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., [1–3]). 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., [6–13]). In this study, we apply the regional climate model HIRHAM on an Asian integration domain and analyze a 44-year-long simulation 1958–2001 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., [16–18]) 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
References
[1]
G.-S. Chen, Z. Liu, S. C. Clemens, W. L. Prell, and X. Liu, “Modeling the time-dependent response of the Asian summer monsoon to obliquity forcing in a coupled GCM: a PHASEMAP sensitivity experiment,” Climate Dynamics, 2010.
[2]
A. Dallmeyer, M. Claussen, and J. Otto, “Contribution of oceanic and vegetation feedbacks to Holocene climate change in Central and Eastern Asia,” Climate of the Past Discussions, vol. 5, no. 5, pp. 2351–2389, 2009.
[3]
N.-C. Lau and J. J. Ploshay, “Simulation of synoptic- and subsynoptic-scale phenomena associated with the East Asian summer monsoon using a high-resolution GCM,” Monthly Weather Review, vol. 137, no. 1, pp. 137–160, 2009.
[4]
C. L. Castro, R. A. Pielke Sr., and G. Leoncini, “Dynamical downscaling: assessment of value retained and added using the Regional Atmopsheric Modeling System (RAMS),” Journal of Geophysical Research D, vol. 110, no. 5, pp. 1–21, 2005.
[5]
C. L. Castro, R. A. Pielke Sr., and J. O. Adegoke, “Investigation of the summer climate of the contiguous United States and Mexico using the Regional Atmospheric Modeling System (RAMS). Part I: model climatology (1950–2002),” Journal of Climate, vol. 20, no. 15, pp. 3844–3865, 2007.
[6]
B. Bhaskaran, R. G. Jones, J. M. Murphy, and M. Noguer, “Simulations of the Indian summer monsoon using a nested regional climate model: domain size experiments,” Climate Dynamics, vol. 12, no. 9, pp. 573–587, 1996.
[7]
X. Cui, B. Langmann, and H.-F. Graf, “Summer monsoonal rainfall simulation on theT ibetan Plateau with a regional climate model using a one-way double-nesting system,” Scientific Online Letters on the Atmosphere, vol. 3, pp. 49–52, 2007.
[8]
A. Dobler and B. Ahrens, “Analysis of the Indian summer monsoon system in the regional climate model COSMO-CLM,” Journal of Geophysical Research D, vol. 115, no. 16, Article ID D16101, 2010.
[9]
C. Fu, S. Wang, Z. Xiong et al., “Regional climate model intercomparison project for Asia,” Bulletin of the American Meteorological Society, vol. 86, no. 2, pp. 257–266, 2005.
[10]
Y. Ji and A. D. Vernekar, “Simulation of the Asian summer monsoons of 1987 and 1988 with a regional model nested in a global GCM,” Journal of Climate, vol. 10, no. 8, pp. 1965–1979, 1997.
[11]
J. V. Ratnam, F. Giorgi, A. Kaginalkar, and S. Cozzini, “Simulation of the Indian monsoon using the RegCM3-ROMS regional coupled model,” Climate Dynamics, vol. 33, no. 1, pp. 119–139, 2008.
[12]
T. Sato, “Influences of subtropical jet and Tibetan Plateau on precipitation pattern in Asia: insights from regional climate modeling,” Quaternary International, vol. 194, no. 1-2, pp. 148–158, 2009.
[13]
R. Schiemann, D. Lüthi, P. L. Vidale, and C. Sch？r, “The precipitation climate of Central Asia—intercomparison of observational and numerical data sources in a remote semiarid region,” International Journal of Climatology, vol. 28, no. 3, pp. 295–314, 2008.
[14]
J. H. Christensen and O. B. Christensen, “A summary of the PRUDENCE model projections of changes in European climate by the end of this century,” Climatic Change, vol. 81, no. 1, pp. 7–30, 2007.
[15]
R. Dankers, L. Feyen, and O. B. Christensen, “On the benefit of high-resolution climate simulations in impact studies of hydrological extremes,” Hydrology and Earth System Sciences Discussions, vol. 6, pp. 2573–2597, 2009.
[16]
A. Rinke and K. Dethloff, “Simulated circum-Arctic climate changes by the end of the 21st century,” Global and Planetary Change, vol. 62, no. 1-2, pp. 173–186, 2008.
[17]
H. Matthes, A. Rinke, and K. Dethloff, “Variability of extreme temperature in the Arctic—observation and RCM,” Open Atmospheric Sciences Journal, vol. 4, pp. 126–136, 2010.
