The ENSO-fire Dynamic in Insular Southeast Asia

We examined the spatiotemporal patterns of fire in insular Southeast Asia from July 1996-December 2001 using a set of consistent, nighttime fire observations provided by the Along Track Scanning Radiometer (ATSR) sensor. Monthly ATSR fire counts were analyzed relative to georeferenced climatic and land-cover data from a variety of sources. We found that fires were strongly correlated with Southern Oscillation Index (SOI) (r = -0.75) and Nino 3.4 index (r = 0.72) in forested land-cover types within the equatorial belt (-5.5 to 5.5 degrees). Cross-correlation analysis revealed that detrended SOI was modestly correlated (r = 0.42) with detrended monthly fire count with a positive lag of four months. However, our analysis also revealed that fire counts reached their maximum six months before the absolute maximum of SOI. Annual sums of SOI and fire counts revealed linearity for annual SOI sum less than zero. Overall, the results suggest that ENSO indices may have limited predictive utility at a monthly time scale, but that temporal aggregation and additional fire observations may enhance our capacity to forecast fires in different cover types based on ENSO data.