Open AccessReview of aerosol mass scattering efficiencies from ground‐based measurements since 1990
Author(s) -
Hand J. L.,
Malm W. C.
Publication year - 2007
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 - 10.1029/2007jd008484
Subject(s) - aerosol , sulfate , environmental science , ammonium sulfate , atmospheric sciences , radiative forcing , nitrate , sea salt , ammonium nitrate , radiative transfer , particulates , single scattering albedo , range (aeronautics) , extinction (optical mineralogy) , ammonium , relative humidity , mass concentration (chemistry) , environmental chemistry , chemistry , meteorology , mineralogy , physics , materials science , optics , organic chemistry , chromatography , composite material
We performed a survey of ground‐based estimates of aerosol mass scattering efficiencies ( α sp , m 2 g −1 ) for various aerosol species and size modes from peer‐reviewed literature published since 1990. Accurate estimates of α sp are important in aerosol modules of global circulation and chemical transport models to compute radiative forcing effects of aerosols and in chemical extinction budgets used for visibility regulatory purposes. The variety of techniques used to compute α sp can be categorized into four basic methods. We separate reported α sp on the basis of the methods used to derive them and normalize estimates of α sp to a common dry relative humidity (RH, RH ≈ 0%) and mass composition basis, removing some of the variability inherent in α sp reported under different monitoring conditions. The values of α sp reviewed here represent common aerosol species and correspond to data from a variety of time periods and global locations. For the 60 studies reviewed, the average (and one standard deviation) α sp (at visible wavelengths) for fine mode dry ammonium sulfate and dry ammonium nitrate are 2.5 ± 0.6 m 2 g −1 and 2.7 ± 0.5 m 2 g −1 , respectively. The fine mode particulate organic matter α sp is 3.9 ± 1.5 m 2 g −1 . The fine mode dust α sp is 3.3 ± 0.6 m 2 g −1 and the fine mode dry sea salt α sp is 4.5 ± 0.9 m 2 g −1 . Coarse mode α sp estimates are also reported. The range of α sp may reflect differences in aerosol morphology, age, physicochemical properties and mixing state; however, this survey suggests that the type of method used to derive α sp can contribute considerably to the variability observed.