyecvHrY/s1600/Iceland+hotspot.gif
On the above map, take a careful look at Iceland – shown in red as described and as “experiencing an extremely hot March”. Climate Audit dug through the figures and found:
So NASA is misreporting the temperature at that station in Iceland by 11.8 degrees C.
That is not a mistake.
That is fraud.
Check the real data. Do not believe spin-doctors and AGW marketers. It is now within your ability to do so.
We have known for some time that the surface data temperature being propounded by the major players in the AGW field are untrustworthy in the extreme, and that the station data sets have been tampered with. Yes, it is tampering whan ALL of the data sets show ‘adjustments’ only in the positive, with no justifications for those ‘adjustments’.
MarkL
Canberra
You’re comparing the actual from Brisbane City against the averages from Brisbane Airport, which is a bit cooler in summer, being closer to the ocean. Of the longer-term sites in the area Amberley was 0.3 above normal, Brisbane Airport 0.1 below and Cape Moreton 1.2 above.
No-one looking at these maps will be surprised to learn that Canada had their warmest winter on record. Haven’t seen March rankings from there yet.
Oops, Blair, thanks for that. As to my adapting, I do think that the summers in recent years have been a little less humid than they used to be.
BilB, a top to bottom visualisation would be interesting, but the decadal variations are the real intrigue.
To complete the picture you need an ocean circulation model. My understanding of what happens at depth is very limited.
I’d like to thank John D for sending me a couple of links which I might have missed and which were very timely. They caused me to write the post in a very different way. It ended up being material for at least three posts, but I thought there was value in wrapping all the topics together.
MarkL @ 3, we don’t like to get involved in Climate Audit’s obsessions on this blog. Yes, it looks bad, but if there is a problem I’m sure it will be sorted out between the Finnish Meteorological Institute and NASA GISS. No doubt they’ll be conscious that their emails might appear on the front page of the newspapers.
As a non-scientist I’d make these observations.
Finland covers 338,424 square kilometers. That’s about one 1500th of the earth’s surface or 0.067%. A stuff-up on Finland is not going to alter the overall result.
I don’t know how the map you linked to is generated, but the three month map (top left of Figure 1 in the post) colours Finland blue.
If you were going to indulge in fraud why would you insert hot spots that make little difference and which stick out like the proverbial dog’s appendages? It would be a case of Dumb and Dumber.
On the Arctic sea ice, you obviously didn’t read the post. The volume decline is ultimately more significant than the surface area. Much of the ice has been described as “rotten”. It’s not in good shape.
Brian, two things.
Firstly, interesting just how long a post which did not concur with your assessments stayed in moderation – and hence invisible.
Secondly, the term ‘rotten ice’ has no actual meaning in ice navigation (yes, I have been in ice waters). First year ice is not ‘rotten’. It’s just first year ice. You may not know that first year ice can be thicker than older ice. It merely depends on how much is has been compressed into icefields by wind and current. Newer ice, being thinner, concertinas over itself into icefields quite easily. Older, thicker floes tend not to do this.
So I did read your post: I just know it to be incompletely factual.
Finally, are you actually aware of the systematic corruption of the data in land-side data records?
MarkL
Canberra
The reason is not interesting at all, MarkL, so boring in fact that I’m not going to spend any time on it. However, my usual practice when a comment is released upthread is to make a comment drawing attention to it, which I did. My memory is that it slid down the sidebar fairly rapidly, something I obviously can’t control.
I didn’t make the “rotten” comment up. I think what I saw was a derivative of this news release.
Here’s another report which includes this comment:
We’ll just have to wait and see how it all works out. I tend to think that the volume decline is of most significance, but I’ve always understood the volume of the Arctic sheet was not well measured.
Furthermore. Watts Up With That? reckoned the winter sea ice, as in Figure 4, was approaching “normal”. The 1979-200 average already incorporates a fair bit of decline if you compare it with 50 years earlier.
On temperature data, I’m aware that measurements are systematically normalised. If something happened in Finland that went beyond that I’m sure it will get sorted.
The monthly map from the U.S. National Climatic Data Center shows below-normal temperatures in the far north of Finland and a blank over the rest of the country, which suggests something went wrong with the Finnish reports and NCDC’s quality control procedures picked it up. NCDC had March as the warmest on record too.
Believe it or not, some of us take climate data quality control pretty seriously. I should know – I spent a fair bit of a public holiday Monday yesterday trawling 100 years of historical data from Thargomindah and Tibooburra for possible errors.
Blair, I know how hard you guys work, and do the best you can in a difficult area. This was explained in some detail by you and Roger Jones on another thread. We shouldn’t need to go over all that territory again.
It’s disappointing when people still grab a bit of data and make allegations of fraud.