Comparative Analysis of Different Meteorological Parameters on Storm Surge Simulation during Tropical Cyclone (TC) Tauktae

Rajendiran, S.; Beulah, H.-R., and Balaji, R., 2024. Comparative analysis of different meteorological parameters on storm surge simulation during Tropical Cyclone (TC) Tauktae. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 1016–1020. Charlotte (North Carolina), ISSN 0749-0208. Tropical Cyclone (TC) Tauktae originated from a low-pressure system in the Arabian Sea on May 14, 2021. Rapidly intensifying into an Extremely Severe Cyclonic Storm (ESCS) under favorable conditions, it emerged as a formidable cyclone. On May 17, 2021, TC Tauktae made landfall on the Gujarat coast, marking one of the most powerful storms since the Gujarat cyclone of 1998. The matured system approached the low lying areas of Gujarat coastline, where Diu and coastal districts of Saurashtra reportedly recorded a surge of 3 to 4 meters above astronomical tide. The precise estimation of storm surge relies heavily on the accuracy of meteorological inputs provided to the surge model. This is crucial for determining how the storm dynamics are represented, particularly as the matured system approaches the land. In this research, the study involves a comparison of simulated storm water levels using the Delft3D-FM storm surge model. The model is driven by wind and pressure fields obtained from multiple sources, including the India Meteorological Department (IMD) best track data and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data. IMD track information is used as inputs into Delft3D-FM model which is time and space varying along the storm track. The simulation results for water levels using IMD wind data were compared to ECMWF reanalysis winds. The accuracy of these simulated water levels was validated against tide gauge observations along the West coast of India. Near JNPT-Mumbai, the simulated storm surge was 0.79 meters for IMD data and 0.49 meters for the ERA5 data, while the observed storm surge was 0.78. The strong correlation between observed and simulated storm surge indicates that IMD data enhances storm surge prediction accuracy. Due to computational limitations, the study does not incorporate wave-induced effects.