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aerosol (3 W/m
2
) is larger that due to the anthropogenic aerosol (2 W/m
2
)
for this period.
4. Summary and Conclusions
An intense Hwangsa event has been observed in Korea on March 19-23,
2002. The ADAM model and the aerosol dynamic model using the output
of the MM5 meteorological model on a horizontal grid of 30
30 km
2
have
been employed to simulate the temporal and spatial distribution of the
Asian Dust aerosol and the anthropogenic aerosol concentration in East
Asia during this period. The simulated both aerosols are implemented to
estimate direct radiative forcing at the surface (SRF) and the TOA using
the CRM model of NCAR.
The results indicate that the daily mean radiative forcing at the surface
and at the top of atmosphere varies according to the evolutionary features
of the dust aerosol and the anthropogenic aerosol concentrations in asso-
ciation with the development of dust storms and the emission distribution
of the anthropogenic pollutants in East Asia. The averaged total aerosol
mass in the analysis domain for the analysis period is found to be about
880 mg/m
2
. Most of the aerosol mass is composed of the Asian dust aerosol
(98%). However, the estimated mean radiative forcing values at the surface
(
×
6W
/
m
2
) by the dust aerosol
are about 60 and 55%, respectively, suggesting a larger influence by the
anthropogenic aerosol on the radiative forcing at both the surface and the
top of atmosphere, which is due to its small-size spectrum.
The difference between the radiative forcing at TOA and at the surface
indicates the atmospheric absorption due to aerosols. The estimated radia-
tive forcing due to atmospheric aerosol absorption in the analysis domain is
found to be 5 W/m
2
, of which 3 and 2 W/m
2
can be attributed to the Asian
dust aerosol and the anthropogenic aerosol, respectively. This study clearly
indicates that both Asian dust and anthropogenic aerosols cause significant
at the surface and at the top of atmosphere, particularly in downstream of
sources where the dust aerosol and anthropogenic aerosol regions overlap
each other.
11 W
/
m
2
) and at the top of atmosphere (
−
−
Acknowledgments
This research is partially supported by Climate Environment System
Research Center that is funded by Korea Science and Engineering
