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Spectral absorption properties of aerosol particles from 350–2500nm
Author(s) -
Martins J. Vanderlei,
Artaxo Paulo,
Kaufman Yoram J.,
Castanho Andrea D.,
Remer Lorraine A.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl037435
Subject(s) - aerosol , absorption (acoustics) , environmental science , atmospheric sciences , wavelength , materials science , meteorology , geography , optoelectronics , geology , composite material
The aerosol spectral absorption efficiency ( α a in m 2 /g) is measured over an extended wavelength range (350–2500 nm) using an improved calibrated and validated reflectance technique and applied to urban aerosol samples from Sao Paulo, Brazil and from a site in Virginia, Eastern US, that experiences transported urban/industrial aerosol. The average α a values (∼3m 2 /g at 550 nm) for Sao Paulo samples are 10 times larger than α a values obtained for aerosols in Virginia. Sao Paulo aerosols also show evidence of enhanced UV absorption in selected samples, probably associated with organic aerosol components. This extra UV absorption can double the absorption efficiency observed from black carbon alone, therefore reducing by up to 50% the surface UV fluxes, with important implications for climate, UV photolysis rates, and remote sensing from space.