Washington, D.C., May 9, (AP by Randolph E. Schmid)--La Nina, the Pacific Ocean cooling that has brought disruptive weather for months, including last summer's drought, may finally be easing.
La Nina has disappeared in the eastern Pacific Ocean and is rapidly easing over the rest of that ocean, according to researchers at NASA's Goddard Space Flight Center in Greenbelt, Md., who studied satellite and ocean buoy observations.
``As expected, La Nina reached a maximum in January 2000 and has been waning ever since,'' said oceanographer David Adamec.
Nevertheless, climate experts at the National Weather Service say La Nina ``is not quite history yet.''
Jim Laver, deputy director of the Weather Service's Climate Prediction Center in Camp Springs, Md., said that while ocean temperatures have moderated in the eastern pacific, they remain cool in the central portion of the ocean.
``We would say (La Nina) is still there, but it's declining,'' he said. ``We think by the end of the year it will be neutral.''
Unusually cold surface water, which is a prime characteristic of La Nina, is being replaced by water 4 degrees Fahrenheit warmer off the coast of South America, Adamec said.
La Nina is the latest in a series of unusual Pacific Ocean events that have been affecting climate around the world for three years.
When the water in that ocean is unusually warm it causes more evaporation, creating more storms, disrupting the upper level jet stream and reducing the fish catch off South America. That's called El Nino, the Spanish term for the little boy, referring to the Baby Jesus, because it traditionally has been first noticed by fishermen around Christmas time.
When scientists determined that El Ninos, which occur every three to seven years, were sometimes followed by periods of unusually cold water, they decided to name them La Nina, or little girl.
In the spring of 1997 an unusually warm El Nino developed, changing storm tracks across the Pacific and causing storm after storm to slam into the West Coast of the United States. At the same time, the effects of this event tended to suppress hurricanes in the Atlantic. It developed into the strongest El Nino on record.
In 1998 the situation reversed. Instead of water conditions returning to normal, cold water replaced the warm bringing on La Nina, which also causes unusual weather in other areas, such as droughts in the central and eastern United States.
If La Nina does come to an end, it could be good news for residents of the East and Gulf Coasts _ eventually.
La Nina years tend to have more than the usual number of hurricanes in the Atlantic Ocean. Last year was marked by 12 tropical storms, including five major ones.
Laver cautioned against too much optimism for the upcoming hurricane season, however, noting that the vestiges of La Nina are still there and are likely to influence this year's storm season.
Copyright (c) 2000 The Associated Press