Earth Observation Research Center, Japan Aerospace Exploration Agency
Center for Climate System Research, The University of Tokyo
抄録
We performed an experiment under ideal conditionsusing a general circulation model and found thataerosols can play an important role in altering the precipitationin Asia. Emissions of anthropogenic aerosolsare increasing in Asia, affecting the global and regionalclimates through their direct and indirect effects.However, the link between aerosol loading and climatechange due to these effects is still difficult to understand.The present study was based on a threedimensionalaerosol transport model coupled with amixed-layer ocean model; it focused on the effects ofanthropogenic aerosols on boreal summer precipitationover Asia. We investigated these effects by taking differencesbetween the results of equilibrium runs withpre-industrial and current fossil fuel burning aerosol(FFA) conditions. In this model simulation, aerosolloading changed the circulation field through changesin the radiation budget. The indirect effects of aerosolsinclude not only the first and second indirect effects butalso the effects of these changes. Our results show thatan increase in anthropogenic aerosols reduces precipitationdue to weaker convection with both surface coolingand sea surface temperature (SST) changes. This mechanismis the most effective way for aerosols to impactprecipitation in this model simulation.
雑誌名
SOLA : Scientific online letters on the atomsphere