101
© Springer Nature Switzerland AG 2020
P. S. Goel et al. (eds.), Climate Change and the White World,
https://doi.org/10.1007/978-3-030-21679-5_8
High-Resolution Dynamic Downscaling
of Winter Climate over the Himalaya
S. C. Kar, Sarita Tiwari, and Pushp Raj Tiwari
Abstract Observed climate data are few over the inaccessible regions of the
Himalaya which limits the understanding of climate variability of this third pole.
Therefore, dynamic downscaling methods need to be employed to obtain dynamically consistent high-resolution climate information over the Himalaya. In this
study, dynamic downscaling simulations have been described that were obtained
using a regional climate model (RegCM4) and the high-resolution WRF model. The
WRF model was used to downscale observed coarse-resolution ERA-I data from
1991 to 2010. The RegCM4 used the hindcasts from a coarse resolution General
Circulation Models (GCM) from 1982 to 2009. From the Weather Research and
Forecast (WRF) model simulations, it was found that snowfall contributes to about
80% or more amount of total precipitation over the western Himalaya. Detailed
vertical structure of circulation and temperature could be deciphered using the WRF
model, especially during excess and deficit years of precipitation. Detailed examination of cloud microphysical processes shows that while the rain water confines to
only lower levels, snow has maximum magnitude among all the hydrometeors during excess precipitation years. The RegCM4 model could simulate better skill in
precipitation hindcasts than the GCM used to force it.
Keywords Himalaya · Dynamic downscaling · Climate models interannual
variability
S. C. Kar (*)
National Centre for Medium Range Weather Forecasting, Noida, India
e-mail: sckar@ncmrwf.gov.in
S. Tiwari
Geological Survey of India, Hyderabad, India
P. R. Tiwari
Centre for Atmospheric and Climate Physics, University of Hertfordshire, Hertfordshire, UK
© Springer Nature Switzerland AG 2020
P. S. Goel et al. (eds.), Climate Change and the White World,
https://doi.org/10.1007/978-3-030-21679-5_8
High-Resolution Dynamic Downscaling
of Winter Climate over the Himalaya
S. C. Kar, Sarita Tiwari, and Pushp Raj Tiwari
Abstract Observed climate data are few over the inaccessible regions of the
Himalaya which limits the understanding of climate variability of this third pole.
Therefore, dynamic downscaling methods need to be employed to obtain dynamically consistent high-resolution climate information over the Himalaya. In this
study, dynamic downscaling simulations have been described that were obtained
using a regional climate model (RegCM4) and the high-resolution WRF model. The
WRF model was used to downscale observed coarse-resolution ERA-I data from
1991 to 2010. The RegCM4 used the hindcasts from a coarse resolution General
Circulation Models (GCM) from 1982 to 2009. From the Weather Research and
Forecast (WRF) model simulations, it was found that snowfall contributes to about
80% or more amount of total precipitation over the western Himalaya. Detailed
vertical structure of circulation and temperature could be deciphered using the WRF
model, especially during excess and deficit years of precipitation. Detailed examination of cloud microphysical processes shows that while the rain water confines to
only lower levels, snow has maximum magnitude among all the hydrometeors during excess precipitation years. The RegCM4 model could simulate better skill in
precipitation hindcasts than the GCM used to force it.
Keywords Himalaya · Dynamic downscaling · Climate models interannual
variability
S. C. Kar (*)
National Centre for Medium Range Weather Forecasting, Noida, India
e-mail: sckar@ncmrwf.gov.in
S. Tiwari
Geological Survey of India, Hyderabad, India
P. R. Tiwari
Centre for Atmospheric and Climate Physics, University of Hertfordshire, Hertfordshire, UK