La Nina caused Drought Persists
Pastor Dale Morgan
La Nina caused Drought Persists*
by Staff Writers
Pasadena CA (SPX) Nov 08, 2007
"After eight very dry years on the Colorado River watershed and a
record-breaking dry winter in Southern California in 2006-2007, the
situation in the American Southwest is dangerously dry," said
oceanographer Bill Patzert of NASA's Jet Propulsion Laboratory,
Pasadena, Calif. "This La Nina could deepen the drought in the already
parched Southwest and Southeast United States."
Patzert and other scientists say La Nina contributed to the conditions
that fueled Southern California's recent deadly wildfires.
A La Nina situation often follows an El Nino episode and is essentially
the opposite of an El Nino condition. During a La Nina, trade winds are
stronger than normal, and the cold water that normally exists along the
coast of South America extends to the central equatorial Pacific. A La
Nina changes global weather patterns and is associated with less
moisture in the air, resulting in less rain along the coasts of North
and South America, the equator and in the far Western Pacific. Jason
will continue to track this change in Pacific climate.
This image of the Pacific Ocean was produced using sea-surface height
measurements taken by Jason. The image is based on the average of 10
days of data centered on October 16, 2007, compared to the long-term
average of observations from 1993 through 2005. In the image, places
where the Pacific sea surface height is higher (warmer) than normal are
yellow and red, and places where the sea surface is lower (cooler) than
normal are blue and purple. Green shows where conditions are near
normal. Sea-surface height is an indicator of the heat content of the
upper ocean.
The comings and goings of El Nino and La Nina are part of a longer
evolving state of global climate, of which sea-surface height is a
useful indicator. The Jason follow-on mission, Ocean Surface Topography
Mission/Jason-2, is scheduled for launch next June and will extend the
data record to a span of two decades.