Obstruction Grids Impact on Wave Propagation and WW3 Run Time for Two Regions: Indonesia and the Caribbean.

We evaluate the use of obstruction grids for two different Coupled Ocean/Atmosphere Mesoscale Prediction System On Scene (COAMPS-OS) regions running the Wavewatch III spectral model at FNMOC to account for wave attenuation by unresolved islands. We selected two operational areas that have a number of small islands and atolls, namely the area around the Pacific Indonesian through-flow and the Caribbean region in the Atlantic. These are also well developed areas that have a number of wave buoys for verification of wave height at absolute points. Wave height measurements from satellite altimeters will also be used to verify the model forecasts.

We will also be monitoring run time of the project and comparing to the current operational areas that do not include obstruction grids.

We will be using the National Centers for Environmental Prediction (NCEP) GridGen program for use with WW3.