Aerosol Optical Depth over Oceans: High Space- and Time-Resolution Retrieval and Error Budget from Satellite Radiometry

Richard Wagener Analytical Sciences Division, Brookhaven National Laboratory, Upton, New York

Search for other papers by Richard Wagener in
Current site
Google Scholar
PubMed
Close
,
Seth Nemesure Environmental Chemistry Division, Brookhaven National Laboratory, Upton, New York

Search for other papers by Seth Nemesure in
Current site
Google Scholar
PubMed
Close
, and
Stephen E. Schwartz Environmental Chemistry Division, Brookhaven National Laboratory, Upton, New York

Search for other papers by Stephen E. Schwartz in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

A method to retrieve aerosol vertical optical depth at 0.64 μm from satellite observations of cloud-free scenes over oceans with high spatial resolution (∼1°) and instantaneous temporal resolution is described and evaluated. The observed radiance is treated as the linear sum of contributions to path radiance by different scattering processes in the atmosphere–ocean system. This treatment allows examination of errors in the retrieved vertical aerosol optical depth contributed by each process and approximation. Random error in retrieved aerosol optical depth is typically 0.03. The systematic error due to absolute calibration uncertainty in the measured radiance is 0.01. The largest errors and biases are due to radiative transfer approximations (+22%) and assumptions regarding aerosol microphysical and optical properties (−20%). The latter errors, which are due to the optical properties (e.g., phase function), vary systematically with latitude and season because of the variation of the mean observing geometry.

This method is applied to Advanced Very High Resolution Radiometer global area coverage data, and example maps of aerosol optical depth are presented for specific dates in July and October 1986. The aerosol optical depth derived from the satellite data is suitable for examining large aerosol signatures by instantaneous comparison of the amplitude and location of aerosol plumes with model predictions based on meteorological conditions at and preceding the time of observation.

Corresponding author address: Dr. Stephen Schwartz, Department of Applied Science, Brookhaven National Laboratory, Bldg. 426, 51 Bell Ave., P.O. Box 5000, Upton, NY 11973-5000.

Email: ses@bnl.gov

Abstract

A method to retrieve aerosol vertical optical depth at 0.64 μm from satellite observations of cloud-free scenes over oceans with high spatial resolution (∼1°) and instantaneous temporal resolution is described and evaluated. The observed radiance is treated as the linear sum of contributions to path radiance by different scattering processes in the atmosphere–ocean system. This treatment allows examination of errors in the retrieved vertical aerosol optical depth contributed by each process and approximation. Random error in retrieved aerosol optical depth is typically 0.03. The systematic error due to absolute calibration uncertainty in the measured radiance is 0.01. The largest errors and biases are due to radiative transfer approximations (+22%) and assumptions regarding aerosol microphysical and optical properties (−20%). The latter errors, which are due to the optical properties (e.g., phase function), vary systematically with latitude and season because of the variation of the mean observing geometry.

This method is applied to Advanced Very High Resolution Radiometer global area coverage data, and example maps of aerosol optical depth are presented for specific dates in July and October 1986. The aerosol optical depth derived from the satellite data is suitable for examining large aerosol signatures by instantaneous comparison of the amplitude and location of aerosol plumes with model predictions based on meteorological conditions at and preceding the time of observation.

Corresponding author address: Dr. Stephen Schwartz, Department of Applied Science, Brookhaven National Laboratory, Bldg. 426, 51 Bell Ave., P.O. Box 5000, Upton, NY 11973-5000.

Email: ses@bnl.gov

Save
  • Benkovitz, C. M., C. M. Berkowitz, R. C. Easter, S. Nemesure, R. Wagener, and S. E. Schwartz, 1994: Sulfate over the North Atlantic and adjacent continental regions: Evaluation for October and November, 1986 using a three-dimensional model driven by observation-derived meteorology. J. Geophys. Res.,99, 20 725–20 756.

    • Crossref
    • Export Citation
  • Berkowitz, C. M., S. J. Ghan, C. M. Benkovitz, R. Wagener, S. Nemesure, and S. E. Schwartz, 1994: Evaluation of sulfate aerosol optical depths over the North Atlantic and comparison with satellite observations. Preprints, Conf. on Atmospheric Chemistry, Nashville, TN, Amer. Meteor. Soc., 154–160.

  • Boucher, O., and T. L. Anderson, 1995: GCM assessment of the sensitivity of direct climate forcing by anthropogenic sulfate aerosols to aerosol size and chemistry. J. Geophys. Res.,100, 26 117–26 134.

