Numerical simulations examining the possible role of anthropogenic and volcanic emissions during the 1997 Indonesian fires

Abstract

The regional atmospheric chemistry and climate model REMOTE has been used to conduct numerical simulations of the atmosphere during the catastrophic Indonesian fires of 1997. These simulations represent one possible scenario of the event, utilizing the RETRO wildland fire emission database. Emissions from the fires dominate the atmospheric concentrations of O₃, CO, NO₂, and SO₂ creating many possible exceedances of the Indonesian air quality standards. The scenario described here suggests that urban anthropogenic emissions contributed to the poor air quality due primarily to the fires. The urban air pollution may have increased the total number of people exposed to exceedances of the O₃ 1-h standard by 17%. Secondary O₃ from anthropogenic emissions enhanced the conversion of SO₂ released by the fires to \( {\rm{SO}}_4^{2-}\), demonstrating that the urban pollution actively altered the atmospheric behavior and lifetime of the fire emissions. Under the conditions present during the fires, volcanic SO₂ emissions had a negligible influence on surface pollution.