BOULDER, Colo. -- Will La Nina replace El Nino as the next climate phenomenon in the public eye? It's too early to tell whether this cooling of the eastern tropical Pacific will arrive this winter, but an in-depth discussion of La Nina will hit Boulder this summer.
The National Center for Atmospheric Research will host the world's first summit devoted to El Nino's less-studied counterpart July 15-17. "Review of the Causes and Consequences of Cold Events: A La Nina Summit" is being organized by NCAR senior scientist and El Nino expert Michael Glantz with support from the United Nations University (UNU), based in Tokyo. The summit at NCAR's Mesa Laboratory will draw a number of the nation's top researchers on La Nina and El Nino from universities and government agencies. For a list of participants and a summit agenda, visit NCAR's La Nina Summit Web site at http://www.dir.ucar.edu/esig/lanina. NCAR's primary sponsor is the National Science Foundation.
La Nina is a drop from the normal sea-surface temperatures across the eastern tropical Pacific. Usually, sea-surface readings off South America's west coast range from the 60s to 70s Fahrenheit, while they exceed 80 degrees F in the "warm pool" located in the central and western Pacific. This warm pool expands to cover the tropics during El Nino, but during La Nina, the easterly trade winds strengthen, cold upwelling off Peru and Ecuador intensifies, and sea-surface temperatures there fall as much as 7 degrees F below normal. Like its counterpart, La Nina tends to be strongest during the Northern Hemisphere winter, and it typically lasts one to two years.
Unnamed until the mid-1980s, La Nina (Spanish for "the girl") has received less attention than El Nino. However, La Nina's effects-- such as the 1988 Midwest drought and an increased hurricane threat in the Atlantic Ocean and Gulf of Mexico--can't be ignored.
In the past 20 years there have been only three La Ninas, compared to seven El Ninos. The uneven count has sparked debate over whether global climate change might be tweaking the Pacific tropics toward more El Ninos or even toward a semipermanent warm state.
The goal of the La Nina summit is to identify what is known about La Nina and its societal and environmental impacts. A workshop report will be released afterward. The summit is the first project in a "usable science" collaboration supported by UNU and aimed at helping Pacific Rim countries respond to El Nino and La Nina risks. Glantz is the project coordinator.
NCAR is managed by the University Corporation for Atmospheric Research, a consortium of more than 60 universities offering Ph.D.s in atmospheric and related sciences.
UPDATE: In June, the signals pointing toward a significant La Nina event this fall and winter have strengthened. Monthly long-lead climate forecasts issued by the National Oceanic and Atmospheric Administration (NOAA), which detail some of the expected impacts, can be found on the Web.
for a verbal description of the various forecasts. A more lay-oriented introduction to typical La Nina impacts can be found at the NOAA Pacific Marine Environment Laboratory site "What Is La Nina?"