چكيده لاتين :
This paper qualifies the impact of different convection schemes and domain
centers on the simulation of two dry and wet winter precipitations of 1997 and
2000 over Iran using RegCM3 numerical climate model. The model uses a
compressible, finite difference with hydrostatic equilibrium in sigma coordinate
and a semi-implicit algorithm for reduction of horizontal diffzLsion. In this
st>ndy, sensitwity of the RegCM3 regional climate model has been analyzed
using different convection schemes, including Greli-AיS, Grell- FC, Emanuel
and K uo schemes and different domain center locations including Himalaya,
Mediterranean sea, han and Indian ocean (near Pakistan southern border).
NNRPJ data with a 5-degree resoluiion.os well as GLCC and GTOPO dataset
are used as initial and boundary conditions. land use and topography data,
respectively.
We found that the perjorttuince of the Model strongly depends on the
location of the domain center, for example when the center of the domain
is located over Himalaya then the results for the precipitation are reasonobls;
better especially when a Siberian high pressure develops over Iran. With
K1W scheme.the minimum of bias and MAE are -0.7mm and 0.6mm for dry
year of 2000, but with Grell scheme the error is found to be a minimum
compared to other configurations of the model both in dry and wet seasons. In
all experiments the precipitation amounts arc underestimated when compared
to corresponding observations. The largest difference occurred in Himolau«
experiment. Moreovcr, we found that there is an eastward shift in Caspian Sea
precipitation patt.ern. in all experiments.
It is also found that CRU reanalysis data cannot be considered as a
reference for calibration of RegCM3 over Iran.
