An international group of scientists has documented widespread pollution covering about 100 million square kilometers of the tropical Indian Ocean -- roughly the same area as the continental United States. This finding by scientists participating in the Indian Ocean Experiment (INDOEX) raises serious questions about what impact the extensive pollution is having on climate processes and on marine life in the ocean below.
INDOEX, a $25 million project, sponsored in part by the National Science Foundation, is investigating how tiny pollutant particles called aerosols are transported through the atmosphere, and their resulting effect on climate. The project is coordinated by the Center for Clouds, Chemistry and Climate (C4) at the Scripps Institution of Oceanography, a National Science Foundation (NSF) Science and Technology Center at the University of California, San Diego. Paul J. Crutzen, director of the Max Planck Institute for Chemistry and a 1995 Nobel laureate in chemistry and V. Ramanathan, director of C4 at the Scripps Institution of Oceanography, serve as co-chief scientists.
"Aerosols affect the amount of solar radiation that is absorbed and reflected back to space by the atmosphere," explained Jay Fein, program director in NSF's division of atmospheric sciences. "They can also change the composition of clouds, thereby altering the amount of solar radiation they absorb and reflect back to space. Aerosol - cloud - radiation processes are highly complex and not well understood. In fact, the effect of aerosols on our atmosphere's radiation balance is one of the largest sources of uncertainty in predicting future climate. INDOEX was designed to reduce this uncertainty."
Ramanathan said the team of scientists was shocked by the extent of pollution they encountered during the six-week field experiment that began in early February and continued through the end of March 1999.