Zhang, Y., K. R. Sperber, J. S. Boyle, M. Dix, L. Ferranti, A. Kitoh,
K. M. Lau, K. Miyakoda, D. Randall, L. Takacs, and R. Wetherald, 1997:
East Asian winter monsoon: results from eight AMIP models. Climate
Dynamics, 13(11), 797-820.
Abstract: This study evaluates simulations of the East Asian winter
monsoon in eight GCMs that participated in the Atmospheric Model Intercomparison
Project (AMIP). In addition to validating the mean state of the winter
monsoon, the cold surge and its transient properties, which includes the
frequency, intensity, preferred propagation tracks, and the evolution patterns
of the surges, are examined. GCM simulated temporal distribution of the
Siberian high and cold surges is also discussed. Finally, the forcing of
the cold surges on the tropical surface wind and convection, along with
their interannual variation is analyzed. The mean state of the winter monsoon
is generally portrayed well in most of the models. These include the climatological
position of the Siberian high, the 200 hPa divergent center, and the large-scale
wind patterns at the surface and the 200 hPa. Models display a wide range
of skill in simulating the cold surge and its transient properties. In
some of the models, the simulated cold surge trajectory, intensity, frequency,
propagation patterns and source regions are in general agreement with those
from the observed while in others, the models cannot adequately capture
these observed characteristics. The temporal distribution of the Siberian
high and cold surges were realistically reproduced in most GCMs. Most models
were able to simulate the effect of the cold surges on the tropical surface
wind, although a few models unrealistically generated subtropical southerly
wind in the mid-winter. The relationship between cold surges and the tropical
convection was not satisfactorily simulated in most models. The common
discrepancies in the winter monsoon simulation can be attributed to many
factors. In some models, the reason is directly related to the improper
location of the large-scale convective center near the western Pacific.
The satisfactory simulations of the monsoon circulation and the cold surges
are partly due to the topographical characteristics of the East Asian continent,
i.e., the Tibetan Plateau to the west and the oceans to the east. The correct
simulation of the internnual variation of the surface wind near the South
China Sea (SCS) and the maritime continent is a demanding task for most
of the models. This will require adequate simulations of many aspects,
including tropical convection, the Siberian cold dome, the extratropical-tropical
linkage, and the air-sea interaction. The discrepancies noted here furnish
a guide for the continuing improvement of the winter monsoon simulations.
Improved simulations will lead to an adequate delineation of the surface
wind and convection near the maritime continent, which is essential for
portraying the winter monsoon forcing in a coupled model.