Marine Ecosystems Research Department - jamstec japan agency ...

JAMSTEC 2002 Annual Report
Frontier Research System for Global Change
reduced by the frozen soil permeability and is
enhanced by the surface storage (see Figure ).
The effects of the land-surface process on the Asian
continent were estimated by data analysis and by
numerical models. We found that the land surface heating
in Siberia affects the activity of the Okhotsk high,
which often bring us cold summers. By data analysis,
the relation between the land surface in Siberia and the
Okhotsk high are speculated as follows: () A poleward
warm and moist air advection appears in the
lower troposphere induced by the heat contrast
between the continent and Okhotsk Sea. () The warm
and moist poleward wind increases convection instability
around East Siberia and then cumulus convection
appears there. () Latent heat released by the cumulus
m
m
m
0.5
1
1.5
2
2.5
Soil moisture and flux at Khabarovsk
P run
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1982
0.5
1
1.5
2
2.5
PI run
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1982
0.5
1
1.5
2
2.5
PID run
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1982
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45
Fig. 6 Time-depth cross section of daily volumetric soil moisture
content (color tones) and soil moisture fluxes (arrows) at
Khabarovsk. Upper panel: without soil moisture flux, without
surface water storage, Middle panel: Same as the
upper panel except for with ice dependent permeability of
frozen ground, Bottom panel: Same as the middle panel,
except for with surface water storage.
convection deforms the large scale atmospheric circulation
and forms an anti-cyclonic circulation around
the convective region. () The upper tropospheric ridge
is formed by the interaction between the anti-cyclonic
circulation and the westerly. () Then, the Okhotsk
high is intensified by an equatorward flow located east
of the ridge in the upper troposphere.
c. Clouds and Precipitation Process Group
c-. Improvement of Parameterization Schemes of
Microphysics and Radiative Properties of Clouds
We proposed a new method to predict the optical
thickness, effective radius, and concentration of cloud
droplets in water layer clouds by using the spectrum of
cloud condensation nuclei (CCN), ascent velocity at
cloud base, and liquid water path (LWP) (Kuba et al.,
). A retrieval method is also proposed to predict
CCN number concentration by using independent observational
data of ascent velocity at the cloud base, the
optical thickness and LWP of clouds. These parameterizations
are derived from a large number of numerical
simulations using a newly developed cloud microphysical
model. Then, Kuba and Iwabuchi () improved
the approximation for convenience. In addition, this
study proposes an approximation for higher updraft
velocities than those in the previous paper (Figure ).
A multi-spectral non-local (MSN) method to
retrieve boundary layer cloud physical quantities from
optical remote sensing data is examined as an alternative
to the conventional independent pixel approximation
(IPA) retrieval method. The radiance data to be
observed from space were simulated by using a threedimensional
radiation model and stochastic boundary
layer cloud model with horizontal and vertical inhomogeneity
of cloud liquid water and effective radius.
It is demonstrated that with MSN method, the error
can be reduced to about -%. A generalization ability
of MSN method was examined, and a high performance
is demonstrated, not highly depending on
assumptions in inhomogeneous cloud models.
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