Large amounts of air pollution within a short period of time can be caused by burning agricultural waste or forest wild fires. Depending on the weather conditions, these biomass burning air pollutants have significant impacts not only on local but also on regional air quality, biogeochemical cycles, climate, and the hydrological cycle. Southeast Asia in springtime is a region with significant aerosols and air pollutants caused by biomass burning. A team of scientists, including U.S. Department of Energy researchers at Pacific Northwest National Laboratory, analyzed the seasonal variations of the pollutants carbon monoxide, ozone, and particulate matter during the Southeast Asian spring months. The team found that higher concentrations over Taiwan during springtime are related to biomass-burning plumes transported from the Indochinese peninsula of Southeast Asia. They identified the spatial distribution of high aerosol optical depth (AOD) by satellite measurements and the Aerosol Robotic Network (AERONET) ground observations, and found it could be reasonably captured by the Weather Research and Forecasting with Chemistry (WRF-Chem) model. According to the simulations, 34% of the AOD was attributed to organic carbon over Indochina, 4% from black carbon. The research suggests that a significant reduction in radiation attributed to biomass-burning aerosol particles and their impact on the regional climate in East Asia merits attention.