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Tropical cyclones are the most devastating phenomena among all natural disasters, having taken more than half a million lives all over the world in the last five decades. Cyclones are accompanied by very strong winds, torrential rains and storm surges. The havoc caused by cyclones to shipping in the high seas and coastal habitats along the Indian c...
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... landfall point forecast error has reduced significantly in recent years. The 12 and 24 hr landfall point forecast errors have decreased at the rate of about 16 and 34 km per year respectively during 2003-2012 (Fig. 3). However, the rate of decrease is relatively less in case of landfall time forecast error. ...
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Over the North Indian Ocean (NIO), the months of October-December are known to produce tropical cyclones (TCs) of severe intensity in the Bay of Bengal, which after crossing the coast cause damages to life and property over many countries surrounding the Bay of Bengal. The strong winds, heavy rains and large storm surges associated with TCs are the...
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... About 11 cyclonic disturbances (CDs) with maximum sustained wind speed (MSW) of 17 knots (kt) or more including depression(D)/deep depression (DD) with MSW of 17-33 kt and tropical cyclones (TCs) with MSW of 34 kt or more develop over the North Indian Ocean (NIO) during a year based on data of 1961-2010 (Mohapatra et al., 2014). It includes 9 and 2 CDs over the Bay of Bengal (BOB) and Arabian Sea (AS) respectively. ...
... Out of these, about five intensify into TC including about 4 over BOB and 1 over the AS. About 3 severe TCs (MSW of 48 kt or more) are formed over the NIO during a year (Mohapatra and Sharma, 2019;Mohapatra et al., 2014). The frequency of TCs is maximum during postmonsoon season (October-December) followed by premonsoon (March-May) and monsoon (June-September) season [India Meteorological Department (IMD), 2008]. ...
... IMD has taken a number of steps in recent years to continuously enhance the TC database to enable the research and development for the improvement in monitoring, numerical modelling and forecasting. Specially, in the satellite era since 1961, there has been significant improvement in TC monitoring which has further advanced with augmentation of upper air observations with pilot balloons in 1960s, radiosonde and radio wind (RS/RW) observations in 1970s, cyclone detection radars in 1970s, introduction of Indian satellites in 1980s, meteorological buoys in late 1990s and augmentation of surface observational network including automatic weather stations and automatic rain gauges in 2000s (Mohapatra et al., 2012b and2014). Though, the TC data base is maintained by IMD since 1877, it is reasonably accurate for any kind of research and development in terms of climatological analysis, hazard analysis, landfall characteristics and impact studies for the period 1961 onwards (Mohapatra et al., 2012b). ...
India Meteorological Department (IMD) categorises the tropical cyclones (TCs) as cyclonic storm (CS), severe cyclonic storm (SCS), very severe cyclonic storm (VSCS), extremely severe cyclonic storm (ESCS) and super cyclonic storm (SuCS). The long term climatology of TCs in these categories and the trends in frequency and intensity of TCs in these categories developing over the NIO and crossing different coastal regions are limited. Hence a study has been undertaken to analyse the characteristics of genesis and intensification of CDs in the above categories developing over the NIO and crossing different coastal regions based on the data of satellite era (1965-2020). The most intense TCs (ESCS & above) cross the coast maximum over Odisha (ODS) followed by Andhra Pradesh (AP)/Myanmar (MMR) & Bangladesh (BDS) and low intensity TCs (CS/SCS) cross maximum over BDS followed by AP, ODS & Tamilnadu (TN) and medium intensity TCs (VSCS) cross maximum over TN/AP/BDS followed by ODS/West Bengal (WB)/MMR during a year as a whole. While maximum CS/SCS cross BDS, maximum VSCS cross BDS/MMR and maximum ESCS cross MMR coast during pre-monsoon season. While maximum CS/SCS/VSCS cross AP coast, maximum ESCS cross ODS coast during post monsoon season. Over the AS, the landfall frequency of VSCS is maximum over Arabia - Africa (AA) coast followed by Saurashtra and Kutch coast. The coastal vulnerability due to ESCS continues over the Bay of Bengal (BoB) region, as there is no significant trend in the frequency of genesis of ESCS and above intensity storms, though there is decreasing trend in the genesis frequency of D/DD, CS, SCS, VSCS over the BoB. It has increased over the AA coast due to increasing trend in frequency of genesis of VSCS and above intensity storms over Arabian Sea.
This study aims to Bnd out the variations of central pressure (intensity) of intense tropical cyclones (TCs) with sea surface temperature (SST), mid-tropospheric relative humidity (MRH), mid-tropospheric instability (MI), vertical wind shear (VWS), 200 hPa divergence, and surface latent heat Cux (SLHF) during the lifetime of intense TCs, and determine the most crucial parameter which shows the highest correlation with central pressure (intensity). Out of all these parameters, SLHF is highly correlated (R 2 = 0.74) with the central pressure of intense TCs. Increase and decrease of SLHF correspond to decrease and increase of TCs central pressure (increase and decrease in TCs intensity). The highest SLHF corresponds to the lowest central pressure (highest intensity).