    • Crossref
    • Export Citation
  • Charlson, R. J., J. Langner, H. Rodhe, C. B. Leovy, and S. G. Warren, 1991: Perturbation of the Northern Hemisphere radiative balance by backscattering from anthropogenic sulfate aerosols. Tellus,43AB, 152–163.

    • Crossref
    • Export Citation
  • ———, S. E. Schwartz, J. M. Hales, R. D. Cess, J. A. Coakley Jr., J. E. Hansen, and D. J. Hofmann, 1992: Climate forcing by anthropogenic aerosols. Science,255, 423–430.

    • Crossref
    • Export Citation
  • Cleveland, W., 1979: Robust locally weighted regression and smoothing scatterplots. J. Amer. Stat. Assoc.,74, 829–836.

    • Crossref
    • Export Citation
  • Cox, C., and W. Munk, 1956: Slopes of the sea surface deduced from photographs of sun glitter. Bull. Scripps Inst. Oceanogr.,6, 401–488.

  • d’Almeida, G. A., P. Koepke, and E. P. Shettle, 1991: Atmospheric Aerosols: Global Climatology and Radiative Characteristics. A. Deepak Publishing, 561 pp.

  • Durkee, P. A., F. Pfeil, E. Frost, and R. Shema, 1991: Global analysis of aerosol particle characteristics. Atmos. Environ.,25A, 2457–2471.

    • Crossref
    • Export Citation
  • European Centre for Medium-Range Weather Forecasts, Research Department, 1988: ECMWF forecast model: Adiabatic part. Research manual, ECMWF.

  • Feldman, G., and Coauthors, 1989: Ocean color: Availability of the global data set. Eos, Trans. Amer. Geophys. Union,70, 634–641.

    • Crossref
    • Export Citation
  • Gordon, H. R., and A. Y. Morel, 1983: Remote Assessment of Ocean Color for Interpretation of Satellite Visible Imagery: A Review. Vol. 4, Lecture Notes on Coastal and Estuarine Studies, Springer-Verlag, 114 pp.

    • Crossref
    • Export Citation
  • ———, J. W. Brown, and R. H. Evans, 1988: Exact Rayleigh scattering calculations for use with the Nimbus-7 Coastal Zone Color Scanner. Appl. Opt.,27, 862–871.

    • Crossref
    • Export Citation
  • Gregg, W. W., and K. L. Carder, 1990: A simple spectral solar irradiance model for cloudless maritime atmospheres. Limnol. Oceanogr.,35, 1657–1675.

    • Crossref
    • Export Citation
  • Guimaraes, P. T., and R. McPeters, 1990: TOMS gridded ozone data 1978–1988. Version 6.0. NASA Goddard Space Flight Center, CD-ROM.

  • Hansen, J., and L. Travis, 1974: Light scattering in planetary atmospheres. Space Sci. Rev.,16, 527–610.

    • Crossref
    • Export Citation
  • ———, W. Rossow, and I. Fung, Eds., 1993: Long-term Monitoring of Global Climate Forcings and Feedbacks. NASA Conf. Publ. Vol. 3234, NASA Goddard Institute for Space Studies, New York, NY, 91 pp.

  • Hoppel, W. A., J. W. Fitzgerald, G. M. Frick, and R. E. Larson, 1990: Aerosol size distributions and optical properties found in the marine boundary layer over the Atlantic Ocean. J. Geophys. Res.,95, 3659–3686.

    • Crossref
    • Export Citation
  • Houghton, J. T., B. A. Callander, and S. K. Varney, Eds., 1992: Climate Change 1992: The Supplementary Report to the IPCC Scientific Assessment. Cambridge University Press, 200 pp.

  • ———, L. G. Meira Filho, J. Bruce, H. Lee, D. A. Callander, E. Haipes, N. Harris, and K. Maskell, Eds., 1994: Climate Change 1994: Radiative Forcing of Climate Change and an Evaluation of the IPCC 1992 Emission Scenarios. Cambridge University Press, 339 pp.

  • Hovis, W. A., and Coauthors, 1980: Nimbus-7 Coastal Zone Color Scanner: System description and initial imagery. Science,210, 60–63.

    • Crossref
    • Export Citation
  • Husain, L., and V. A. Dutkiewicz, 1990: A long-term (1975–1988) study of atmospheric SO2− 4: Regional contributions and concentration trends. Atmos. Environ.,24A, 1175–1187.

