Low (web) Quality - BALTEX

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used in RCM. To be consistent with excessive precipitation
in the low-latitude regions in the case of the RCM runs with
CCM, the intensity of trough in China and subtropical
oceanic high is strengthened.
(a) Gc_Rs – Gs_Rs vs. Gc_Rc – Gs_Rc
Giorgi, F., and co-authors, Regional climate information-
Evaluation and projections. Chapter 10 in Climate
Change 2001: The Scientific Basis, Cambridge
University Press, Houghton et al. (Eds.), 881pp, 2001
Hong, S.-Y., and H.-L. Pan, Convective trigger function
for a mass flux cumulus parameterization scheme,
Mon. Wea. Rev., 126, 2599-2620, 1998
Juang, H.-M. H., S.-Y. Hong, and M. Kanamitsu, The
NCEP regional spectral model: An update, Bull. Amer.
Meteor. Soc.,78, 2125-2143, 1997
(b) Gs_Rc - Gs_Rs vs. Gc_Rc - Gc_Rs
Wang, Y., L. R. Leung, J. L. McGregor, D.-K. Lee, W.-C.
Wang, Y. Ding, and F. Kimura, Regional climate
modeling: Progress, Challenges, and Prospects, J.
Meteor. Soc. Japan, 82, 1599-1628, 2003
Zhang G. J., and N. A. McPhalane, Sensitivity of climate
simulations to the parameterization of cumulus
convection in the Canadian climate centre general
circulation model, Atmos-Ocean, 33, 407-446, 1995
Figure 3. Vertical profiles of the difference in
temperature (K) and relative humidity (%). Upper
panel designates the difference between Gc_Rs and
Gs_Rs (solid line) and Gc_Rc and Gs_Rc (dashed
line) and lower panel shows the the difference
between Gs_Rc and Gs_Rs (solid line) and Gc_Rc and
Gc_Rs (dashed line), respectively.
The influence of the large-scale features from the GDAS is
better seen in Fig. 3. In this figure, it is seen that the
characteristics of the differences in the vertical profiles of
temperature and moisture in the global analyses appear in
the downscaled climate. A relative warming in the middle
troposphere and cooling in the lower troposphere exist in the
case of CCM-GDAS run, as analyzed in the GDAS runs.
Moistening in the upper troposphere is also visible. These
vertical structures are distinct when the RCM employed the
different convection scheme.
4. Summary
This study explores the one of the uncertainties for regional
downscaling with the regional climate models (RCMs) of
the climate signals from the general circulation models
(GCMs); the inconsistency in physical parameterization
between GCM and RCM. The results showed that the better
large-scale data result in improved regional climate. In the
seasonal simulation framework, the dependency of the
GCM-generated large-scale conditions on the downscaled
climate is as much as the regional model physics in terms of
the large-scale forcing. The consistency in physical
parameterizations between the GCM and RCM is the one of
the factors to alleviate uncertainties in regional downscaling.
References
Annamalai, H., J. M. Slingo, K. R. Sperber, and K. Hodges,
The mean evolution and variability of the Asian summer
monsoon: Comparison of ECMWF and NCEP-NCAR
reanalysis, Mon. Wea. Rev., 127, 1157-1186, 1999