Light-absorbing particles (LAPs) deposited on snow can
decrease snow albedo and affect climate through snow-albedo radiative
forcing. In this study, we use MODIS observations combined with a snow-albedo model (SNICAR – Snow,
Ice, and Aerosol Radiative) and a radiative transfer model (SBDART – Santa Barbara
DISORT Atmospheric Radiative Transfer) to retrieve
the instantaneous spectrally integrated radiative forcing at the surface by
LAPs in snow () under
clear-sky conditions at the time of MODIS Aqua overpass across northeastern
China (NEC) in January–February from 2003 to 2017.
presents distinct spatial
variability, with the minimum (22.3 W m−2) in western NEC and the
maximum (64.6 W m−2) near industrial areas in central NEC. The regional
mean is W m−2 in NEC. The positive (negative) uncertainties of
retrieved due to
atmospheric correction range from 14 % to 57 % (−14 % to −47 %), and
the uncertainty value basically decreases with the increased
. We attribute the
variations of radiative forcing based on remote sensing and find that the
spatial variance of in NEC
is 74.6 % due to LAPs and 21.2 % and 4.2 % due to snow grain size
and solar zenith angle. Furthermore, based on multiple linear regression,
the BC dry and wet deposition and snowfall could explain 84 % of
the spatial variance of LAP contents, which confirms the reasonability of
the spatial patterns of retrieved
in NEC. We validate
using in situ radiative
forcing estimates. We find that the biases in
are negatively correlated
with LAP concentrations and range from ∼5 % to
∼350 % in NEC.