MORE THAN 80% OF PEOPLE LIVING IN URBAN AREAS THAT MONITOR AIR POLLUTION ARE EXPOSED TO AIR QUALITY LEVELS THAT EXCEED WHO LIMITS. AMBIENT AIR POLLUTION MADE OF HIGH CONCENTRATIONS OF FINE PARTICULATE MATTER PM2.5 IS THE GREATEST ENVIRONMENTAL RISK TO HEALTH - CAUSING MORE THAN 3 MILLION PREMATURE DEATHS WORLDWIDE EVERY YEAR. PM2.5 INCLUDE POLLUTANTS SUCH AS SULFATE NITRATES AND BLACK CARBON WHICH PENETRATE DEEP INTO THE LUNGS AND INTO THE CARDIOVASCULAR SYSTEM POSING THE GREAT RISKS TO HUMAN HEALTH. WHILE ALL REGIONS OF THE WORLD ARE AFFECTED AIR POLLUTION LEVELS ARE RISING MOST IN MANY OF THE WORLD'S POOREST CITIES. REGIONAL AND GLOBAL AIR POLLUTION/CLIMATE MODELS ARE TYPICALLY USED FOR THE AIR QUALITY ASSESSMENTS. CONVENTIONALLY THESE MODELS GET VALIDATED PRIOR TO THEIR USAGE THROUGH AIR QUALITY MEASUREMENTS THAT ARE DONE AT THE SURFACE THROUGH GROUND-BASED MONITORS. HOWEVER THE ACCURATE MEASUREMENTS OF FINE PARTICLES RELY ON EXPENSIVE EQUIPMENT REDUCING THE EXTENT OF SPATIAL MONITORING PARTICULARLY IN THE DEVELOPING WORLD. SATELLITE REMOTE SENSING FOR SURFACE AIR QUALITY HAS DEVELOPED RAPIDLY OVER THE PAST DECADE WITH NUMEROUS ATTEMPTS TO LINK AEROSOL OPTICAL DEPTH (AOD) WITH SURFACE PM2.5 CONCENTRATION. THE CURRENT WORK ADVANCES THE DEMONSTRATED RELATIONSHIP BETWEEN THE AOD AND SURFACE PM2.5 BY INTRODUCING HIGH SPECTRAL RESOLUTION LIDAR (HSRL)-DERIVED AEROSOL TYPES (URBAN SMOKE FRESH SMOKE DUST/ DUSTY MIX AND MARITIME/POLLUTED MARITIME) AS A CONSTRAINT FOR PARTICLE CHEMICAL COMPOSITION. BY QUANTIFYING THE LINKAGES BETWEEN THE AEROSOL TYPES AND THEIR RELATIVE CHEMICAL COMPOSITION (I.E. FRACTIONAL CONTRIBUTION OF SULFATES NITRATES BLACK CARBON ORGANICS SEA-SALT AND DUST) THE CURRENT METHOD AIMS TO IMPROVE SURFACE PM2.5 MODEL PREDICTIONS. THE REMOTE SENSING COMPONENT OF THE PROPOSED STUDY IS FROM HSRL AEROSOL TYPES RETRIEVED DURING DISCOVER-AQ (DERIVING INFORMATION ON SURFACE CONDITIONS FROM COLUMN AND VERTICALLY RESOLVED OBSERVATIONS RELEVANT TO AIR QUALITY) WASHINGTON CORRIDOR (BWC) CAMPAIGN. THE MODELING COMPONENT IS THE EPA'S CMAQ (COMMUNITY MULTISCALE AIR QUALITY) MODEL. THE LINKAGE BETWEEN THE REMOTELY SENSED AND THE MODELED DATA IS PROVIDED BY CATCH (CREATING AEROSOL TYPES FROM CHEMISTRY) - A RECENTLY DEVELOPED ALGORITHM THAT THAT TAKES MODEL-PREDICTED DATA