Role of Local Air‐Sea Interaction in Fire Activity Over Equatorial Asia.

Fire activity in Equatorial Asia shows large interannual variability. Teleconnections by El Niño‐Southern Oscillation and Indian Ocean Dipole are linked to drought and fire events; however, we found here that significant role of local Sea Surface Temperature (SST) over the Banda Sea in interannual variability of Equatorial Asian burned area in October even after removing the linear effects of teleconnections. October is the transient period from dry to wet season and strengthened seasonal circulation in October leads to a negative SST anomaly through Wind‐Evaporation‐SST mechanism. This anomalous local air‐sea interaction sustains the dry season into October and stronger fire activity. Moreover, we found that the sensitivity of precipitation to SST is higher in October than in other months, hence fires in Equatorial Asia can be sensitively driven by local SST changes. Identification of this sensitivity will underpin better predictions of fire activity and air quality in Equatorial Asia. Plain Language Summary: Previous studies have emphasized that the remote forcing associated with El Niño‐Southern Oscillation and Indian Ocean Dipole are the most important climate factors in controlling fire activity in Equatorial Asia. However, we found here that there is a huge diversity of fire activity among El Niño events. In this paper, we newly found that the local air‐sea interaction significantly influences on fire activity in Equatorial Asia. When the seasonal wind gets stronger, the Banda Sea, local sea located between Kalimantan and New Guinea, is cooler and it leads to the drought and strong fire activity. We also found that the role of local air‐sea interaction strongly depends on the seasonality, which is related to seasonal variation of sea surface temperature climatology. Our findings will be utilized for better predictions of fire activity and air quality in Equatorial Asia. Key Points: Strong diversity of fire activity in Equatorial Asia among El Niño eventsImportance of local air‐sea interaction on fire activity; cooler Banda Sea leads drought and stronger fire activityFire activity is sensitively driven by local SST changes due to strong local air‐sea interaction in October [ABSTRACT FROM AUTHOR]