Open AccessInterannual variation of ambient aerosol characteristics on the east coast of the United States
Author(s) -
Remer Lorraine A.,
Kaufman Yoram J.,
Holben Brent N.
Publication year - 1999
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 - 10.1029/1998jd200037
Subject(s) - aerosol , sky , environmental science , atmospheric sciences , haze , effective radius , range (aeronautics) , optical depth , radius , radiometer , climatology , volume (thermodynamics) , meteorology , remote sensing , physics , geology , materials science , astrophysics , quantum mechanics , computer security , galaxy , computer science , composite material
We investigate the interannual variability of the seasonally recurring aerosol haze of the United States East Coast. The data consist of observations collected by five Sun/sky radiometer stations. We compare the data collected in 1996 in conjunction with the TARFOX experiment to similar data collected at the same locations in 1993. The regional mean optical thickness remains essentially constant in the two years. The Mount Pinatubo stratospheric mode decreases spectral dependence in 1993, especially for optical thickness below 0.20. The volume size distributions inverted from the sky measurements show an increase in accumulation mode particle size with increasing aerosol optical thickness in both years. At moderate to high optical thickness (τ 670 > 0.20) the particles in the fine particle mode, 0.1–0.6 μm radius range, from both years have the same lognormal parameters ( r m = 0.21, σ = 0.45–0.50). The volume of these particles increases linearly with τ. These size particles dominate the optical properties of the aerosol in the visible spectrum and cause remarkable interannual consistency in the aerosol optical characteristics. The 1993 and 1996 phase functions agree to within 7–10% for optical thicknesses greater than 0.2.