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We use an ensemble of surface (EPA CSN, IMPROVE , SEARCH, AERONET), aircraft (SEAC 4 RS), and satellite (MODIS, MISR) observations over the southeast US during the summer–fall of 2013 to better understand aerosol sources in the region and the relationship between surface particulate matter (PM) and aerosol optical depth (AOD). The GEOS-Chem global chemical(More)
Smoke exposure sensitivity to Equatorial Asian fires computed with adjoint model. Protecting Sumatran peatswamp forests is key to future regional air quality. The GEOS-Chem adjoint can provide guidance for targeted land conservation. a b s t r a c t High smoke concentrations in Equatorial Asia, primarily from land conversion to oil palm plantations, affect(More)
This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP if available. Abstract Isoprene emitted by vegetation is an important precursor of secondary organic aerosol (SOA), but the mechanism and yields are uncertain. Aerosol is prevailingly aqueous under the(More)
32 33 We present a global data set of free tropospheric ozone-CO correlations with 2 o × 2.5 o 34 spatial resolution from the OMI and AIRS satellite instruments for each season of 2008. 35 OMI (ozone) and AIRS (CO) have near daily global coverage and observe coincident 36 scenes with similar vertical sensitivities. The resulting ozone-CO correlations are(More)
Formaldehyde (HCHO) column data from satellites are widely used as a proxy for emissions of volatile organic compounds (VOCs), but validation of the data has been extremely limited. Here we use highly accurate HCHO aircraft observations from the NASA SEAC 4 RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys)(More)
Formation of ozone and organic aerosol in continental atmospheres depends on whether isoprene emitted by vegetation is oxidized by the high-NO x pathway (where per-oxy radicals react with NO) or by low-NO x pathways (where peroxy radicals react by alternate channels, mostly with HO 2). We used mixed layer observations from the SEAC 4 RS aircraft campaign(More)
Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NO x ≡ NO + NO 2) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We(More)
Acid-base neutralization of sulfate aerosol (S(VI) ≡ H 2 SO 4 (aq) + HSO 4-+ SO 4 2-) by ammonia (NH 3) has important implications for aerosol mass, hygroscopicity, and acidity. Surface network and aircraft observations across the eastern US show that sulfate aerosol is not fully neutralized even in the presence of excess ammonia, at odds with thermodynamic(More)
Glyoxal (CHOCHO) is produced in the atmosphere by oxidation of volatile organic compounds (VOCs). It is measurable from space by solar backscatter along with formaldehyde (HCHO), another oxidation product of VOCs. Isoprene emitted by vegetation is the dominant source of CHOCHO and HCHO in most of the world. We use aircraft observations of CHOCHO and HCHO(More)
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