Posted on 04/17/2008 2:03:00 PM PDT by blam
Jet Streams Are Shifting And May Alter Paths Of Storms And Hurricanes
Hurricane Andrew. Storm paths in North America are likely to shift northward as a result of the jet stream changes. Hurricanes, whose development tends to be inhibited by jet streams, may become more powerful and more frequent as the jet streams move away from the sub-tropical zones where hurricanes are born. (Credit: NOAA)
ScienceDaily (Apr. 17, 2008) — The Earth's jet streams, the high-altitude bands of fast winds that strongly influence the paths of storms and other weather systems, are shifting--possibly in response to global warming. Scientists at the Carnegie Institution determined that over a 23-year span from 1979 to 2001 the jet streams in both hemispheres have risen in altitude and shifted toward the poles. The jet stream in the northern hemisphere has also weakened. These changes fit the predictions of global warming models and have implications for the frequency and intensity of future storms, including hurricanes.
Cristina Archer and Ken Caldeira of the Carnegie Institution's Department of Global Ecology tracked changes in the average position and strength of jet streams using records compiled by the European Centre for Medium-Range Weather Forecasts, the National Centers for Environmental Protection, and the National Center for Atmospheric Research. The data included outputs from weather prediction models, conventional observations from weather balloons and surface instruments, and remote observations from satellites.
Jet streams twist and turn in a wide swath that changes from day to day. The poleward shift in their average location discovered by the researchers is small, about 19 kilometers (12 miles) per decade in the northern hemisphere, but if the trend continues the impact could be significant. "The jet streams are the driving factor for weather in half of the globe," says Archer. "So, as you can imagine, changes in the jets have the potential to affect large populations and major climate systems."
Storm paths in North America are likely to shift northward as a result of the jet stream changes. Hurricanes, whose development tends to be inhibited by jet streams, may become more powerful and more frequent as the jet streams move away from the sub-tropical zones where hurricanes are born.
The observed changes are consistent with numerous other signals of global warming found in previous studies, such as the widening of the tropical belt, the cooling of the stratosphere, and the poleward shift of storm tracks. This is the first study to use observation-based datasets to examine trends in all the jet stream parameters, however.
"At this point we can't say for sure that this is the result of global warming, but I think it is," says Caldeira. "I would bet that the trend in the jet streams' positions will continue. It is something I'd put my money on."
The results are published in the April 18 Geophysical Research Letters.
Adapted from materials provided by Carnegie Institution, via EurekAlert!, a service of AAAS.
I think you’re on the right track there. That expresses my thoughts on it rather well.
Well we shall see.. nice meeting you
Hell Yea!
Amen. They can’t have long term data, since the Jet Stream was only discovered in the 1940s, during WWII bombing raids over Germany. They can not have more than 70 years of data, actually much less as far as detailed mapping data. And guess what, the hottest year on record was 1932. Their data doesn’t even go back THAT far. What a bunch of liars.
Good scientist. Find the cause right off the bat. Doesn't have to be an actual cause, but it sounds like science, sort of.
Japan used the jet stream to firebomb Oregon during WW II. I talked to one of those who did this, we worked in the same office in the 60s. Nice guy.
Yup. People of that day were suprised that the Japs knew so much about the jet stream.
The jet stream is the boundary current between two different air masses. The cold air mass is to the north and the warm air mass is to the south. As spring comes along and the temperatures increase (not due to global warming, but due to the Earth going around the Sun), the jet stream mean position moves north.
Another Boo-boo! It wasn’t Rosanne Rosanadanna that said that. Emily Latella did. Nevermind!
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