Wildfires and agricultural fires are widespread in the southeast Asian countries of Thailand, Laos, and Cambodia from February to April each year, and have been responsible for severe deforestation in the region. The impact of these intense local pollution sources on regional air quality can be monitored from space using satellite remote sensing. This false-color image shows carbon monoxide plumes at an altitude of roughly 3 km (700 millibars) in the atmosphere over southeast Asia. This image represents a composite of data collected from February 20-25, 2003, by the Measurements Of Pollution In The Troposphere (MOPITT) instrument aboard NASA’s Terra satellite. The gray areas show where no data were collected, either due to
persistent cloud cover or gaps between viewing swaths. Carbon monoxide is a good tracer of pollution since it is produced as a by-product of the combustion associated with biomass burning. The regions of high carbon monoxide correlate well with earlier observations of the source fires made by the Moderate Resolution Imaging Spectroradiometer (MODIS).