Deserts Expanding With Jet Stream Shift

Deserts Expanding With Jet Stream Shift

Thursday, May 25, 2006
WASHINGTON - Deserts in the American Southwest and around the globe are
creeping toward heavily populated areas as the jet streams shift,
researchers reported Thursday.

The result: Areas already stressed by drought may get even drier.

Satellite measurements made from 1979 to 2005 show that the atmosphere
in the subtropical regions both north and south of the equator is
heating up. As the atmosphere warms, it bulges out at the altitudes
where the northern and southern jet streams slip past like swift and
massive rivers of air. That bulging has pushed both jet streams about
70 miles closer to the Earth's poles.

Since the jet streams mark the edge of the tropics, in essence framing
the hot zone that hugs the equator, their outward movement has allowed
the tropics to grow wider by about 140 miles. That means the relatively
drier subtropics move as well, pushing closer to places like Salt Lake
City, where Thomas Reichler, co-author of the new study, teaches
meteorology.

"One of the immediate consequences one can think of is those deserts
and dry areas are moving poleward," said Reichler, of the University of
Utah. Details appear in Thursday's Science Express, the online edition
of the journal Science.

The movement has allowed the subtropics to edge toward populated areas,
including the American Southwest, southern Australia and the
Mediterranean basin. In those places, the lack of precipitation already
is a worry.

Additional creep could move Africa's Sahara Desert farther north,
worsening drought conditions that are already a serious problem on that
continent and bringing drier weather to the countries that ring the
Mediterranean Sea.

"The Mediterranean is one region that models consistently show drying
in the future. That could be very much related to this pattern that we
are seeing in the atmosphere," said Isaac Held, a senior research
scientist with the National Oceanic and Atmospheric Administration. He
was not connected with the research.

A shift in where subtropical dry zones lie could make climate change
locally noticeable for more people, said Karen Rosenlof, a NOAA
research meteorologist also unconnected to the study.

"It is a plausible thing that could be happening, and the people who
are going to see its effects earliest are the ones who live closer to
the tropics, like southern Australia," said Rosenlof. Her own work
suggests the tropics have actually compressed since 2000, after growing
wider over the previous 20 years.

Reichler suspects global warming is the root cause of the shift, but
said he can't be certain. Other possibilities include variability and
destruction of the ozone layer. However, he and his colleagues have
noted similar behavior in climate models that suggest global warming
plays a role.

Moving the jet streams farther from the equator could disrupt storm
patterns, as well as intensify individual storms on the poleward side
of the jet streams, said lead author Qiang Fu, a University of
Washington atmospheric scientist.

In Europe, for example, that shift could mean less snow falling on the
Alps in winter. That would be bad news for skiers, as well as for
farmers and others who rely on rivers fed by snowmelt.

"This definitely favors or enhances the frequency of droughts," Fu said
of such a shift.

It's called climate, you idiot, WarpHole! Climate always changes.

Saul Levy


On 2 Jun 2006 16:00:51 -0700, "Warhol" wrote:

Deserts Expanding With Jet Stream Shift

Thursday, May 25, 2006
WASHINGTON - Deserts in the American Southwest and around the globe are
creeping toward heavily populated areas as the jet streams shift,
researchers reported Thursday.

The result: Areas already stressed by drought may get even drier.

Satellite measurements made from 1979 to 2005 show that the atmosphere
in the subtropical regions both north and south of the equator is
heating up. As the atmosphere warms, it bulges out at the altitudes
where the northern and southern jet streams slip past like swift and
massive rivers of air. That bulging has pushed both jet streams about
70 miles closer to the Earth's poles.

Sure.... climate change...


Saul Levy wrote:
It's called climate, you idiot, WarpHole! Climate always changes.

Saul Levy


On 2 Jun 2006 16:00:51 -0700, "Warhol" wrote:

Deserts Expanding With Jet Stream Shift

Thursday, May 25, 2006
WASHINGTON - Deserts in the American Southwest and around the globe are
creeping toward heavily populated areas as the jet streams shift,
researchers reported Thursday.

The result: Areas already stressed by drought may get even drier.

Satellite measurements made from 1979 to 2005 show that the atmosphere
in the subtropical regions both north and south of the equator is
heating up. As the atmosphere warms, it bulges out at the altitudes
where the northern and southern jet streams slip past like swift and
massive rivers of air. That bulging has pushed both jet streams about
70 miles closer to the Earth's poles.