Alaskan Winter Storm with Ice
This example tests ADCIRC version 55 (and beyond). It tests the simulation of the storm tides in a regional Alaska domain under astronomical and atmospheric forcing in November 2011 during a strong winter storm in the presence of sea ice (affecting the surface wind drag). The results of interest are the global elevations, velocities and meteorology. The test finishes in about 5 minutes in serial ADCIRC for two weeks of simulation. Find the test at the GitHub test suite.
The mesh was generated using the OceanMesh2D Alaska Example_8_AK.m. The domain encompasses the Gulf of Alaska, Bering Sea, and Chukchi Sea with a minimum resolution of 5 km, comprised of 15,876 vertices and 27,757 triangular elements.
ICS= 20: Equal-Area cylindrical projection.
IM= 513111: Uses the implicit scheme for the linear component of the gravity wave term (computational time step is 4 minutes).
NTIP= 2: Equilibrium tide + self-attraction and loading tide (read from a fort.24 file) forcing for 8 tidal constituents.
NWS= 14014: Reads from GRIB2 files that specify the global atmospheric forcing and sea-ice concentration (6-hourly CFSv2 reanalysis data). Sea-ice concentration affects the wind drag coefficient.
WTIMINC= 21600, 21600: First value gives the temporal interval of the GRIB2 met data (6 hours), second value gives the temporal interval of the GRIB2 ice data (6 hours) - these should always be the same.
A00, B00, C00= 0.4, 0.4, 0.2: Ensures that the implicit scheme is stable with a fairly large time step.
ESLM= -0.2: Enables the Smagorinsky turbulence closure with a coefficient of 0.2.
NOUTGE= 5: Outputs the global elevations into a netCDF4 fort.63 file.
NOUTGV= 5: Outputs the global velocities into a netCDF4 fort.64 file.
NOUTGM= 5: Outputs the global meteorology into a netCDF4 fort.73 file (pressure) and a netCDF4 fort.74 file (velocity).
- internal_tide_friction: Spatially varying linear wave drag fort.13 file attribute accounting for energy conversion due to internal tide generation in the deep ocean.
- &WarnElevControl namelist: Set "WarnElev", the warning elevation level, to 30-m (elevations reach beyond 20-m [default] but remain below 30-m).
- &metControl namelist: Set "rhoAir", to 1.29193 (density of air at 0 deg C for 1013 mbar); set "WindDragLimit" equal to 0.0025; set "invertedBarometerOnElevationBoundary" to true (in Alaska extremely large-scale low pressure systems persist and cross over the open boundaries, so it is important to have the inverted barometer condition along the elevation specified boundary); set "outputWindDrag" to true.
- Joyce, B.R., Pringle, W.J., Wirasaet, D., Westerink, J.J., Van der Westhuysen, A.J., Grumbine, R., Feyen, J., 2019. High resolution modeling of western Alaskan tides and storm surge under varying sea ice conditions. Ocean Model. 141, 101421. doi:10.1016/j.ocemod.2019.101421