WE WILL USE U.S. AURA SATELLITE OBSERVATIONS TO (1) IMPROVE THE SUITE OF AVAILABLE GLOBAL AIR QUALITY INDICATORS AND (2) PERFORM SCIENTIFIC STUDIES USING MULTIPLE PRODUCTS TO ADDRESS ONGOING ISSUES IN ATMOSPHERIC CHEMISTRY AND AIR QUALITY. WE WILL: PROVIDE IMPROVED ERROR ESTIMATES FOR SAO LEVEL 2 DATA PRODUCTS; PRODUCE LEVEL 3 DATA PRODUCTS FOR H2CO C2H2O2 H2O AND BRO; PERFORM BIOMASS BURNING STUDIES TO BETTER UNDERSTAND OXIDATION AND O3 PRODUCTION; QUANTIFY THE EFFECTS OF AEROSOLS ON TRACE GAS PRODUCTS; INVESTIGATE ECONOMIC ASPECTS OF EMISSIONS AND AIR QUALITY; DEVELOP AND UTILIZE A H2O ATMOSPHERIC RIVER PRODUCT; IMPROVE THE DETERMINATION OF BRO AS A PRODUCT OF VOLCANIC ERUPTIONS. IN ORDER TO PERFORM THIS RESEARCH WE WILL USE TOOLS THAT HAVE BEEN DEVELOPED OVER THE YEARS FOR SATELLITE MEASUREMENTS BY SAO AND OUR COLLABORATORS. THESE INCLUDE THE SAO FITTING ALGORITHMS USED OPERATIONALLY ON OMI FOR H2CO BRO OCLO AND NOW FOR C2H2O2 AND H2O. THEY ALSO INCLUDE THE GEOS-CHEM 3-D CHEMISTRY AND TRANSPORT MODEL (CTM) DEVELOPED AT HARVARD; THE VLIDORT DISCRETE ORDINATE MULTIPLE-SCATTERING RADIATIVE TRANSFER CODE [SPURR 2006]; AND AEROSOL MEASUREMENT CAPABILITIES DEVELOPED FOR OMI AND MODIS. OUR RESEARCH WILL IMPROVE MEASUREMENTS AND THE LONG-TERM RECORD FOR TRACE GASES THAT ARE CENTRAL TO UNDERSTANDING CLIMATE CHANGE AND AIR QUALITY. IT ADDRESSES ALL OF THE SCIENCE QUESTIONS WITHIN THE NASA ATMOSPHERIC COMPOSITION FOCUS AREA: HOW IS ATMOSPHERIC COMPOSITION CHANGING? WHAT TRENDS IN ATMOSPHERIC COMPOSITION AND SOLAR RADIATION ARE DRIVING GLOBAL CLIMATE? HOW DOES ATMOSPHERIC COMPOSITION RESPOND TO AND AFFECT GLOBAL ENVIRONMENTAL CHANGE? WHAT ARE THE EFFECTS OF GLOBAL ATMOSPHERIC COMPOSITION AND CLIMATE CHANGES ON REGIONAL AIR QUALITY? HOW WILL FUTURE CHANGES IN ATMOSPHERIC COMPOSITION AFFECT OZONE CLIMATE AND GLOBAL AIR QUALITY? IN TERMS OF THE SOLICITATION GOALS OUR RESEARCH: DEVELOPS NEW DATA PRODUCTS FROM THE EOS AURA INSTRUMENTS USING LEVEL 2 DATA; DEVELOPS NEW AND SIGNIFICANTLY IMPROVED LEVEL 2 DATA THAT ARE NOT SUPPORTED BY THE AURA PROJECT CORE DATA ANALYSIS BUDGET; USES AURA DATA TO TRACK CHANGES IN STRATOSPHERIC AND TROPOSPHERIC COMPOSITION DETERMINES THE EXCHANGE OF TRACE GASES WITHIN THE TROPOSPHERE BETWEEN THE STRATOSPHERE AND TROPOSPHERE AND ESTIMATES THE TRANSPORT PROPERTIES OF THE STRATOSPHERE AND UPPER TROPOSPHERE; USES OMI DATA SETS TO STUDY TROPOSPHERIC AIR QUALITY AND OXIDIZING CAPACITY OF THE TROPOSPHERE INCLUDING THE EFFECTS OF CLIMATE CHANGE ON TROPOSPHERIC AIR QUALITY AND AIR QUALITY ON CLIMATE AND STUDIES OF THE ATTRIBUTION OF CHANGES IN AIR QUALITY AND OXIDIZING CAPACITY OVER THE PAST 20 YEARS; USES AURA DATA TO BETTER MERGE THE ACTIVITIES OF THE ATMOSPHERIC COMPOSITION RESEARCH COMMUNITY AND AIR QUALITY MONITORING ACTIVITIES OF OTHER AGENCIES WITHIN THE UNITED STATES. ALL PRODUCTS AND PUBLICATIONS WILL BE AVAILABLE AT HTTP://WWW.CFA.HARVARD.EDU/ATMOSPHERE/.