How robust and (un)certain are regional climate models over the Himalayas?

Abstract

Regional Climate Model(s) (RCMs) are sensitive towards presentation of regional cli- mate of Indian winter monsoon (IWM) over the western Himalayas (WH). They illustrate robust nature in representing regional climate at mountain scale and even at event 5 scale. While downscaling outputs, from these models, at basin level for hydrological and glaciological studies, it is found that RCMs fail to provide realistic figures. And hence, in the present paper, using the Siachen glacier basin as a reference, debate and deliberation on RCMs’ uncertainly and high order of deviation from real obser- vations is presented. Results from RCMs thus need “further tuning” if they are used 10 for hydrological and glacier studies. Reasons for such uncertainties could be due to the improper representation of topography, missing subgrid scale processes, surface flux characteristics, various physical processes etc. at such finer model resolution and scale. At present, this paper only deliberates and brings out issues pertaining to such complexities to provide an insight for future course of studies, if understood correctly.