America's Jet Stream Creeping North

[Guest guest]

http://dsc.discovery.com/news/2008/04/18/jet-stream-storm.html?

dcitc=w01-101-ae-0001

America's Jet Stream Creeping North

Seth Borenstein, Associated Press

April 18, 2008 -- The jet stream -- America's stormy weather maker --

is creeping northward and weakening, new research shows. That

potentially means less rain in the already dry South and Southwest

and more storms in the North.

And it could also translate into more and stronger hurricanes, since

the jet stream suppresses their formation. The study's authors said

they have to do more research to pinpoint specific consequences.

From 1979 to 2001, the Northern Hemisphere's jet stream moved

northward on average at a rate of about 1.25 miles a year, according

to the paper published Friday in the journal Geophysical Research

Letters. The authors suspect global warming is the cause, but have

yet to prove it.

The jet stream is a high-speed, constantly shifting river of air

about 30,000 feet above the ground that guides storm systems and cool

air around the globe. And when it moves away from a region, high

pressure and clear skies predominate.

Two other jet streams in the Southern Hemisphere are also shifting

poleward, the study found.

The northern jet stream " is the dominant thing that creates weather

systems for the United States, " said study co-author Ken Caldeira, a

climate scientist at the Carnegie Institution of Washington in

Stanford, Calif. " Bascially look south of where you are and that's

probably a good guess of what your weather may be like in a few

decades. "

The study looked at the average location of the constantly moving jet

stream and found that when looked at over decades, it has shifted

northward. The study's authors and other scientists suggest that the

widening of the Earth's tropical belt -- a development documented

last year -- is pushing the three jet streams toward the poles.

Climate models have long predicted that with global warming, the

world's jet streams would move that way, so it makes sense to think

that's what happening, Caldeira said. However, proving it is a

rigorous process, using complex computer models to factor in all

sorts of possibilities. That has not been done yet.

A rate of 1.25 miles a year " doesn't sound like much, but that works

out to about 18 feet per day, " Caldeira said. " If you think about

climate zones shifting northward at this rate, you can imagine

squirrels keeping up. But what are oak trees going to do?

" We are seeing a general northward shift of all sorts of phenomena in

the Northern Hemisphere occurring at rates that are faster than what

ecosystems can keep up with, " he said.

Dian Seidel, a research meteorologist for the National Oceanic and

Atmospheric Administration who wrote a study about the widening

tropical belt last year, said she was surprised that Caldeira found

such a small shift. Her study documented that the tropical belt was

bulging at a much faster rate. Caldeira said his figures represent

the minimum amount of movement.

The jet stream also factors into bumpy air travel. It is a cause of

clear air turbulence that airline pilots try to avoid by tracking

where the jet stream is.

[Guest guest]

Unfortunately the weather in the Bay Area is a good indicator. I've seen

too much consistent change in the weather pattern. I just hope that the jet

stream " changes it's mind " soon! ;-) I hate dry weather as we've been

having an unusual amount of.

Randy Garrett

Antioch, CA USA

-----<---{(@

America's Jet Stream Creeping North

http://dsc.discovery.com/news/2008/04/18/jet-stream-storm.html?

dcitc=w01-101-ae-0001

America's Jet Stream Creeping North

Seth Borenstein, Associated Press

April 18, 2008 -- The jet stream -- America's stormy weather maker --

is creeping northward and weakening, new research shows. That

potentially means less rain in the already dry South and Southwest

and more storms in the North.

And it could also translate into more and stronger hurricanes, since

the jet stream suppresses their formation. The study's authors said

they have to do more research to pinpoint specific consequences.

<snip>

No virus found in this outgoing message.

Checked by AVG.

Version: 7.5.524 / Virus Database: 269.23.2/1388 - Release Date: 4/20/2008

3:01 PM

[Guest guest]

It probably is. That's a concern for me because more hurricanes means more threat to my place in Alabama. At least i don't own any beach front property.

In a message dated 4/20/2008 6:42:24 P.M. Eastern Daylight Time, no_reply writes:

America's Jet Stream Creeping NorthSeth Borenstein, Associated PressNeed a new ride? Check out the largest site for U.S. used car listings at AOL Autos.