Comparison of Recent European Climate Trends and Extremes with RegCM3 Future Projections
Effect of Tibetan snow on Indian Summer monsoon rainfall using RegCM3
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Transcript of Effect of Tibetan snow on Indian Summer monsoon rainfall using RegCM3
Effect of Tibetan snow on Indian Summer monsoon rainfall using
RegCM3
M. S. Shekhar (India)
B. R. S. B. Basnayake (Sri Lanka)
A. U. Ahmed (Bangladesh)
Group-16
Workshop on Theory and use of Regional Climate Model (RegCM3)
Introduction
The summer monsoon of southwest Asia is the largest anomaly of general circulation
Interannual variations of summer monsoon rainfall affects agriculture, water resources and the economy of the country.
The slowly varying boundary conditions at the surface of earth provides required memory in the climate
system to predict averaged monsoon circulation and rainfall.
There exist an inverse relationship between Indian summer monsoon rainfall and the extent of Eurasian snow cover in the preceding season.
Objectives
To simulate Indian summer monsoon circulation features and Rainfall over the Indian region using NCEP/NCAR reanalysed data in RegCM3.
To conduct sensitivity experiments by using snow depth over Tibet to study its effect on
Indian summer monsoon rainfall.
Domain Information
Central Latitude- 20oN Central Longitude- 80
oE
57 X 51 Points
50oE to 105
oE 5
oS to 45
oN
Grid distance- 110 Km
Data used
10’ USGS elevation data.
GLCC Landuse data.
OI SST
NCEP Reanalysis data-II
June 1994 July 1994
KUO
Rainfall (mm/day)
June 1994 July 1994GRELL
No snow 0.5 m. snow
June 1994
No snow 0.5 m. snow
July 1994
ConclusionsThe Regional Climate Model (RegCM3) is able to simulate the monsoon circulation over India reasonably well.
The rainfall simulated in mm/day in Grell convection scheme is closer to the observed rainfall of the India Meteorological Department compared to the Kuo.
The inverse snow-ISMR relationship is confirmed by using snow depth as the boundary condition in RegCM3.
The All India rainfall is reduced by almost 20-25% in the high Tibetan snow experiment than in the control experiment.