20 August 2010

Another Perspective on the Russian Heat Wave

[UPDATE 8/25: See this interview of NOAA's Marty Hoerling.]

NOAA has this to say about the Russian heat wave of 2010:
Despite this strong evidence for a warming planet, greenhouse gas forcing fails to explain the 2010 heat wave over western Russia. The natural process of atmospheric blocking, and the climate impacts induced by such blocking, are the principal cause for this heat wave. It is not known whether, or to what exent, greenhouse gas emissions may affect the frequency or intensity of blocking during summer. It is important to note that observations reveal no trend in a daily frequency of July blocking over the period since 1948, nor is there an appreciable trend in the absolute values of upper tropospheric summertime heights over western Russia for the period since 1900.

The indications are that the current blocking event is intrinsic to the natural variability of summer climate in this region, a region which has a climatological vulnerability to blocking and associated heat waves (e.g., 1960, 1972, 1988). A high index value for blocking days is not a necessary condition for high July surface temperature over western Russia---the warm summers of 1981, 1999, 2001, and 2002 did not experience an unusual number of blocking days.

A clear understanding of the causes for the 2010 Russian heat wave is important for informing decision makers and the public on whether they need to transition from a preparedness mode of precautionary responses to an adaptation mode involving investment responses and actions. Our assessment indicates that, owing to the mainly natural cause for this heat wave, it is very unlikely that a similar event will recur next summer or in the immediate future (next decade). Whereas this phenomena has been principally related to a natural extreme event, its impacts may very well forebode the impact that a projected warming of surface temperatures could have by the end of the 21st Century due to greenhouse gas increases.

7 comments:

dagfinn said...

I have a question that did not occur to me until today for some reason. Everybody discusses the heat wave in relation to the fires as if the link between high temperatures and fire was obvious. (As in "widespread fires are stoked by the worst heat wave in Russian memory". Now, I have no expertise in this, but it seems obvious: It's primarily dry conditions rather than heat that are conducive to forest fires. Yes, the two often occur together. But in this case, would it really have made much difference if the region had been slightly cooler (no temperature records, no "1000 year event") but equally dry?

The link between temperature and fires seems indirect at best to me, but as I said I'm no expert.

andrewo said...

Can you ID some of the year(s) that above 50% blocking frequency in the same longitudes as 2010 topped 50%?

If so, can you compare the temperature ranges recorded during those years at those longitudes?

If so, are such comparisons useful? (Why/why not?)

Stan said...

Regardless of whether one agrees or disagrees with this particular release, given the track record of the NOAA, why would anyone care what they wrote?

Fred said...

"Somebody" at NOAA is in deep doo-doo.

When the tall forehead types running the organization, some would say into the ground, find out that "somebody" wrote a reasoned, scientifically sound analysis of the Russian summer of 2010 Heat Wave, they will be very upset at "somebody" for going so far off the "ACK Global Warming did it" message that NOAA has so carefully constructed and leveraged into huge funding increases.

Harrywr2 said...

dagfinn said... 1

"The link between temperature and fires seems indirect at best to me, but as I said I'm no expert."

Alternatively, you could do as the Russians did, drain your peat bogs...and wait for the inevitable spontaneous combustion to occur...

http://www.wetlands.org/NewsandEvents/NewsPressreleases/tabid/60/articleType/ArticleView/articleId/2357/Russias-fires-worsened-by-peatland-drainage.aspx

Howard said...

-4- Fred
I think NOAA *did* try to keep on-message, with the statement: [I]ts impacts may very well forebode the impact that a projected warming of surface temperatures could have by the end of the 21st Century due to greenhouse gas increases.

Despite the weasel-wording ("may very well forebode"), this is clearly an intimation that warmer temperatures will engender these conditions more frequently. This association is not based on fact: observations reveal no trend in a daily frequency of July blocking over the period since 1948. Further, NOAA state: It is not known whether, or to what exent, greenhouse gas emissions may affect the frequency or intensity of blocking, so there doesn't even appear to be a theoretical reason to tie this kind of event to warming.

And on a less contentious note, can someone please inform NOAA that "phenomenon" is the singular. I can't be the only person who objects to "this phenomena has been ..." Have they no editors?

Dean said...

Weather Channel Senior meteorologist Sto Ostro has analysed 500 MB pressure heights that he says could be connected with AGW and how that can magnify some extreme weather events. The NOAA report in your link includes that the 500 MB height is one of the greatest such anomalies of this type ever seen. So there is a hypothesis that connects the heat wave to AGW - certainly not proof at this point, but something that should and I expect will be looked into. Ostro mentioned on his blog that he is in the process of preparing a peer review paper on his hypothesis. He also gave me the following link to a published paper that deals with a similar issue:

http://stephenschneider.stanford.edu/Publications/PDF_Papers/santertext.pdf

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