(1) TO USE THE GEOS-CHEM ADJOINT MODEL AND MULTI-SENSOR DATA (MODIS CLOUD-FREE RADIANCE OMI SO2 AND NO2 DATA) TO CONSTRAIN AEROSOL SOURCE EMISSIONS ON A MONTHLY BASIS OVER EAST ASIA IN 2006 2008 2010 AND 2012 THE YEARS WHEN BOTTOM-UP (PRIOR) ESTIMATES OF EMISSIONS AND/OR FIELD CAMPAIGN DATA ARE ALSO AVAILABLE; (2) TO ASCERTAIN HOW REDUCING UNCERTAINTY IN AEROSOL EMISSION IMPACTS ESTIMATES OF THE AEROSOL DIRECT RADIATIVE FORCING AND THE TRANSBOUNDARY TRANSPORT FROM EAST ASIA TO THE UNITED STATES BY CONTRASTING THE TWO GEOS-CHEM RESULTS RESPECTIVELY SIMULATED WITH THE TOP-DOWN EMISSION INVENTORY AND THE PRIOR BOTTOM-UP EMISSION INVENTORY; (3) TO CHARACTERIZE THE UNCERTAINTY AND VALIDATE THE RESULTS WITH DATA FROM OTHER INDEPENDENT SOURCES (E.G. NASA FIELD CAMPAIGNS GROUND-BASED NETWORK SUCH AS AERONET DOE FIELD CAMPAIGN IN CHINA AND MISR AND OMI AOD).