Biomass burning in the tropics and tropospheric ozone

Ozone in the troposphere is one of the most significant greenhouse gases and the key component which plays the central role in atmospheric photochemistry. However, the spatial and temporal variations of global tropospheric ozone have not been fully understood because of its high variability and difficulty in global observation by satellites. In particular, its variation has not been understood well in the tropics where there are very few ground-based long— term observations. Recently, some observational campaigns focusing on the tropics were conducted, recognizing that the most significant source of tropospheric ozone there is biomass burning. We have been conducting systematic ozone observations in Indonesia for the first time in this region. The result shows that tropospheric ozone increases during the late dry season when forest fires occur. In September and October 1994, widespread forest fires took place in Sumatra and Borneo and we observed remarkable enhancements of tropospheric ozone