    • Crossref
    • Export Citation
  • Ignatov, A. M., L. L. Stowe, S. M. Sakerin, and G. K. Korotaev, 1995: Validation of the NOAA/NESDIS satellite aerosol product over the North Atlantic in 1989. J. Geophys. Res.,100, 5123–5132.

    • Crossref
    • Export Citation
  • Inn, E., and Y. Tanaka, 1953: Absorption coefficient of ozone in the ultraviolet and visible regions. J. Opt. Soc. Amer.,43, 870–873.

    • Crossref
    • Export Citation
  • Kaufman, Y. J., and B. N. Holben, 1993: Calibration of the AVHRR visible and near-IR bands by atmospheric scattering, ocean glint and desert reflection. Int. J. Remote Sens.,14, 21–52.

    • Crossref
    • Export Citation
  • Kidwell, K. B., 1995: NOAA polar orbiter data users guide. National Climatic Data Center, Satellite Data Services Division, 200 pp. [Available from NOAA/NESDIS, National Climate Data Center, Satellite Data Services Division, Princeton Executive Square, Room 100, Washington, DC 20233.].

  • Kiehl, J. T., and B. P. Briegleb, 1993: The relative roles of sulfate aerosols and greenhouse gases in climate forcing. Science,260, 311–314.

    • Crossref
    • Export Citation
  • Koepke, P., 1984: Effective reflectance of oceanic whitecaps. Appl. Opt.,23, 1816–1824.

    • Crossref
    • Export Citation
  • Langner, J., and H. Rodhe, 1991: A global three-dimensional model of the tropospheric sulfur cycle. J. Atmos. Chem.,13, 225–263.

    • Crossref
    • Export Citation
  • ———, and Coauthors, 1993: The global atmospheric sulfur cycle: An evaluation of model predictions and observations. Rep. CM-81, 28 pp. [Available from Department of Meteorology, Stockholm University, Arrhenius Laboratory, S-106 91 Stockholm, Sweden.].

  • Morel, A., and L. Prieur, 1977: Analysis of variations in ocean color. Limnol. Oceanogr.,22, 709–722.

    • Crossref
    • Export Citation
  • Nemesure, S., R. Wagener, and S. E. Schwartz, 1995: Direct shortwave forcing of climate by anthropogenic sulfate aerosol: Sensitivity to particle size, composition, and relative humidity. J. Geophys. Res.,100, 26 105–26 116.

    • Crossref
    • Export Citation
  • Penner, J. E., and Coauthors, 1994: Quantifying and minimizing uncertainty of climate forcing by anthropogenic aerosols. Bull. Amer. Meteor. Soc.,75, 375–400.

    • Crossref
    • Export Citation
  • Rao, C. R. N., 1987: Pre-launch calibration of channels 1 and 2 of the Advanced Very High Resolution Radiometer. NOAA Tech. Rep. NESDIS 36, 62 pp. [Available from NOAA/NESDIS Satellite Research Laboratory, Washington, DC 20233.].

  • ———, L. L. Stowe, and E. P. McClain, 1989: Remote sensing of aerosols over the oceans using AVHRR data: Theory, practice, and applications. Int. J. Remote Sens.,10, 743–749.

  • ———, J. Chen, F. Staylor, P. Abel, Y. Kaufman, E. Vermote, W. Rossow, and C. Brest, 1993: Degradation of the visible and near-infrared channels of the Advanced Very High Resolution Radiometer on the NOAA-9 spacecraft: Assessment and recommendations for corrections. NOAA Tech. Rep. NESDIS 70, 62 pp. [Available from NOAA/NESDIS Satellite Research Laboratory, Washington, DC 20233.].

  • Schwartz, S. E., 1996: The Whitehouse effect—Shortwave radiative forcing of climate by anthropogenic aerosols: An overview. J. Aerosol Sci.,27, 359–382.

    • Crossref
    • Export Citation
  • Stowe, L. L., R. M. Carey, and P. P. Pellegrino, 1992: Monitoring the Mt. Pinatubo aerosol layer with NOAA 11 AVHRR data. Geophys. Res. Lett.,19, 159–162.

    • Crossref
    • Export Citation
  • Taylor, K. E., and J. E. Penner, 1994: Climate system response to aerosols and greenhouse gases: A model study. Nature,369, 734–737.

    • Crossref
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 693 393 3
PDF Downloads 115 36 5