T M BALAKRISHNAN NAIR
Articles written in Journal of Earth System Science
Volume 128 Issue 8 December 2019 Article ID 0226 Research Article
This study discusses the impact of high-resolution winds on the coastal waves and analyses the effectiveness of the high-resolution winds in recreating the fine-scale features along the coastal regions during the pre-monsoon season (March–May). The influence of the diurnal variation of winds on waves is studied for the Tamil Nadu coastal region using wind fields from weather research and forecast (WRF) (3 km) and European Centre for Medium-Range Weather Forecasts (ECMWF) (27.5 km). The improvement in the coastal forecast is then quantified with wave rider buoy observations. The high-resolution wind fields simulated fine-scale features like land–sea breeze events and showed good agreement with observation results. The error in the wave height and period is reduced by 8% and 46%, respectively, with the use of high-resolution forcing winds WRF over ECMWF, although the overestimation of wave energy on high frequencies due to overestimated WRF winds remains as a challenge in forecasting. The analysis also shows the importance of accurate wave forecast during a short-duration sudden wind ($\sim$12 m/s) occurrence in southern Tamil Nadu near Rameswaram during the pre-monsoon period. Low pressure forms over Tamil Nadu due to the land surface heating, resulting in a sudden increase of winds. High winds and steep waves which cause damage to the property of the coastal community near Rameswaram also were well simulated in the high-resolution forecast system with WRF winds.
Volume 130 All articles Published: 2 June 2021 Article ID 0111 Research Article
The present study describes the active role of met-ocean parameters on the heavy flooding that occurred during July 2018 in the Kuttanad region, Kerala. The model-derived data as well as observations showed a high anomaly of wave height in July 2018 off Kerala was not correlated with local wind anomaly and indicated possible connection of wave anomalies to swell waves. The high period and high amplitude swell waves suggest a wave setup formation near shore for flooding intensification in the Kuttanad region. The wave observation at an open ocean location (AD09) also confirms the presence of high swell waves during the same period. Anomalous elevated non-tidal sea level was evident in the tide gauge data. The narrow opening at Thottappally, is not able to discharge the outflow of the heavy flood water and it is further complicated by the wave setup at the entrance caused by long period swell waves.
Volume 130, 2021
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