Effects of wind-wave misalignment on air-sea momentum flux and drag coefficient

Project Information

oceanography
Project Status: Complete
Project Region: CAREERS
Submitted By: Gaurav Khanna
Project Email: tetsuhara@uri.edu
Project Institution: University of Rhode Island -- Bay Campus
Anchor Institution: CR-University of Rhode Island

Mentors: Tetsu Hara
Students: Joshua Port

Project Description

We conduct Large Eddy Simulation (LES) studies of turbulent wind over surface waves that propagate in different directions from wind direction. The results are used to better understand how misaligned waves modify the wind turbulence and resulting air-sea momentum flux. Recent observational studies show that the drag coefficient (air-sea momentum flux) is significantly reduced when dominant wind-forced surface waves are misaligned from the local wind. Misaligned waves are particularly common under tropical cyclones and/or in shallow water coastal regions. The results from this study will be used to develop a new parameterization of sea-state dependent drag coefficient (air-sea momentum flux) including the effect of misaligned surface waves. Such a parameterization is needed for various coupled atmospheric, wave, and ocean prediction models. In particular, tropical cyclone prediction models are expected to be significantly improved by including the newly developed parameterization.

The student will obtain extensive experience working on an HPC cluster (command-line Linux, Fortran code compilation, SLURM job scheduler, optimal submission parameters etc.) and will also learn to use available visualization tools. The project will require access to a modest HPC system that provides ~1024 cores (128 cores x 8 nodes, 64 cores x 16 nodes, etc.) and a scratch filesystem.

Additional Resources

Launch Presentation:
Wrap Presentation: 6

Project Information

oceanography
Project Status: Complete
Project Region: CAREERS
Submitted By: Gaurav Khanna
Project Email: tetsuhara@uri.edu
Project Institution: University of Rhode Island -- Bay Campus
Anchor Institution: CR-University of Rhode Island

Mentors: Tetsu Hara
Students: Joshua Port

Project Description

We conduct Large Eddy Simulation (LES) studies of turbulent wind over surface waves that propagate in different directions from wind direction. The results are used to better understand how misaligned waves modify the wind turbulence and resulting air-sea momentum flux. Recent observational studies show that the drag coefficient (air-sea momentum flux) is significantly reduced when dominant wind-forced surface waves are misaligned from the local wind. Misaligned waves are particularly common under tropical cyclones and/or in shallow water coastal regions. The results from this study will be used to develop a new parameterization of sea-state dependent drag coefficient (air-sea momentum flux) including the effect of misaligned surface waves. Such a parameterization is needed for various coupled atmospheric, wave, and ocean prediction models. In particular, tropical cyclone prediction models are expected to be significantly improved by including the newly developed parameterization.

The student will obtain extensive experience working on an HPC cluster (command-line Linux, Fortran code compilation, SLURM job scheduler, optimal submission parameters etc.) and will also learn to use available visualization tools. The project will require access to a modest HPC system that provides ~1024 cores (128 cores x 8 nodes, 64 cores x 16 nodes, etc.) and a scratch filesystem.

Additional Resources

Launch Presentation:
Wrap Presentation: 6