Gadgil, S. and A. Raju, 1995: Simulation of monsoon and
its interannual variation in the AMIP runs (Diagnostic Subproject 26).
Abstracts of the First International AMIP Scientific Conference, Monterey,
California, 66.
A comparison of the simulated mean monthly precipitation
by the different models over the South Asian longitudes 70-90°E and
the African summer monsoon zone of 0-40°E with the OLR and HRC shows
that almost all the models simulate the convection over 0-30°E during
the boreal summer reasonably well and have excess precipitation at 40°E
throughout the year. For the S. Asian longitudes, six models simulate reasonably
realistically location and intensity of the summer rainbelt over the S.
Asian continent as well as the length of the rainy season. Comparison of
the variation of the simulated precipitation during the contrasting years
of 1982 and 1983 with the observed variation of OLR and Indian rainfall
shows that there appears to be no relationship between the ability to capture
the interannual variation and ability to simulate the mean precipitation
pattern. In fact, the anomalies over the Indian region for several models
appear to be of the wrong sign - so models are simulating an excess during
drought years.
Some interesting results have emerged about the pattern of anomalies.
The difference in precipitation between the two years suggest that, in
the models, the most common patterns of variation over the Indian region
are north-south shifts of the rainbelt, and also shrinking and expansion
along the east-west direction in the monsoon zone. A comparison with the
observed rainfall anomaly patterns over the Indian region provides useful
insight into the behavior of the different models.