East Asia and Western Pacific METEOROLOGY AND CLIMATE

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is not clear in the tropics. This was understood by the general climatology of
that regions (Critchfield, 1983). The surface budget is in an equilibrium. The
structure also indicates the tropical atmosphere absorbed more energy than it
radiated out through the longwave part. This excess heat has to be transported
poleward dynamically to balance the heat loss there.
Figure 7 shows some quantities in the tropics for January and July with
respect to clear and cloudy atmosphere. The characteristics in tropics for the
clear and cloudy atmosphere are quite similar as those shown for the global mean.
This resemblance is a simple reflection that the tropical regions contribute a great
extent of the global mean. The tropical atmosphere has about 10% heat excess
(around 35 w/m 2 ) to be transported to the higher latitudes.
For higher latitudes regions, the results are not shown here. Their characteristics
are that net atmospheric cooling exists in January, in contrast to the heating
in July. This winter cooling is balanced to some extent by the heat transported
from lower latitudes.
4. SUMMARY
This study used the simulated data from OSU GCM to investigate the earthatmosphere's
radiation budget. The physical processes related to this study are
the shortwave (longwave) fluxes in the earth's surface and within the atmosphere,
along with the surface latent and sensible heat fluxes. These processes are identified
and used to construct the budget , also are compared with the observed
climatology. In annual mean sense, the simulated budget is reasonably good. For
the shortwave part, the simulated planetary albedo is overestimated by about 7%,
the atmospheric absorption is underestimated by 6%.
The surface absorption of shortwave, surface latent and sensible fluxes and
surface outgoing longwave radiation are quite close to the observed. The simulated
net longwave atmospheric cooling is short of 7%, compared with the observed
value. Seasonal variation of the atmospheric absorption of shortwave fluxes is
quite small. Clouds are found to affect the surface budget greatly, however, their
influence in the atmospheric absorption in annual mean sense is small.
Regional characteristics indicates that the tropical atmosphere has about 10%
heat excess to be transported to the higher latitudes. Seasonal reversal is obvious
in the higher latitudes for some processes, but not the atmospheric absorption of
the shortwave fluxes. In polar region, the surface fluxes are found to be quite small
in the summer hemisphere. For the winter hemisphere, the fluxes in that regions