Journal Article

PreJuSER-4708

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Regional representativity of AERONET observation sites during the biomass burning season in South America determined by correlation studies with MODIS Aerosol Optical Depth

Hoelzemann, J. J. ; Longo, K. M. ; Fonseca, R. M. ; do Rosario, N. M. E. ; Elbern, H.FZJ* ; Feitas, S. R. ; Pires, C.

2009
Union Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/20439  doi:10.1029/2008JD010369

Abstract: This paper presents an analysis of ground-based Aerosol Optical Depth (AOD) observations by the Aerosol Robotic Network (AERONET) in South America from 2001 to 2007 in comparison with the satellite AOD product of Moderate Resolution Imaging Spectroradiometer (MODIS), aboard TERRA and AQUA satellites. Data of 12 observation sites were used with primary interest in AERONET sites located in or downwind of areas with high biomass burning activity and with measurements available for the full time range. Fires cause the predominant carbonaceous aerosol emission signal during the dry season in South America and are therefore a special focus of this study. Interannual and seasonal behavior of the observed AOD at different sites were investigated, showing clear differences between purely fire and urban influenced sites. An intercomparison of AERONET and MODIS AOD annual correlations revealed that neither an interannual long-term trend may be observed nor that correlations differ significantly owing to different overpass times of TERRA and AQUA. Individual anisotropic representativity areas for each AERONET site were derived by correlating daily AOD of each site for all years with available individual MODIS AOD pixels gridded to 1 degrees x 1 degrees. Results showed that for many sites a good AOD correlation (R-2 > 0.5) persists for large, often strongly anisotropic, areas. The climatological areas of common regional aerosol regimes often extend over several hundreds of kilometers, sometimes far across national boundaries. As a practical application, these strongly inhomogeneous and anisotropic areas of influence are being implemented in the tropospheric aerosol data assimilation system of the Coupled Chemistry-Aerosol-Tracer Transport Model coupled to the Brazilian Regional Atmospheric Modeling System (CCATT-BRAMS) at the Brazilian National Institute for Space Research (INPE). This new information promises an improved exploitation of local site sampling and, thus, chemical weather forecast.

Keyword(s): J

Note: Judith Hoelzemann is funded by the Brazilian "Fundacao de Amparo a Pesquisa do Estado de Sao Paulo'' (FAPESP) under grant 05/60890-3. This work was carried out with support by FAPESP project (2008/06822-4) and the InterAmerican Institute for Global Change Research (IAI) CRN II 2017, supported by the U.S. National Science Foundation ( grant GEO-0452325). We thank the AERONET principal investigators Brent Holben, Paulo Artaxo, and Enio B. Pereira and their staff for establishing and maintaining the South American sites used in this investigation, the NASA/MODAPS team for providing the whole suite of MODIS collection 5 data, the NASA/MOVAS/ Giovanni team at GES DISC for provision of gridded MODIS data, and two anonymous reviewers who provided very helpful comments that contributed substantially to improve this paper.

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Research Program(s):

1. Atmosphäre und Klima (P22)

Appears in the scientific report 2009

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Database coverage:
; JCR ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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