Too strong currents in hurricane-induced flow

[hpd14thu]

I use the hurricane to force the upper ocean, and the wind speed is up to 55m/s. And there is a problem, the upper ocean's currents is too strong compared to the data. I wonder that if I have choose some cppoptions when I try the high-speed wind cases?

[chegermiller]

Hi hpd14thu,

Thanks for your questions.

1) Are the wind speeds also overestimated compared to the data?

2) There has been an observed rolloff of drag at high wind speeds that is not coded into the current version of bulk fluxes. This will be included in the next COAWST version, but you can send me an email at chegermiller@whoi.edu or search for DRAGLIM_DAVIS in COAWST/WRF/phys/module_sf_mynn.F or COAWST/WRF/phys/module_sf_myjsfc.F for the one line limiter that you can modify to add to your bulk_flux.F in ROMS/Nonlinear.

For hurricane applications, there are many papers that show that coupling ocean-atm-wave models improves predictions of ocean variables. Keep us updated.

Christie

[hpd14thu]

Hi hpd14thu,

Thanks for your questions.

1) Are the wind speeds also overestimated compared to the data?

2) There has been an observed rolloff of drag at high wind speeds that is not coded into the current version of bulk fluxes. This will be included in the next COAWST version, but you can send me an email at chegermiller@whoi.edu or search for DRAGLIM_DAVIS in COAWST/WRF/phys/module_sf_mynn.F or COAWST/WRF/phys/module_sf_myjsfc.F for the one line limiter that you can modify to add to your bulk_flux.F in ROMS/Nonlinear.

For hurricane applications, there are many papers that show that coupling ocean-atm-wave models improves predictions of ocean variables. Keep us updated.

Christie

Hi Christie, thank you for your reply. After testing by myself, I make sure that the limited Cd at high wind speeds is the issue point. Thank you and I have sent you an email.

Peida