Singh Vivek, Srivastava Atul Kumar, Gupta Anu, Konduru Rakesh Teja, Singh Amarendra, Singh Sumit, Kumar Arun, Bisht Deewan Singh, Singh Abhay Kumar
Indian Institute of Tropical Meteorology, (New Delhi Branch), R-Block, New Rajendra Nagar, Ministry of Earth Sciences (MoES), Government of India, 110060, India; Department of Physics, Banaras Hindu University (BHU), Varanasi, Uttar Pradesh 221005, India.
Indian Institute of Tropical Meteorology, (New Delhi Branch), R-Block, New Rajendra Nagar, Ministry of Earth Sciences (MoES), Government of India, 110060, India.
Sci Total Environ. 2024 Nov 15;951:175501. doi: 10.1016/j.scitotenv.2024.175501. Epub 2024 Aug 13.
The present research investigates the dynamics and underlying causes contributing to the exceptional intensity of Super Cyclonic Storm (SuCS) Amphan (16th to 21st May 2020) over the Bay of Bengal (BoB), as well as its impact on aerosol redistribution along the four cities of eastern coast and north-eastern India. Notably, the SuCS was formed during the first phase of the COVID-19 lockdown in India, giving it a unique aspect of study and analysis. Our analysis based on 30 years of climatology data from Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) reanalysis reveals 'positive' monthly anomalous winds (0.8 to 1.6 m/s) prevailed over the central BoB for May 2020. The present study further found the evolution of 'barrier layer thickness'(BLT) leading up to landfall, noting a thickening trend from 8 to 3 days before landfall, contributing to maintaining warmer sea surface temperatures near the coast. Additionally, utilizing European Centre for Medium-Range Weather Forecasts (ECMWF), reanalysis version-5 (ERA-5) data, a mean positive sea surface temperature (SST) anomaly of 0.8 to 1 °C was observed 'before' cyclone period (10-15 May 2020) near the cyclogenesis point. A detailed examination of Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) vertical cross-section plots during the cyclone's intensification stage reveals the presence of high-altitude clouds composed primarily of ice crystals. Further, analysis also indicates that the cyclone transported Sea-salt PM aerosols from the ocean, dispersing them in the landfall region.The aerosol optical Depth (AOD) data obtained from the National Aeronautics and Space Administration's (NASA) 'Clouds and the Earth's Radiant Energy System (CERES)' mission and MERRA-2 were also analysed, revealing that the cyclone redistributed aerosols over the Bengal basin region (mainly over 'Kolkata') and three other nearby cities along the track of the cyclone (i.e., Bhubaneswar (Odisha) Agartala (Tripura) and Shillong (Meghalaya) respectively).
本研究调查了导致超级气旋风暴“安攀”（2020年5月16日至21日）在孟加拉湾异常强烈的动态过程和潜在原因，以及它对印度东海岸和东北部四个城市气溶胶再分布的影响。值得注意的是，这场超级气旋风暴是在印度新冠疫情封锁的第一阶段形成的，这使其具有独特的研究和分析价值。我们基于现代时代回顾性分析研究与应用版本2（MERRA - 2）再分析的30年气候学数据进行分析，结果显示2020年5月孟加拉湾中部盛行“正”月异常风（0.8至1.6米/秒）。本研究还发现了风暴登陆前“障碍层厚度”（BLT）的演变情况，注意到在登陆前8至3天有增厚趋势，这有助于维持海岸附近较温暖的海面温度。此外，利用欧洲中期天气预报中心（ECMWF）再分析版本5（ERA - 5）数据，在气旋生成点附近的气旋期之前（2020年5月10日至15日）观测到平均正海表面温度（SST）异常为0.8至1摄氏度。对气旋增强阶段的云 - 气溶胶激光雷达和红外探路者卫星观测（CALIPSO）垂直剖面图进行详细检查发现，存在主要由冰晶组成的高空云。此外，分析还表明气旋从海洋输送海盐颗粒物气溶胶，并将其散布在登陆区域。还对从美国国家航空航天局（NASA）的“云和地球辐射能量系统（CERES）”任务以及MERRA - 2获得的气溶胶光学厚度（AOD）数据进行了分析，结果显示气旋在孟加拉盆地地区（主要在“加尔各答”）以及气旋路径沿线的其他三个附近城市（即分别为布巴内斯瓦尔（奥里萨邦）、阿加尔塔拉（特里普拉邦）和西隆（梅加拉亚邦））重新分布了气溶胶。
