Improving the model simulation of surface wave impacts on air-sea fluxes, turbulent boundary layers, and their impacts on Indian monsoons in the Arabian Sea
Abstract
Approved for public release: ASTraL will improve in situ characterization of air-sea exchanges of heat, mass, and momentum, including amplitudes and space-time variability, and provide useful and practical observational constraints for prediction models across scales. Since air-sea fluxes and their interactions with turbulent boundary layers in the ocean and atmosphere are entirely parameterized in prediction models, accurate representation of these coupled interactions is critical for improved predictive capabilities in Earth System modeling. We propose a model-data synthesis project that will validate, refine, and re-engineer (if necessary) the parameterizations for air-sea fluxes mediated by surface waves and their interaction with turbulent boundary layer processes in the Arabian Sea. The focus is on the spring to summer transition season, where the Arabian Sea exhibits peculiar sea states dominated by swell and mixed seas, whose effects on air-sea fluxes remain poorly captured even in the most advanced bulk flux algorithms. Subsequentimpacts on the formation and collapse of the mini warm pool and the onset of the summer monsoons in simulation and forecast models must be quantified.A crucial element of the project is to use the high-resolution, fully coupled ocean-atmosphere-wave model simulations to validate and refine critical aspects of the #wave-based# air-sea flux parameterizations in the latest and next-generation COARE algorithm against the existing and future in situ measurements in the region. This will, in turn, constrain the existing wave-mediated (or wave-aware) parameterizations for turbulent exchanges and dissipation in the oceanic and atmospheric boundary layers overmultiple winds and wave conditions. The improved bulk formula and turbulent boundary layer coupling procedures will be implemented and tested in Weather and Research Forecast (WRF) and Coupled Forecast System version 2 (CFSv2), the models that are currently operational in various institutions across India and the US, to characterize the upper ocean and lower atmospheric structure over the mini warm pool and determine the simulation and prediction sensitivity of monsoon onset vortex and monsoon precipitation.The project will also inform the ASTraL field experiments on what enhancements might be needed in the sampling plans to resolve wind, wave, and upper-ocean conditions critical for the improved characterization and parameterization of the coupled boundary layer processes. By theend of this project, we will have advanced the process-level understanding of coupled ocean-atmosphere-wave interactions during thepre-monsoon and the onset of the summer monsoon seasons and have more accurately represented their effects in the simulation and operational models. The project will hinge on close collaborations with the DRI teams of in situ measurements (e.g., wave, wind, and near-surface turbulence), process-oriented modeling (e.g., LES, regional models), and our modeling partners in India (e.g., IIT-M Pune, INCOIS) to guide the field observations, advance the parameterizations, and quantify the impacts in operational systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 12, 2023
- Source ID
- N000142312250
Entities
People
- Hyodae Seo
Organizations
- Office of Naval Research
- United States Navy
- Woods Hole Oceanographic Institution