107
levels up to 100 hPa. The latitudinal cross-section of the zonal winds for the two
longitudinal belts are shown in Fig. 4b, e respectively. The westerly jet is seen at
200 hPa with core around 31°N in western Himalaya and around 32°N in the eastern
Himalaya as compared to 30°N and 28°N in ERA-I. The winds are westerlies at all
the levels and zonal wind strength increases with height. Therefore, the WRF model
downscaling has moved the westerly core to north as compared to ERA-I analysis
over the Himalaya. Moreover, the zonal wind strength in the core is less in the
model simulations as compared to ERA-I Fig. 4c, f depict the sectorial average of
meridional component of wind (v) over the two belts. The role of orography is
clearly visible in the meridional winds. From 25°N to 30°N, northerly winds dominate the western Himalayan region up to about 300 hPa. To the north, southerly
winds are seen with a centre of maximum v (~3–5 m/s) over 36°N. This is where
Fig. 3 (a) The WRF model simulated snow water equivalent (SWE) climatology (mm/d) during
DJF; (b) Ratio (%) of snowfall to total precipitation
High-Resolution Dynamic Downscaling of Winter Climate over the Himalaya
levels up to 100 hPa. The latitudinal cross-section of the zonal winds for the two
longitudinal belts are shown in Fig. 4b, e respectively. The westerly jet is seen at
200 hPa with core around 31°N in western Himalaya and around 32°N in the eastern
Himalaya as compared to 30°N and 28°N in ERA-I. The winds are westerlies at all
the levels and zonal wind strength increases with height. Therefore, the WRF model
downscaling has moved the westerly core to north as compared to ERA-I analysis
over the Himalaya. Moreover, the zonal wind strength in the core is less in the
model simulations as compared to ERA-I Fig. 4c, f depict the sectorial average of
meridional component of wind (v) over the two belts. The role of orography is
clearly visible in the meridional winds. From 25°N to 30°N, northerly winds dominate the western Himalayan region up to about 300 hPa. To the north, southerly
winds are seen with a centre of maximum v (~3–5 m/s) over 36°N. This is where
Fig. 3 (a) The WRF model simulated snow water equivalent (SWE) climatology (mm/d) during
DJF; (b) Ratio (%) of snowfall to total precipitation
High-Resolution Dynamic Downscaling of Winter Climate over the Himalaya