National Institute for Environmental Studies Equatorial Asia, which includes Indonesia, Malaysia, Papua New Guinea, and surrounding areas, experienced devastating biomass burning in 2015 due to the severe drought condition induced by the extreme El Niño and a positive anomaly of the Indian Ocean dipole. This biomass burning emitted a significant amount of carbon, mainly in the form of carbon dioxide (CO2), into the atmosphere. Equatorial Asia has very few ground-based stations that observe CO2 and other related atmospheric constitutents. Meanwhile, a few satellites could observe atmospheric CO2; however, their observations were less available and subject to errors due to cumulus cloulds typical in the tropics and smokes from the biomass burning.