Sensitivity studies and comprehensive evaluation of RegCM4.6.1 high-resolution climate simulations over the Tibetan Plateau

摘要: This study provides the first comprehensive assessment of Regional Climate Model version 4.6.1 (RegCM4) for Tibetan Plateau (TP) region. A wide range model configurations were analyzed with different parameterizations employed to represent cumulus convection (Kuo, Grell, Emanuel, Kain, and Tiedtke), land surface processes (BATS CLM), planetary boundary layer turbulence (Holtslag UW PBL), radiation (CCM3 RRTM). In addition above experiments at a 30-km horizontal resolution, another experiment was conducted based upon use double-nested dynamic downscaling method construct simulation 10-km resolution sensitivity resolution. We evaluated 20-year precipitation, cloud cover, budget, 2-m air temperature, atmospheric circulation against ground satellite-based observations during period 1989–2008. Among factors regarding sensitivity, precipitation unsurprisingly found be sensitive parameterization scheme, CLM is reduce rainfall compared BATS, which satisfactory both Emanuel Tiedtke schemes. Compared schemes, cover budget are surface, PBL, Generally, characterized by reduced mean enhanced longwave shortwave BATS. Conversely, PBL RRTM schemes result in increased less default options RegCM4. All experiments, except those employing Kuo temperature regional patterns reasonably well. At basin scale, seasonal cycle interannual variations not well depicted most configurations, although field reproduced. Considering all variables collectively, scheme combined demonstrated provide best performance over TP. However, higher-resolution improves significantly, particularly Brahmaputra river basin, located north Himalayas.