Open AccessRetrieval of Pinatubo aerosol optical depth and surface bidirectional reflectance from six years of AVHRR global vegetation index data over boreal forests
Author(s) -
Molineaux Benoît,
Royer Alain,
O'Neill Norm
Publication year - 1998
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97jd02940
Subject(s) - sun photometer , aerosol , environmental science , taiga , remote sensing , radiative transfer , atmospheric correction , vegetation (pathology) , atmospheric sciences , reflectivity , meteorology , geology , geography , physics , optics , medicine , pathology , forestry
Six years (1989–1994) of weekly composite satellite data are analyzed with the objective of retrieving the aerosol optical depth over boreal forests. The average surface bidirectional reflectance distribution (BRD) was estimated from a sample of the original data, yielding similar results in different regions around the world. Four analytical models are compared in their ability to reproduce the surface BRD. In channel 1 (0.58–0.68 μm) the surface reflectance averages 0.05 and exceeds 0.10 in the backscattering region. Thus the non‐Lambertian ground contribution could not be neglected in the aerosol retrievals. A relevant radiative transfer code was run in iterative mode to retrieve the aerosol optical depth which best accounts for the difference between modeled surface BRD and measured satellite reflectance in all conditions. From comparisons with Sun photometer data we conclude that a large‐scale, persistent aerosol enhancement such as that resulting from Mount Pinatubo's eruption in 1991 is clearly discernible from weekly composite AVHRR data over boreal forests.