Dear ROMS users,
I want to user ROSM simulate the sediment transportation from coast to deep ocean. My domain is the whole East China Sea(117E-133E， 24N-41N)， and the resolution is 10/60 degree. I know the importance of wave in suspending sediments at coastal area, so I need couple the SWAN model to simulate sediment transport. However, the User mannul of SWAN says that this wave mode is not recommended for ocean scale simulation.
I only expect the SWAN model could suspend coastal(depth <30m) sediments in this area when strong wind coming. I don't care about the wave character results. And the User Mannul also says that SWAN can be used on any scale relevant for wind-generated surface gravity waves. So can SWAN model suspend the coastal sediment correctly and not have bad effect to the current field on the ocean scale?
Thanks!
Can SWAN model used to simulate sediment transport on ocean
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nganju
- Posts: 82
- Joined: Mon Aug 16, 2004 8:47 pm
- Location: U.S. Geological Survey, Woods Hole
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Re: Can SWAN model used to simulate sediment transport on oc
One option is to use the SSW_BBL option in ROMS, and directly specify wave height and period throughout the domain, thereby avoiding SWAN. You can use simple wave formulas, for a given wind speed, fetch, and water depth to calculate the wave characteristics, and put those in a netcdf forcing file. SSW_BBL will read the heights and periods, and calculate the near-bed orbital velocity (Dean and Dalrymple), and the wave-current shear stresses (if either Madsen or Styles/Glenn wave-current interaction is also specified). These shear stresses will then be used to calculate sediment transport.
I used this method with idealized winds and it worked well for resuspending sediment during large events. If using in shallow water with large tidal range (for example, 2 m depths with 1 m tidal range), it will be important to make sure SSW_BBL uses total water depth (h+zeta) to calculate orbital velocity. I think the current version only uses "h" for the Dean and Dalyrmple formula. Below are the two studies where I used this method, if you need more information let me know. Good luck...
Ganju, N.K., Schoellhamer, D.H., and Jaffe, B.E., 2009, Hindcasting of decadal-timescale estuarine bathymetric change with a tidal-timescale model. Journal of Geophysical Research-Earth Surface, 114, F04019, doi:10.1029/2008JF001191.
Ganju, N.K., and Schoellhamer, D.H., 2009, Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for robust simulation of geomorphic evolution. Continental Shelf Research, 29, 148-158.
-Neil
I used this method with idealized winds and it worked well for resuspending sediment during large events. If using in shallow water with large tidal range (for example, 2 m depths with 1 m tidal range), it will be important to make sure SSW_BBL uses total water depth (h+zeta) to calculate orbital velocity. I think the current version only uses "h" for the Dean and Dalyrmple formula. Below are the two studies where I used this method, if you need more information let me know. Good luck...
Ganju, N.K., Schoellhamer, D.H., and Jaffe, B.E., 2009, Hindcasting of decadal-timescale estuarine bathymetric change with a tidal-timescale model. Journal of Geophysical Research-Earth Surface, 114, F04019, doi:10.1029/2008JF001191.
Ganju, N.K., and Schoellhamer, D.H., 2009, Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for robust simulation of geomorphic evolution. Continental Shelf Research, 29, 148-158.
-Neil