BOULDER--How much do sulfate aerosols--a form of pollution--cool the climate? That's one of the most pressing questions for understanding global climate change. To help find the answer, the National Center for Atmospheric Research (NCAR) has sent researchers, instruments, and a C- 130 research aircraft owned by the National Science Foundation (NSF) to the $25-million Indian Ocean Experiment (INDOEX). NSF is NCAR's primary sponsor and a partial sponsor of INDOEX.
INDOEX is based in the Republic of the Maldives, an archipelago southwest of India's southern tip. There, NCAR scientists are working alongside more than 70 researchers from a dozen nations to observe the tropical oceans and atmosphere from January to April. The University Corporation for Atmospheric Research, NCAR's parent organization, is overseeing operations from its support office for logistics and data management, headed by Richard Dirks of the UCAR Office of Programs. The highly instrumented C-130 aircraft will be based through March 27 at Male' airport, which occupies its own island in the archipelago.
According to NCAR's Jeffrey Kiehl, a principal investigator for INDOEX, "In the future, pollution in the tropics will increase, so we'd better understand it now. The chemistry in the tropics is severely undersampled." The Indian subcontinent and surrounding nations are rich sources for many kinds of aerosols, including those produced from industrial and auto emissions, biomass burning, and soil dust. With Asia's population rising at a dramatic rate, the amount of sulfur dioxide released into the atmosphere is expected to increase. Sulfur dioxide is converted into sulfate aerosol in the atmosphere.
The ability of sulfate aerosols to reflect the sun's radiation may be
one reason that increasing greenhouse gases have not warmed the earth as
much as some climate models have predicted. Sulfates also contribute to
National Center for Atmospheric Research/University Corporation for Atmospheric Research