The
tropical Pacific Ocean remains in the grips of a cool La Niña, as shown by sea-level
heights from mid-October 2007, collected by the U.S-French altimetric satellite,
Jason. This La Niña has slowly strengthened for the past nine months.
Scientists
say La Niña contributed to the conditions that fueled Southern California's
recent deadly wildfires. Further, this climactic condition could worsen the
drought in the southwest and southeast United States.
During a La
Niña, cold water that normally exists along the coast of South America extends
to the central equatorial Pacific. A La Niña 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. A La Niña situation is the opposite of an El Niño condition. (The name
La Niña is from the Spanish for "the little girl," analogous to El
Niño, "the little boy.")
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 near-normal
conditions. Sea-surface height indicates the heat content of the upper ocean.
The program
is named after the Greek mythological hero Jason.
--NASA/JPL Ocean Surface Topography Team and SPACE.com
Staff
Credit: NASA/JPL Ocean Surface
Topography Team
Return each weekday for a new SPACE.com Image of the Day.
| 
