Fidelity of Regional Climate Model v4.6 in capturing seasonal and subseasonal variability of Indian summer monsoon

被引:6
作者
Agrawal, Nishtha [1 ]
Singh, Bhupendra Bahadur [2 ]
Pandey, Vivek Kumar [1 ]
机构
[1] Univ Allahabad, K Banerjee Ctr Atmospher & Ocean Studies KBCAOS, Nehru Sci Ctr, Inst Interdisciplinary Studies, Prayagraj 211002, India
[2] Minist Earth Sci, Indian Inst Trop Meteorol, Pune 411008, Maharashtra, India
关键词
Indian summer monsoon; RegCM; Active and break spells; CUMULUS PARAMETERIZATION SCHEMES; INTRASEASONAL OSCILLATIONS; INTERANNUAL VARIABILITY; SIMULATION; PRECIPITATION; CIRCULATION; IMPACTS;
D O I
10.1016/j.dynatmoce.2021.101203
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Climate modeling studies in the context of Indian summer monsoon (ISM) variability have usually been performed on the seasonal and interannual timescales. The present study assesses the fidelity of the Regional Climate Model (RegCM v4.6) in capturing the subseasonal active and break spells along with the seasonal mean rainfall during the ISM season. The model fields are obtained from 24 years (1982-2005) of simulation and validated against the observations and latest reanalyzed ERAS data products. Our analysis indicates that RegCM v4.6 fairly captures the large scale features of ISM and improvement in seasonal rainfall is noted as compared to its precedent RegCM v4.4. At subseasonal timescales, though the model captures the active and break spells of ISM, the length and frequency of these events seem inconsistent as compared to the observations. Occurrences of breaks and associated circulation features are mostly consistent but the active spells are significantly misconstrued in the model. The dry air intrusion from the western region and lack of monsoon low over the mainland and Bay of Bengal seem to suppress the precipitation in the model. This subseasonal bias might persist due to systematic errors linked to the lack of ocean coupling, inefficiency of land surface and cumulus parameterization schemes in the model. Overall, RegCM v4.6 offers improvements at seasonal timescale but needs further improvements to realistically represent the subseasonal variability of ISM.
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页数:15
相关论文
共 62 条
[1]   Simulation of monsoon intraseasonal oscillations in a coarse-resolution aquaplanet GCM [J].
Ajayamohan, R. S. ;
Khouider, Boualem ;
Majda, Andrew J. .
GEOPHYSICAL RESEARCH LETTERS, 2014, 41 (15) :5662-5669
[2]  
Asoka A, 2017, NAT GEOSCI, V10, P109, DOI [10.1038/NGEO2869, 10.1038/ngeo2869]
[3]  
Bhaskaran B, 1998, MON WEATHER REV, V126, P3124, DOI 10.1175/1520-0493(1998)126<3124:IOITIS>2.0.CO
[4]  
2
[5]   Performance of regional climate model in simulating Indian summer monsoon over Indian homogeneous region [J].
Bhatla, R. ;
Verma, Shruti ;
Ghosh, Soumik ;
Mall, R. K. .
THEORETICAL AND APPLIED CLIMATOLOGY, 2020, 139 (3-4) :1121-1135
[6]   Dominant control of the South Asian monsoon by orographic insulation versus plateau heating [J].
Boos, William R. ;
Kuang, Zhiming .
NATURE, 2010, 463 (7278) :218-U102
[7]   Ocean Surface Impacts on the Seasonal-Mean Precipitation over the Tropical Indian Ocean [J].
Chen, Mingyue ;
Wang, Wanqiu ;
Kumar, Arun ;
Wang, Hui ;
Jha, Bhaskar .
JOURNAL OF CLIMATE, 2012, 25 (10) :3566-3582
[8]   Dynamical Response of the South Asian Monsoon Trough to Latent Heating from Stratiform and Convective Precipitation [J].
Choudhury, Ayantika Dey ;
Krishnan, R. .
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2011, 68 (06) :1347-1363
[9]   Comprehensive test of different cumulus parameterization schemes for the simulation of the Indian summer monsoon [J].
Das, S ;
Mitra, AK ;
Iyengar, GR ;
Mohandas, S .
METEOROLOGY AND ATMOSPHERIC PHYSICS, 2001, 78 (3-4) :227-244
[10]   Simulation of Indian summer monsoon circulation and rainfall using RegCM3 [J].
Dash, S. K. ;
Shekhar, M. S. ;
Singh, G. P. .
THEORETICAL AND APPLIED CLIMATOLOGY, 2006, 86 (1-4) :161-172