American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 2408864 bytes)    Cited by

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, D01201, doi:10.1029/2004JD005178, 2005

Absorbing Aerosol Index: Sensitivity analysis, application to GOME and comparison with TOMS

M. de Graaf

Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands


P. Stammes

Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands


O. Torres

NASA Goddard Space Flight Center, Greenbelt, Maryland, USA


R. B. A. Koelemeijer

National Institute of Public Health and the Environment (RIVM), Bilthoven, Netherlands


Abstract

The Absorbing Aerosol Index (AAI) was investigated and used to analyze GOME data and compare it to TOMS data. The physical interpretation of the AAI was studied with an extensive theoretical sensitivity analysis. The dependence of the method on a number of atmospheric, surface, and aerosol properties was studied using a numerical radiative transfer model. It was found to be sensitive to absorbing aerosols with wavelength-dependent refractive indices and to elevated absorbing aerosols, both with wavelength-dependent and wavelength-independent (gray) refractive indices. It was found to be insensitive to clouds, while small size scattering aerosols yield negative values. AAIs were calculated from GOME data for the period July 1995 to December 2000 and compared to TOMS AAI data. In a part of this period, July 1995 to October 1996, no TOMS observations were available, and the GOME data can be used to supplement the TOMS data set. The GOME AAI corresponds very well with known absorbing aerosol events. It suffers from lower spatial resolution and less frequent temporal coverage as compared to TOMS, but is useful as an independent data source of global aerosol measurements.

Received 30 June 2004; accepted 26 November 2004; published 14 January 2005.

Keywords: aerosols; remote sensing; AAI.

Index Terms: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906); 0394 Atmospheric Composition and Structure: Instruments and techniques; 3360 Atmospheric Processes: Remote sensing.

Read Full Article (file size: 2408864 bytes)    Cited by

Citation: de Graaf, M., P. Stammes, O. Torres, and R. B. A. Koelemeijer (2005), Absorbing Aerosol Index: Sensitivity analysis, application to GOME and comparison with TOMS, J. Geophys. Res., 110, D01201, doi:10.1029/2004JD005178.