Observational data-driven surface concentrations derived from satellite columns and aircraft profiles

SURFACE OZONE AND FINE PARTICULATE MATTER ARE AMONG THE MOST IMPORTANT ATMOSPHERIC POLLUTANTS THAT ARE MAINLY FORMED SECONDARILY IN THE ATMOSPHERE. NITROGEN OXIDES VOLATILE ORGANIC COMPOUNDS (VOCS) AND AMMONIA ARE KEY PRECURSORS TO OZONE AND SECONDARY AEROSOLS WITH IMPLICATIONS FOR AIR QUALITY ECOSYSTEM HEALTH AND THE CLIMATE. IN THE US THE EMISSIONS OF NITROGEN OXIDES HAVE BEEN DECREASING SHARPLY OVER THE LAST DECADE DUE TO EFFECTIVE REGULATIONS BUT THE CONTROL OF AMMONIA AND VOC EMISSIONS LAGS BEHIND. ALSO THE MAJOR EMISSION SOURCES FOR NITROGEN OXIDES AMMONIA AND VOCS ARE SPATIALLY SEGREGATED IN THE US WITH NITROGEN OXIDES SOURCES CLUSTERING IN URBAN AREAS AMMONIA EMITTED LARGELY FROM AGRICULTURAL ACTIVITIES AND BIOGENIC VOC DOMINATING THE VOC REACTIVITY OVER A LARGE AREA IN THE EASTERN US. CONSEQUENTLY THERE ARE POTENTIALLY SHIFTS OF CHEMICAL REGIMES IN OZONE AND SECONDARY AEROSOL FORMATION AND THE CHANGING PATTERNS SHOW STRONG SPATIAL AND TEMPORAL VARIABILITY DUE TO THE MISMATCH OF EMISSIONS IN BOTH SPACE AND TIME. SATELLITE OBSERVATIONS FROM VARIOUS SENSORS PROVIDE EXCELLENT SPATIOTEMPORAL COVERAGE FOR AMMONIA NITROGEN DIOXIDE AND FORMALDEHYDE A HIGH-YIELD PRODUCT FROM THE OXIDATION OF VOCS. HOWEVER SATELLITES USUALLY ONLY MEASURE THE VERTICALLY INTEGRATED COLUMN DENSITY INSTEAD OF THE SURFACE CONCENTRATIONS THAT ARE MOST RELEVANT TO AIR QUALITY AND HUMAN/ECOSYSTEM HEALTH. WE PROPOSE A 3-YEAR STUDY TO DEVELOP LONG-TERM (FROM THE LAUNCH OF AURA IN 2004) SURFACE CONCENTRATIONS OF ATMOSPHERIC AMMONIA NITROGEN DIOXIDE AND FORMALDEHYDE OVER THE CONTIGUOUS UNITED STATES (CONUS). WE WILL PRODUCE SPATIALLY AND TEMPORALLY RESOLVED MAPS OF SURFACE CONCENTRATIONS BY MERGING DATA FROM SATELLITE COLUMNS AIRCRAFT TRACE GAS VERTICAL PROFILES PLANETARY BOUNDARY LAYER HEIGHT (PBLH) MEASURED BY COMMERCIAL AIRLINES METEOROLOGICAL REANALYSIS AND CHEMICAL TRANSPORT MODEL (CTM) SIMULATIONS. WE WILL SYNTHESIZE SATELLITE PRODUCTS FROM TES IASI CRIS AND OMI AS WELL AS SUBORBITAL MISSIONS SUCH AS DISCOVER-AQ. ALL DERIVED SURFACE CONCENTRATIONS WILL BE OVERSAMPLED TO A COMMON HIGH-RESOLUTION GRID USING STATE-OF-THE-ART GRIDDING ALGORITHMS AND VALIDATED USING GROUND-BASED IN SITU OBSERVATIONS. THE PROPOSED RESEARCH WILL CONSIST OF (1) DERIVING REPRESENTATIVE PBLH-BASED VERTICAL PROFILES FOR AMMONIA NITROGEN DIOXIDE AND FORMALDEHYDE FROM AIRCRAFT MEASUREMENTS (2) CONSTRUCTING SPATIOTEMPORALLY RESOLVED PBLH USING COMMERCIAL AIRLINE AND REANALYSIS DATA AND (3) DERIVING/OVERSAMPLING SURFACE CONCENTRATION DATA AND VALIDATING THE RESULTS. THE OUTCOME OF THE PROPOSED RESEARCH WILL HELP ADDRESS IMPORTANT SCIENTIFIC QUESTIONS ABOUT THE CHANGING PATTERN OF REACTIVE NITROGEN AND VOC EMISSIONS AS WELL AS THE SHIFTING CHEMICAL REGIMES OF OZONE AND SECONDARY AEROSOL FORMATION. THE PROPOSED STUDY DIRECTLY RESPONDS TO NASA S SOLICITED INVESTIGATION IN NRA A. 19 ATMOSPHERIC COMPOSITION: MODELING AND ANALYSIS (ACMAP) BY INVESTIGATING THE ATTRIBUTION OF CHANGES IN TROPOSPHERIC AIR QUALITY AND OXIDIZING CAPACITY OVER THE PAST 20 YEARS. OUR PROPOSED RESEARCH ALIGNS WITH THE NASA STRATEGIC OBJECTIVE ADVANCE KNOWLEDGE OF EARTH AS A SYSTEM TO MEET THE CHALLENGES OF ENVIRONMENTAL CHANGE AND TO IMPROVE LIFE IN OUR PLANET AND NASA SCIENCE PLAN ADVANCE THE UNDERSTANDING OF CHANGE IN THE EARTH S RADIATION BALANCE AIR QUALITY AND THE OZONE LAYER THAT RESULT FROM CHANGES IN ATMOSPHERIC COMPOSITION.