From the GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre and the Varved D2O department:
The water cycle amplifies abrupt climate change
The role of the hydrological cycle during abrupt temperature changes is of prime importance for the actual impact of climate change on the continents. In a new study published in Nature Geoscience online (January 19, 2014) scientists from the University of Potsdam, Germany and the GFZ German Research Centre for Geosciences show that during the abrupt cooling at the onset of the so-called Younger Dryas period 12680 years ago changes in the water cycle were the main drivers of widespread environmental change in western Europe.
The team of scientists analyzed organic remains extracted from Meerfelder maar lake sediments from the Eifel region, western Germany, to reconstruct changes in precipitation patterns in unprecedented detail. They were able to show that the intrusion of dry polar air into western Europe lead to the collapse of local ecosystems and resulted in the observed widespread environmental changes at that time.
Organic remains of plants from lake sediments as molecular rain gauges
The exact sequence of events during abrupt climate changes occurring over only a few years is one of the great unknowns in paleoclimate research. The new results presented here were obtained by using a novel method, where molecular organic remains derived from plant fossils were extracted from precisely dated annually laminated lake sediments. The ratio of the heavy Deuterium to the light Hydrogen isotopes in these biomarkers can be used to reconstruct changes in precipitation regime and moisture sources with unprecedented detail.
The Younger Dryas period was the last major cold period at the end of the last glaciation with a duration of about 1100 years, when an abrupt change in the pathway of westerly wind systems over Europe lead to massive environmental change within a few years, as GFZ scientists showed in an earlier study. Dirk Sachse, the head of the workgroup at the Institute of Earth and Environmental Sciences of the Potsdam University explains: “In our new study we can show for the first time that this change in the pathway of westerly wind systems brought dry polar air into western Europe and this was the ultimate cause for the widespread disappearance of forests in the area.”
Changing westerly wind pathways bring dry polar air into western Europe
With these new results, the group also supports the hypothesis that this change in atmospheric circulation patterns over western Europe took place 170 years after the onset of cooling, as observed in the Greenland Icecores. The authors attribute this delay to the subsequent southward expansion of sea ice in the North Atlantic following the onset of cooling. This lead to a southward shift of the polar front channeling dry polar air into western Europe. “Our results also show that abrupt climate and environmental change may not be coeval on large regional scales, but can take place with substantial regional and temporal delays” explains Prof. Achim Brauer from the GFZ German Research Centre for the Geosciences.
The results of this study, which was funded by the German Research Foundation (DFG) through its Emmy-Noether Programme and the Helmholtz Climate Initiative REKLIM, do not only show unequivocally that temperature changes can have regionally different impacts, but also that the water cycle acts as amplifier of change with potentially severe effects on continental ecosystems. As such, the regional impacts of future climate changes can be largely driven by hydrological changes, not only in the monsoonal areas of the world, but also in temperate areas, such as western Europe. The results of this study contribute to the development of higher spatially resolved regional climate models, which will allow for a better prediction of the regional impacts of future climate change.
contact: Dr. Dirk Sachse, E-mail: dirk.sachse(at)geo.uni-potsdam.de
Prof. Dr. Achim Brauer, E-mail: brau(at)gfz-potsdam.de
Internet: http://dx.doi.org/10.1038/ngeo2053
Rach, Oliver; Brauer, Achim; Wilkes, Heinz; Sachse, Dirk (2014): “Delayed Hydrological Response to Greenland Cooling at the onset of the Younger Dryas in Western Europe”, Nature Geoscience, Advance Online Publication, Jan. 19, 2014; doi:10.1038/ngeo2053
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What bearing does this have on Michael Mann’s Bristlecone Pines hockey schtick graph.
A bit OT, but in my area on TV yesterday they aired “The Day After Tomorrow”. (If you’re not familiar with the movie, the northern hemisphere suffers a bunch of sort of “Super Cyclonic Polar Vortexes” caused by, well, you’ll have see the movie or watch The Weather Channel to find out.) I hadn’t noticed it being scheduled here for awhile now. Is it starting to pop up in other lineups?
That would be interesting to know, Gunga Din (re: 2:22pm). It would help track who the main propagandists are.
The great thing about that movie is, like “The Blob,” (1957?), it is so blatantly fiction that it doesn’t do anything to promote AGW. Like the Scary House at the carnival. We loved being scared by that ride, but, out in the cold light (and brrrr, folks that global warmin’ — it’s COLD, heh) of day, did we think what we saw was real? “Aaa, go sit on a snow cone, Tommy, you’re full of beans. (laughing)”
Gunga Din says:
January 21, 2014 at 2:22 pm
A bit OT, but in my area on TV yesterday they aired “The Day After Tomorrow”.
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Janice and Gunga Din… I feel the need to comment here. That movie had things so upside down scientifically and politically – that if I recall correctly, Mexico saves the US, which was covered in glaciers or something like that. The movie rates right up there with An Inconvenient Truth.
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Sure the movie was all messed up. But why was it made? To plant an idea? It’s cold because it’s warm? It was science fiction so nothing had to proved. (But did give a Al Gore a great shot of a calving glacier made out of styrofoam. 😎
Did you ever see Star Trek the Next Generation episode 161, “Force of Nature”? (The working title was originally called “Limits”.) It was from the last season. The basic story was that warp drive was tearing the fabric of space so had to be limited.
Jeri Taylor (one of the big wigs) said, “It was a wonderful environmental premise that something we take for granted is doing damage to the space around us. It was the metaphor which most closely evoked our present situation.” (In 1993 that would be the ozone hole.) “At the beginning of the seventh year, I sent Naran” (Shankar, who wrote the episode) “and Brannon to a big breakfast meeting of an environmental watchdog group that we have here in Hollywood and they came back inspired. Naren was so galvanized. he said, ‘I want to take a crack at “Limits”. I want to do this. This is important.’ I agreed. It was a story I really wanted to do and i think it does make an important statement.”
(The quote is from “Captains’ Logs: The Unauthorized Complete Trek Voyages.”)
Last night I typed all that from the book. Today I came across this. It has all that I quoted plus a bit more about the episode itself.
http://en.memory-alpha.org/wiki/Force_of_Nature_%28episode%29
(Scroll down to the Background Information)
Wow Gunga Din: You certainly have a good memory. But as usual, you post with integrity.
I never got into Star Trek AFTER the original series. I loved them… and by the time the Next Generation came, it was, to me, too much like a soap. I show my age now right? But most Trekies say it was better. Perhaps I was getting to the age where I was too busy to watch much TV then. PS – I agree with your thoughts and connections regarding The Day After Tomorrow. Terrible movie that become more fodder for the AGW believers.