Geoscience Reference
In-Depth Information
Fig. 5. Evolutionary features of the spatial distribution of direct radiative forcing
(W/m
2
) at the surface due to both Asian dust and anthropogenic aerosols.
transported down wind and merge together with the anthropogenic aerosol
originating from eastern China where anthropogenic emissions of pollutants
are maximum. This results in a high concentration of aerosols over the East
China Sea, Korea, and Japan. Consequently, the direct radiative forcing at
the surface is greater than -20 W/m
2
in these regions on March 22, 2002
(Fig. 5). Similar evolutionary features of observed aerosol index produced
by the Total Ozone Mapping Spectrometer (TOMS) are evident during the
analysis period (not shown here).
Furthermore, similar evolutionary features of the direct radiative forcing
at TOA are evident in Fig. 6. In the early stage of the dust storm develop-
ment in northern central China on March 19 the maximum radiative forcing
at TOA associated with the dust storm is separated from that associated
with transformed aerosols from anthropogenic pollutants that have their
maximum emissions in East China. Gradually, both the Asian dust aerosol
and the anthropogenic aerosol are transported eastward to merge together
