SOIL/MINERAL DUST PARTICLES ARE HIGHLY ABUNDANT BY MASS IN THE ATMOSPHERE AND THEY PLAY AN IMPORTANT ROLE IN MANY ATMOSPHERIC PROCESSES. THEY CHANGE THE RADIATION FLUXES ARE INVOLVED IN CLOUD FORMATION ACT AS CARRIER OF NUTRIENTS AFFECTING BIOGEOCHEMICAL CYCLES. DUST IS ALSO AN IMPORTANT FACTOR IN TROPOSPHERIC CHEMISTRY SINCE MINERAL SURFACES REACT WITH TRACE GASES AND ADSORB WATER VAPOR. THE INTERACTION OF DUST IN THESE PROCESSES DEPENDS ON FUNDAMENTAL DUST PROPERTIES SUCH A THE MINERALOGICAL COMPOSITION MORPHOLOGY OF THE PARTICLE SURFACES AND PARTICLE SIZE. WHILE MOST GLOBAL MODELS ONLY CONSIDER ONE GLOBALLY UNIFORM DUST TYPE AN IMPROVED VERSION OF THE DUST MODULE HAS RECENTLY BEEN DEVELOPED IN NATIONAL AERONAUTICS AND SPACE ADMINISTRATION (NASA) GODDARD INSTITUTE FOR SPACE STUDIES (GISS) EARTH SYSTEM MODEL "MODELE" WHICH DISTINGUISHES INDIVIDUAL MINERAL SPECIES. IN THE PROPOSED PROJECT THIS DUST MINERAL VERSION OF THE MODEL IS BEING EVALUATED AGAINST SATELLITE (SUCH AS CALIPSO MODIS MISR AVHRR SEAWIFS) AND GROUND BASED MEASUREMENTS (SUCH AS AERONET CASTNET IMPROVE EMEP) OF AEROSOL PROPERTIES AND TRACE GASES WHICH ARE AFFECTED BY HETEROGENEOUS CHEMICAL PROCESSES ON DUST MINERAL SURFACES. FURTHERMORE ESTIMATES OF THE EFFECT OF DUST HETEROGENEOUS CHEMISTRY ON RADIATIVE FORCING AND ITS UNCERTAINTY WILL BE PROVIDED. FOLLOWING MAIN SCIENCE QUESTIONS WILL BE ADDRESSED IN THE PROJECT: .1. DOES MINERAL SPECIFIC HETEROGENEOUS CHEMISTRY IMPROVE THE REPRESENTATION OF DUST AEROSOLS AS WELL AS OF OTHER AEROSOLS AND TRACE GASES AFFECTED BY THIS CHEMISTRY IN NASA GISS EARTH SYSTEM MODELE3 WHEN COMPARED TO SATELLITE AND GROUND BASED OBSERVATIONS? .2. WHAT IS THE UNCERTAINTY RANGE OF RADIATIVE FORCING OF CLIMATE BY DUST AEROSOLS SULFATE AND NITRATE AEROSOLS AND RADIATIVELY ACTIVE PRECURSOR GASES DUE TO THE RANGE OF UNCERTAINTY IN DUST MINERAL SPECIFIC HETEROGENEOUS CHEMISTRY FOR PRE-INDUSTRIAL PRESENT-DAY AND FUTURE CLIMATE? WHAT IS THE RANGE OF CHANGES IN RADIATIVE FORCING BETWEEN THESE CLIMATE STATES DUE TO THE UNCERTAINTY? .THE FIRST SCIENCE QUESTION WILL BE ADDRESSED BY EVALUATING MODEL SIMULATED DUST CASES AND SIMULATED OTHER AEROSOLS AND TRACE GAS FIELDS THAT ARE AFFECTED BY DUST HETEROGENEOUS CHEMISTRY AGAINST AVAILABLE SATELLITE AND GROUND BASED MEASUREMENTS OVER THE TOTAL TIME PERIOD FROM 1980 TO 2018. THE SECOND SCIENCE QUESTION WILL BE ADDRESSED BY DERIVING RADIATIVE FORCING ESTIMATES FROM 30 YEAR SIMULATIONS FOR PRE-INDUSTRIAL PRESENT DAY AND FUTURE CLIMATE. .THE UTILIZATION OF NASA SATELLITE AND GROUND BASED PRODUCTS FOR EVALUATION AND THE STUDY OF CHEMICAL PROCESSES THAT DEPEND ON DUST AEROSOL CHARACTERISTICS IN A NASA EARTH SYSTEM MODEL MAKES THIS PROPOSAL RELEVANT TO THE ATMOSPHERIC COMPOSITION: MODELING AND ANALYSIS PROGRAM IN GENERAL AND TO RESEARCH AREA B OF THE CURRENT PROGRAM SOLICITATION IN PARTICULAR. HENCE THE PROPOSAL IS ALSO RELEVANT TO THE EARTH SCIENCE QUESTIONS AND GOALS IN THE NASA SCIENCE PLAN AND TO NASA. .