Simulated changes in Southeast Asian monsoon precipitation resulting from anthropogenic emissions

Abstract

Examined here is the effect on simulated monsoon precipitation of the Intergovernmental Panel on Climate Change (IPCC) IS92a non-intervention anthropogenic emissions scenario (Leggett et al., 1992) over Southeast Asia. By the middle of the next century, increases in greenhouse gases enhance monsoon precipitation by 1% (a net reduction of 7% with aerosol added), though the changes are far from uniform across the region. The monsoon onset date is delayed by about 10 days in the west (15 days when sulphate effects are included). The range of precipitation intensity over the region broadens, with decreases prevalent in the west and increases more widespread in the east. Although the details of the changes are likely to be model dependent, the simulations indicate that changes in mean monsoon precipitation are likely to be accompanied by substantial changes in other characteristics of the monsoon including the date of onset and precipitation intensity. © 1998 Royal Meteorological Society