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Spatial and Temporal Variability of Brown Carbon in the United States: Implications for Direct Radiative Effects
Author(s) -
June Nicole A.,
Wang Xuan,
Chen L.W. Antony,
Chow Judith C.,
Watson John G.,
Wang Xiaoliang,
Henderson Barron H.,
Zheng Yiqi,
Mao Jingqiu
Publication year - 2020
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 - 10.1029/2020gl090332
Subject(s) - radiative transfer , environmental science , atmospheric sciences , spatial variability , carbon fibers , climatology , remote sensing , physics , geology , materials science , statistics , mathematics , optics , composite number , composite material
A newly developed data set from the Interagency Monitoring of PROtected Visual Environments (IMPROVE) observation network, combined with a 3‐D chemical transport model, is used to evaluate the spatial and temporal variability of brown carbon (BrC) in the United States. The model with BrC emitted from biomass burning and biofuel emissions agrees with the seasonal and spatial variability of BrC planetary boundary layer (PBL) absorption aerosol optical depth (AAOD) observations within a factor of 2. The model without whitening, the tendency for absorption to decrease with aerosol aging, overestimates the observed BrC PBL AAOD and does not reflect the measured BrC PBL AAOD spatial variability. The model shows higher absorption direct radiative effects (DRE) from BrC at northern high latitudes than at midlatitudes in spring and summer, due to boreal fire emissions, long whitening lifetimes, and high surface albedos. These findings highlight the need to study BrC over the Arctic region.