Aerosol and Clouds

Synthesis of satellite (MODIS), aircraft (ICARTT), and surface (IMPROVE, EPA-AQS, AERONET) aerosol observations over eastern North America to improve MODIS aerosol retrievals and constrain surface aerosol concentrations and sources

  1. Easan Drury1,2,
  2. Daniel J. Jacob1,
  3. Robert J. D. Spurr3,
  4. Jun Wang4,
  5. Yohei Shinozuka5,
  6. Bruce E. Anderson6,
  7. Antony D. Clarke7,
  8. Jack Dibb8,
  9. Cameron McNaughton7,
  10. Rodney Weber9

Article first published online: 24 JUL 2010

DOI: 10.1029/2009JD012629

Issue

Journal of Geophysical Research: Atmospheres (1984–2012)

Journal of Geophysical Research: Atmospheres (1984–2012)

Additional Information

How to Cite

Drury, E., D. J. Jacob, R. J. D. Spurr, J. Wang, Y. Shinozuka, B. E. Anderson, A. D. Clarke, J. Dibb, C. McNaughton, and R. Weber (2010), Synthesis of satellite (MODIS), aircraft (ICARTT), and surface (IMPROVE, EPA-AQS, AERONET) aerosol observations over eastern North America to improve MODIS aerosol retrievals and constrain surface aerosol concentrations and sources, J. Geophys. Res., 115, D14204, doi:10.1029/2009JD012629.

Author Information

  1. 1

    School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA

  2. 2

    National Renewable Energy Laboratory, Golden, Colorado, USA

  3. 3

    RT Solutions, Inc., Cambridge, Massachusetts, USA

  4. 4

    Department of Geosciences, University of Nebraska, Lincoln, Nebraska, USA

  5. 5

    NASA Ames Research Center, Moffett Field, California, USA

  6. 6

    NASA Langley Research Center, Hampton, Virginia, USA

  7. 7

    School of Ocean and Earth Science and Technology, University of Hawaii, Manoa, Hawaii, USA

  8. 8

    Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire, USA

  9. 9

    School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA

Publication History

  1. Issue published online: 24 JUL 2010
  2. Article first published online: 24 JUL 2010
  3. Manuscript Accepted: 24 FEB 2010
  4. Manuscript Revised: 15 JAN 2010
  5. Manuscript Received: 10 JUN 2009

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

View Full Article with Supporting Information (HTML) Get PDF (2614K)

Keywords:

  • aerosols;
  • PM2.5;
  • MODIS

[1] We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations (PM2.5) from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and locations. We use an improved MODIS AOD retrieval based on locally derived visible surface reflectances and aerosol properties calculated from GEOS-Chem. Use of GEOS-Chem aerosol optical properties in the MODIS retrieval not only results in an improved AOD product but also allows quantitative evaluation of model aerosol mass from the comparison of simulated and observed AODs. The aircraft measurements show narrower aerosol size distributions than those usually assumed in models, and this has important implications for AOD retrievals. Our MODIS AOD retrieval compares well to the ground-based AERONET data (R = 0.84, slope = 1.02), significantly improving on the MODIS c005 operational product. Inference of surface PM2.5 from our MODIS AOD retrieval shows good correlation to the EPA-AQS data (R = 0.78) but a high regression slope (slope = 1.48). The high slope is seen in all AOD-inferred PM2.5 concentrations (AERONET: slope = 2.04; MODIS c005: slope = 1.51) and could reflect a clear-sky bias in the AOD observations. The ensemble of MODIS, aircraft, and surface data are consistent in pointing to a model overestimate of sulfate in the mid-Atlantic and an underestimate of organic and dust aerosol in the southeastern United States. The sulfate overestimate could reflect an excessive contribution from aqueous-phase production in clouds, while the organic carbon underestimate could possibly be resolved by a new secondary pathway involving dicarbonyls.

View Full Article with Supporting Information (HTML) Get PDF (2614K)