Quick Rise In Temperatures Suggests A Blockbuster El Nino For The Late Nineties; NCAR El Nino Colloquium This Month

BOULDER--El Nino is a warming of the surface waters of the tropical Pacific Ocean whose far-reaching climatic consequences affect societies and economies around the globe. As the second El Nino of the nineties builds in the Pacific, the National Center for Atmospheric Research is hosting a colloquium of experts July 20-August 1 in Boulder. This Tip Sheet has information about the current El Nino, the upcoming colloquium, the relationship between El Nino episodes and global warming, and a recently published book on El Nino for the lay reader. Also included are a list of experts and helpful World Wide Web sites.

The current El Nino

A strong El Nino has developed over the past several months. According to the National Oceanic and Atmospheric Administration (NOAA), waters across the eastern tropical Pacific have warmed to levels of 2 to 3 degrees Celsius above normal. Near the South American coast, waters are the warmest observed since the El Nino of 1982-83. That El Nino, the century's strongest, triggered over $10 billion in weather-related damages worldwide. One signal of the current El Nino's strength: for about 10 days last month, the northeasterly trade winds across the entire equatorial Pacific reverted to westerlies. Such a switch has been observed only once in the past 30 years--again, during the 1982-83 El Nino. If this event behaves as most do, the present oceanic signals of El Nino will continue to intensify during the summer and fall.

The colloquium

A two-week colloquium, "A Systems Approach to El Nino-Southern Oscillation (ENSO): Oceanic, Atmospheric, Societal, Environmental, and Policy Perspectives" will be held in Boulder July 20-August 1. Sponsored by NCAR with additional support from NOAA, the colloquium will update participants on current understanding of the causes, effects, and implications of ENSO and the various roles ENSO plays in the global climate system. By taking a multidisciplinary, systems-based approach, the colloquium seeks to stimulate new insights about climate-society interactions. Prominent ENSO experts will draw from oceanography, atmospheric science, statistics, ecology, and biology, as well as economics and other social sciences, in their presentations.

The colloquium is open to the press by prior arrangement with organizer Michael Glantz (303-497-8119; glantz@ucar.edu). A session schedule is available on the colloquium's interactive Web site, http://www.dir.ucar.edu/esig/enso, or by calling 303-497-8117.

El Nino and global warming

El Nino has been showing up more often since the late 1970s, with a prolonged episode from 1990 to 1995 and another quickly building up now. According to NCAR atmospheric scientist Kevin Trenberth, one possible explanation is that the warm pool in the tropical western Pacific Ocean may be growing larger. Climate models are not yet accurate enough in simulating El Nino to clearly attribute these changes to global warming. However, even without affecting how often El Nino occurs or how long it stays around, global climate warming is likely to intensify the extremes of flooding and drought already experienced in different parts of the world during a normal El Nino and its inverse, La Nina. Trenberth believes that global warming and El Nino reinforce each other in their impact on the environment and society, primarily through their combined effects on the hydrological cycle and the repercussions for water supplies.

The book: Currents of Change

Published in fall 1996 and now in its second printing, Michael Glantz's book, Currents of Change: El Nino's Impact on Climate and Society (Cambridge University Press) is aimed at a broad audience. Glantz defines El Nino, describes its far-reaching impacts on climate and society, and discusses how those impacts might be forecast. The book considers the state of prediction research and the value of forecasts in preparing for widespread effects, from drought to malaria epidemics. An introductory crossword puzzle tests readers' knowledge of El Nino.

ENSO experts

Michael (Mickey) Glantz 303-497-8119 glantz@ucar.eduNCAR/Environmental and Societal Impacts Group (ESIG)Specialty: Interaction between climate anomalies and human activities. A political scientist, Glantz has studied El Nino's societal impacts for 23 years.

Kevin Trenberth 303-497-1318 trenbert@ucar.eduNCAR/Climate and Global Dynamics DivisionSpecialty: Global climate analysis. Trenberth has studied ENSO's interaction with global change and its impact on weather and climate anomalies worldwide, including the Midwest drought of 1988 and floods of 1993.

Gerald Meehl 303-497-1331 meehl@ucar.eduNCAR/Climate and Global Dynamics DivisionSpecialty: Tropical climate and climate change. Meehl has studied El Nino phenomena using observations and global climate models and has analyzed links between El Nino and the Asian-Australian monsoons.

Nick Graham 619-534-1858 ngraham@ucsd.eduScripps Institution of Oceanography/Climate Research DivisionSpecialty: Role of tropical oceans and climate in global climate variability and climate change; seasonal-to-interannual climate prediction; impacts of climate variability and El Nino; marine meteorology of U.S. West Coast.

Ants Leetmaa 301-763-8396, ext. 7553 wd01al@sun1.wwb.noaa.govNational Center for Environmental Prediction/Coupled Modeling ProjectSpecialty: Coupled ocean-atmospheric modeling and seasonal climate prediction, with an emphasis on ENSO.

Martin Hoerling 303-492-1114 mph@cdc.noaa.govNational Oceanic and Atmospheric Administration (NOAA)/Climate Diagnostics CenterSpecialty: The global impact of El Nino on weather and climate.

Antonio Moura 914-365-8493 amoura@iri.ldeo.columbia.eduLamont-Doherty Earth Observatory of Columbia University/International Research Institute for Climate PredictionSpecialty: Climate impacts over South America; applications of seasonal-to-interannual forecasts to agriculture in northeast Brazil and flooding in southern South America. Moura served as director general of Brazil's weather service.

Michael McPhaden 206-526-6783 mcphaden@pmel.noaa.govNOAA/Pacific Marine Environment LaboratorySpecialty: Development of ocean observing systems for climate studies; interpretation of resulting data to understand and predict climate variability.

Pertinent sites on the World Wide Web

Interactive Web Site for ENSO Colloquiumhttp://www.dir.ucar.edu/esig/enso The night before each presentati