Wind and wave climate characteristics and extreme parameters in the Bay of Bengal

Abstract

Numerical hindcast of typhoon events in the Bay of Bengal from 1981 to 2015 is performed using the Jelesnianski typhoon model. Additionally, with the NCEP wind field data (1981–2015) as the background field, the wind fields over the Bay of Bengal in the 35-year period are reconstructed. With the reconstructed wind field as the driving wind field, wave data for the Bay of Bengal for the 35-year period are simulated by the SWAN wave model. The comparisons showed that the simulated results are in good agreement with the measured data. Based on the hindcast data, the average temporal and spatial distribution characteristics of wind and wave in the Bay of Bengal, including annual, seasonal and monthly average characteristics, are analyzed. Wind and wave in the Bay of Bengal are found to exhibit similar temporal and spatial distribution characteristics. Both wind speeds (Ws) and significant wave height (Hs) are higher in the central bay than in the southern bay and the northern coastal regions. In addition, Ws and Hs are the highest in summer, followed by those in spring and autumn; Ws and Hs are the lowest in winter. Based on annual extreme wind and wave data, extreme wind and wave parameters in the Bay of Bengal are calculated. The results show that the maximum Ws and Hs of 50-year return period in the Bay of Bengal exceed 50 m/s and 16 m, respectively.