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Understanding Wind-Wave-Current Coupling on Hurricane Intensity and Coastal Impacts

Presentation Date
Monday, January 29, 2024 at 2:00pm - Monday, January 29, 2024 at 2:15pm
Location
The Baltimore Convention Center - 343
Authors

Author

Abstract

Extreme wind, rain and storm surge from landfalling hurricanes pose the most threat to the coastal community. Accurate prediction of coastal impacts of hurricanes remains one of the grand challenges in hurricane modeling today. One of the key processes controlling the surface wind, waves, and storm surge is the complex momentum exchange at the air-sea interface. This study focuses on better understanding and modeling of the wind-wave-current coupling and its impact on hurricane intensity and coastal impacts. We use a high-resolution, coupled atmosphere-wave-ocean model, namely the Unified Wave INterface - Coupled Model (UWIN-CM) to investigate the effects of explicit treatment of the atmospheric and ocean stresses on storm structure and intensity over the open ocean and coastal region. Currently, many coupled models are used to determine the impacts associated with TCs. However, to date, these models are inefficient at momentum exchange processes. The ineffectiveness of these models is manifested in the overcooling of the Sea Surface Temperatures (SSTs), leading to the underprediction of TC intensity. Additionally, these models underpredict wave dissipation in coastal areas. In this work, we use UWIN-CM to simulate TC Irene 2011 and Earl 2010. Two simulations were performed for each TC, one in which the stresses were treated conservatively based on wave energy balance (Atmosphere Wave Ocean [AWO]) while in the other the ocean was forced with atmospheric ocean surface stress (Atmosphere Wave Ocean-WindSea [AWO-WS]). The results show that TC structure and intensity are sensitive to variations of the wind and current stress formulations in the fully coupled model. The model simulations are compared with the NHC best track data as well as other available buoy and satellite observations. Over the coastal regions, wave dissipation is strongly enhanced by wave breaking due to wave shoaling, which cannot be captured by simple wind-dependent stress physics. The results from the study indicate that stresses should be treated conservatively to fully capture the effects of momentum exchange processes.

Category
22nd Symposium on the Coastal Environment
Funding Program Area(s)