摘要: The tropical cyclone is a majestic, yet violent atmospheric weather system occurring over tropical waters.Their majesty produces the significant range of spatial scales: from the mesoscale to the larger synoptic-scale.Their asso... 展开 The tropical cyclone is a majestic, yet violent atmospheric weather system occurring over tropical waters.Their majesty produces the significant range of spatial scales: from the mesoscale to the larger synoptic-scale.Their associated violent winds, heavy rainfall and storm surges are often the cause of damage and destruction in their path. In this study two tropical cyclones (TCs) KOMEN in 2015 during the peak-monsoon and ROANU in 2016 during the pre-monsoon seasons are analyzed by using the Advanced research of the Weather Research and Forecasting (WRF-ARW) Model to examine its ability to reproduce the heavy rainfall over western Myanmar due to the interaction between the tropical cyclone and topography.In addition, the Indian Institute of Technology-Delhi (IIT-D) based surge model is used to understand the phenomena of the storm surge and to investigate its ability to generate the surge over western Myanmar. To understand the mechanism of heavy rainfall, an attempt has been made to simulate a heavy rainfall event on 25 July-1 August 2015 over western Myanmar using (WRF-ARW) model version (3.7) with Yonsei University scheme (YSU) for planetary boundary layer and WRF Single-Moment 3-class for microphysics scheme (WSM3) on a single domain at 3 km horizontal resolutions.The initial and boundary conditions to simulate the TC KOMEN are obtained from the National Center for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) global final (FNL) analysis dataset on resolution of 1° × 1° grids and six-hourly intervals has been used to frnd the link between rainfall and prevailing atmospheric dynamics on surface during the heavy rainfall event. The model performance was assessed by examining the different predicted parameters like geopotential height, upper and lower level circulations, convergence, vorticity, temperature, heat flux, moisture, and rainfall.The strength of convective instability is also analyzed with the convective available potential energy (CAPE).The large-scale circulation features, moisture, and temperature are compared with those in the National Centers for Environmental Prediction analyses.The model derived rainfall was validated with Department of Meteorology and Hydrology (DMH) observed rainfall.The results indicate that the WRF model was able to simulate reasonably well the heavy rainfall event.The model suggested that the strong westerly wind flow transported high amount ofmoistnre from the Bay of Bengal towards the west coast of Myanmar and adjoining areas and this high rainfall events over western part of Myanmar might be characterized by the positive vorticity, strong convergence and low level jet which support the moisture flux and instability at low level. To get the accurate forecast of heavy rainfall, TC track forecast is important.Thus, the impact of different microphysics and boundary schemes and terrain settings on the heavy rainfall over western Myanmar associated with TC ROANU (2016) are investigated using the WRF model.The impact of MP and PBL schemes are investigated by using the initial and boundary conditions to simulate the TC ROANU are obtained from the NOAA National Operational Model Archive and Distribution System (NOMADS) global forecast system (GFS) dataset on resolution of 0.5° × 0.5° grids and every six-hourly intervals has been used for the diagnostic analysis. The results show that the mierophysics scheme of Purdue Lin scheme (LIN) produces the strongest cyclone.Six experiments with various combinations of microphysics and boundary schemes indicated that a combination of WRF Single-Moment 6-class (WSM6) scheme and Mellor-Yamada-Janjic (MYJ) best fits to the Joint Typhoon Warning Center (JTWC) data. WSM6-MYJ also performs the best for the track and intensity of rainfall and obtains the best statistics skill scores in the range of maximum rainfall intensity for 48-h.Sensitivity experiments on different terrain settings with normal Rakhine Mountain (NRM), with half of Rakhine Mountain (HRM), and without Rakhine Mountain (WoRM) are designed with the use of WSM6- MYJ scheme.The track of TC ROANU moved northwestward in WoRM and HRM.In these two experiments, the amount of rainfall was larger than NRM.Due to the presence of Rakhine Mountain, TC track moved into Myanmar and the peak rainfall occurred on the leeward side of the Mountain.In the absence of Rakhine Mountain, a shift in peak rainfall was observed in north side of the Mountain.A rich source of moisture most likely originates from divergence of TC wind and horizontal moisture flux (wind) are shown to be the key factor behind the heavy rainfall over western Myanmar. In order to accurately and on time numerical prediction of a surge due to TC, it is a crucial task for disaster mitigation.This study used the (IIT-D)-based surge model to explore the various factors of a surge in Myanmar.Case studies were done wi 收起