Satellite investigations of fire, smoke, and carbon monoxide during April 1994 MAPS mission: Case studies over tropical Asia

During April 9-19, 1994, the Measurement of Air Pollution from Satellites (MAPS) measured free tropospheric carbon monoxide (CO) concentrations on a near-global basis. For these eleven days the global 1 km advanced very high resolution radiometer (AVHRR) Pathfinder data are used to detect fires and smoke over the Indo-Burma region (85 degrees E-110 degrees E; 10 degrees N-30 degrees N). The fire activities are categorized for four major ecosystems that include (1) cropland/natural vegetation mosaic (CNVM), (2) evergreen broadleaf forest (EBF), (3) mixed forest (MFD), and (4) grassland (GL). Using published emission rates between particulate matter and carbon monoxide concentrations from temperate areas, the fire counts along with other information are used to obtain estimates of CO concentrations from the AVHRR data. More than 7000 fires are detected during the study period with 23%, 43%, 24%, and 10% fires in the CNVM, EBF, MFD, and GL ecosystems, respectively. The enhanced CO concentrations over the area of study are either over or downwind of the fires detected by the AVHRR. The preliminary AVHRR estimates of CO concentrations are smaller than the MAPS-measured values by a factor of 4 to 5 for fire counts greater than 200. The differences are attributed to the lack of transport mechanisms and other assumptions in the current model. However, these results show a good potential for using the AVHRR measurements to detect fires and smoke and also to estimate CO concentrations.