Improving satellite-retrieved aerosol microphysical properties using GOCART data
The Multi-angle Imaging SpectroRadiometer (MISR) aboard the NASA Earth Observing System's Terra satellite can provide more reliable aerosol optical depth (AOD) and better constraints on particle size (Ångström exponent, or ANG), sphericity, and single-scattering albedo (SSA) than many other sat...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2015-03-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/8/1157/2015/amt-8-1157-2015.pdf |
| _version_ | 1828805954210103296 |
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| author | S. Li R. Kahn M. Chin M. J. Garay Y. Liu |
| author_facet | S. Li R. Kahn M. Chin M. J. Garay Y. Liu |
| author_sort | S. Li |
| collection | DOAJ |
| description | The Multi-angle Imaging SpectroRadiometer (MISR) aboard
the NASA Earth Observing System's Terra satellite can provide more reliable
aerosol optical depth (AOD) and better constraints on particle size
(Ångström exponent, or ANG), sphericity, and single-scattering albedo (SSA) than many other satellite instruments. However, many aerosol mixtures
pass the algorithm acceptance criteria, yielding a poor constraint, when the
particle-type information in the MISR radiances is low, typically at low
AOD. We investigate adding value to the MISR aerosol product under these
conditions by filtering the list of MISR-retrieved mixtures based on
agreement between the mixture ANG and absorbing AOD (AAOD) values, and
simulated aerosol properties from the Goddard Chemistry Aerosol Radiation
and Transport (GOCART) model. MISR–GOCART ANG difference and AAOD ratio
thresholds for applying GOCART constraints were determined based on
coincident AOD, ANG, and AAOD measurements from the AErosol RObotic NETwork (AERONET). The results were validated by comparing the adjusted MISR aerosol
optical properties over the contiguous USA between 2006 and 2009 with
additional AERONET data. The correlation coefficient (<i>r</i>) between the
adjusted MISR ANG derived from this study and AERONET improves to 0.45,
compared to 0.29 for the MISR Version 22 standard product. The ratio of the
adjusted MISR AAOD to AERONET increases to 0.74, compared to 0.5 for the
MISR operational retrieval. These improvements occur primarily when
AOD < 0.2 for ANG and AOD < 0.5 for AAOD. Spatial and temporal
differences among the aerosol optical properties of MISR V22, GOCART, and
the adjusted MISR are traced to (1) GOCART underestimation of AOD and ANG in
polluted regions; (2) aerosol mixtures lacking in the MISR Version 22
algorithm climatology; (3) low MISR sensitivity to particle type under some
conditions; and (4) parameters and thresholds used in our method. |
| first_indexed | 2024-12-12T08:02:34Z |
| format | Article |
| id | doaj.art-b492ab28813c40fabe7b000aecc98b59 |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-12-12T08:02:34Z |
| publishDate | 2015-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-b492ab28813c40fabe7b000aecc98b592022-12-22T00:32:05ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482015-03-01831157117110.5194/amt-8-1157-2015Improving satellite-retrieved aerosol microphysical properties using GOCART dataS. Li0R. Kahn1M. Chin2M. J. Garay3Y. Liu4Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USALaboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland, USALaboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland, USAJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USADepartment of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USAThe Multi-angle Imaging SpectroRadiometer (MISR) aboard the NASA Earth Observing System's Terra satellite can provide more reliable aerosol optical depth (AOD) and better constraints on particle size (Ångström exponent, or ANG), sphericity, and single-scattering albedo (SSA) than many other satellite instruments. However, many aerosol mixtures pass the algorithm acceptance criteria, yielding a poor constraint, when the particle-type information in the MISR radiances is low, typically at low AOD. We investigate adding value to the MISR aerosol product under these conditions by filtering the list of MISR-retrieved mixtures based on agreement between the mixture ANG and absorbing AOD (AAOD) values, and simulated aerosol properties from the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model. MISR–GOCART ANG difference and AAOD ratio thresholds for applying GOCART constraints were determined based on coincident AOD, ANG, and AAOD measurements from the AErosol RObotic NETwork (AERONET). The results were validated by comparing the adjusted MISR aerosol optical properties over the contiguous USA between 2006 and 2009 with additional AERONET data. The correlation coefficient (<i>r</i>) between the adjusted MISR ANG derived from this study and AERONET improves to 0.45, compared to 0.29 for the MISR Version 22 standard product. The ratio of the adjusted MISR AAOD to AERONET increases to 0.74, compared to 0.5 for the MISR operational retrieval. These improvements occur primarily when AOD < 0.2 for ANG and AOD < 0.5 for AAOD. Spatial and temporal differences among the aerosol optical properties of MISR V22, GOCART, and the adjusted MISR are traced to (1) GOCART underestimation of AOD and ANG in polluted regions; (2) aerosol mixtures lacking in the MISR Version 22 algorithm climatology; (3) low MISR sensitivity to particle type under some conditions; and (4) parameters and thresholds used in our method.http://www.atmos-meas-tech.net/8/1157/2015/amt-8-1157-2015.pdf |
| spellingShingle | S. Li R. Kahn M. Chin M. J. Garay Y. Liu Improving satellite-retrieved aerosol microphysical properties using GOCART data Atmospheric Measurement Techniques |
| title | Improving satellite-retrieved aerosol microphysical properties using GOCART data |
| title_full | Improving satellite-retrieved aerosol microphysical properties using GOCART data |
| title_fullStr | Improving satellite-retrieved aerosol microphysical properties using GOCART data |
| title_full_unstemmed | Improving satellite-retrieved aerosol microphysical properties using GOCART data |
| title_short | Improving satellite-retrieved aerosol microphysical properties using GOCART data |
| title_sort | improving satellite retrieved aerosol microphysical properties using gocart data |
| url | http://www.atmos-meas-tech.net/8/1157/2015/amt-8-1157-2015.pdf |
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