%0 Journal Article
%T Validation of the HIRHAM-Simulated Indian Summer Monsoon Circulation
%A Stefan Polanski
%A Annette Rinke
%A Klaus Dethloff
%J Advances in Meteorology
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/415632
%X The regional climate model HIRHAM has been applied over the Asian continent to simulate the Indian monsoon circulation under present-day conditions. The model is driven at the lateral and lower boundaries by European reanalysis (ERA40) data for the period from 1958 to 2001. Simulations with a horizontal resolution of 50£¿km are carried out to analyze the regional monsoon patterns. The focus in this paper is on the validation of the long-term summer monsoon climatology and its variability concerning circulation, temperature, and precipitation. Additionally, the monsoonal behavior in simulations for wet and dry years has been investigated and compared against several observational data sets. The results successfully reproduce the observations due to a realistic reproduction of topographic features. The simulated precipitation shows a better agreement with a high-resolution gridded precipitation data set over the central land areas of India and in the higher elevated Tibetan and Himalayan regions than ERA40. 1. Introduction The Asian monsoon circulation is characterized by variability on seasonal, interannual, and interdecadal time scales and impacts on water availability in a highly populated region with dominating agriculture. For this reason, the understanding of the complex mechanisms and interactions between the atmospheric patterns affecting the entire monsoon system is of special interest. Global general circulation models (GCMs) are often used to simulate the large-scale circulation of the monsoon (e.g., [1¨C3]). Regional Climate Model (RCM) systems with higher spatial and temporal resolutions can add value at regional scales to the climate statistics when driven by GCMs with accurate large scales. Therefore, RCMs nested in a GCM or driven by data analyses have been applied for a special area of interest by dynamical downscaling and to improve their performance (e.g., [4, 5]). Several RCM simulations have been carried out for the South Asian Monsoon region (e.g., [6¨C13]). In this study, we apply the regional climate model HIRHAM on an Asian integration domain and analyze a 44-year-long simulation 1958¨C2001 driven by ECMWF reanalysis (ERA40 data). The HIRHAM model is one state-of-the-art RCM and has been already successfully applied for European regions (e.g., [14, 15]), for the Arctic (e.g., [16¨C18]) as well as for Antarctica (e.g., [19, 20]). HIRHAM has been integrated over the Asian continent covering the high topography of Himalayas and Tibetan Plateau to simulate the Indian monsoon under present-day conditions. Before the model can be applied to
%U http://www.hindawi.com/journals/amete/2010/415632/