[18]
A. Rinke, H. Matthes, and K. Dethloff, “Regional characteristics of Arctic temperature variability: comparison of observations with regional climate simulations,” Climate Research, vol. 41, no. 3, pp. 177–192, 2010.
[19]
Y. Xin, A. Rinke, L. Bian, K. Dethloff, C. Xiao, and M. Mielke, “Climate and forecast mode simulations for antarctica: implications for temperature and wind,” Advances in Atmospheric Sciences, vol. 27, no. 6, pp. 1453–1472, 2010.
[20]
K. Dethloff, K. Glushak, A. Rinke, and D. Handorf, “Antarctic 20th century accumulation changes based on regional climate model simulations,” Advances in Meteorology, vol. 2010, Article ID 327172, 14 pages, 2010.
[21]
J. H. Christensen, O. B. Christensen, P. Lopez, E. van Meijgaard, and M. Botzet, “The HIRHAM4 regional atmospheric climate model,” DMI Scientific Report 96-4, Danish Meteorological Institute, Kopenhagen, Denmark, 1996.
[22]
K. Dethloff, A. Rinke, R. Lehmann, J. H. Christensen, M. Botzet, and B. Machenhauer, “Regional climate model of the Arctic atmosphere,” Journal of Geophysical Research D, vol. 101, no. 18, pp. 23401–23422, 1996.
[23]
A. Rinke, K. Dethloff, J. H. Christensen, M. Botzet, and B. Machenhauer, “Simulation and validation of Arctic radiation and clouds in a regional climate model,” Journal of Geophysical Research D, vol. 102, no. 25, pp. 29833–29847, 1997.
[24]
B. Machenhauer, “The HIRLAM final report,” HIRLAM Technical Report 5, Danish Meteorological Institute, Kopenhagen, Denmark, 1988.
[25]
E. Roeckner, K. Arpe, L. Bengtsson, et al., “The atmospheric general circulation model ECHAM-4: model description and simulation of present-day climate,” MPI Report 218, Max-Planck-Institute for Meteorology, Hamburg, Germany, 1996.
[26]
H. C. Davies, “A lateral boundary formulation for multilevel prediction models,” Quarterly Journal of the Royal Meteorological Society, vol. 102, pp. 405–418, 1976.
[27]
S. M. Uppala, P. W. K？llberg, A. J. Simmons et al., “The ERA-40 re-analysis,” Quarterly Journal of the Royal Meteorological Society, vol. 131, no. 612, pp. 2961–3012, 2005.
[28]
U. Schneider, T. Fuchs, A. Meyer-Christoffer, and B. Rudolf, “Global precipitation analysis products of the GPCC,” Tech. Rep., German Weather Service, Offenbach, Germany, 2008.
[29]
M. Rajeevan, J. Bhate, J. D. Kale, and B. Lal, “High resolution daily gridded rainfall data for the Indian region: analysis of break and active monsoon spells,” Current Science, vol. 91, no. 3, pp. 296–306, 2006.
[30]
P. D. Clift and R. A. Plumb, The Asian Monsoon: Causes, History and Effects, Cambridge University Press, Cambridge, UK, 2008.
[31]
J. Lighthill and R. P. Pearce, Monsoon Dynamics, Cambridge University Press, Cambridge, UK, 2009.
[32]
B. Wang, et al., The Asian Monsoon, Springer, Berlin, Germany, 2006.
[33]
D. Zhang, X. Gao, L. Ouyang, and W. Dong, “Simulation of present climate over East Asia by a regional climate model,” Journal of Tropical Meteorology, vol. 14, no. 1, pp. 19–23, 2008.
[34]
X. Gao, Y. Xu, Z. Zhao, J. S. Pal, and F. Giorgi, “On the role of resolution and topography in the simulation of East Asia precipitation,” Theoretical and Applied Climatology, vol. 86, no. 1–4, pp. 173–185, 2006.
[35]
B. N. Goswami and P. K. Xavier, “ENSO control on the south Asian monsoon through the length of the rainy season,” Geophysical Research Letters, vol. 32, no. 18, Article ID L18717, 4 pages, 2005.
[36]
J. D. Farrara and J.-Y. Yu, “Interannual variations in the Southwest U.S. Monsoon and sea surface temperature anomalies: a general circulation model study,” Journal of Climate, vol. 16, no. 11, pp. 1703–1720, 2003.
[37]
S. K. Dash, M. S. Shekhar, and G. P. Singh, “Simulation of Indian summer monsoon circulation and rainfall using RegCM3,” Theoretical and Applied Climatology, vol. 86, no. 1–4, pp. 161–172, 2006.
