Circulation characteristics of a monsoon depression during BOBMEX-99 using high-resolution analysis

Journal of Earth system science

M Mandal1¹  S R Kalsi3³  Someshwar Das2²  U C Mohanty1¹  Ananda K Das1¹ 

[1] Center for Atmospheric Sciences, Indian Institute of Technology, Hauz Khas, New Delhi 110 016, India$$;National Center for Medium Range Weather Forecasting, Mausam Bhavan, Lodhi Road, New Delhi 110 003.$$;India Meteorological Department, Mausam Bhavan, Lodhi Road, New Delhi 110 003.$$

关键词: BOBMEX;    high-resolution analysis;    monsoon depression;    MM5.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The skill and efficiency of a numerical model mostly varies with the quality of initial values, accuracy on parameterization of physical processes and horizontal and vertical resolution of the model. Commonly used low-resolution reanalyses are hardly able to capture the prominent features associated with organized convective processes in a monsoon depression. The objective is to prepare improved high-resolution analysis by the use of MM5 modelling system developed by the Pennsyl- vania State University/National Center for Atmospheric Research (PSU/NCAR). It requires the objective comparison of high and low-resolution analysis datasets in assessing the specific convective features of a monsoon depression. For this purpose, reanalysis datasets of NCAR/NCEP (National Center for Atmospheric Research/National Centers for Environmental Prediction) at a horizontal resolution of 2.5° (latitude/longitude) have been used as first guess in the objective analysis scheme. The additional asynoptic datasets obtained during BOBMEX-99 are utilized within the assimilation process. Cloud Motion Wind (CMW) data of METEOSAT satellite and SSM/I surface wind data are included for the improvement of derived analysis. The multiquadric (MQD) interpolation technique is selected and applied for meteorological objective analysis at a horizontal resolution of 30 km. After a successful inclusion of additional data, the resulting reanalysis is able to produce the structure of convective organization as well as prominent synoptic features associated with monsoon depression. Comparison and error verifications have been done with the help of available upper-air station data. The objective verification reveals the efficiency of the analysis scheme.

【 授权许可】

Unknown