Implementation of Wetting and Drying in NCOM: Description and Validation Test Report

This report discusses the implementation and testing of wetting and drying (WAD) in the Navy Coastal Ocean Model (NCOM). Note that NCOM is run as a stand-alone ocean model and also as part of the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS), which provides for one- or two-way coupling among atmosphere, ocean, and wave models. The WAD in NCOM is tested by running simulations of (a) idealized experiments that have analytical solutions that can be compared against, (b) laboratory experiments that have observed results that can be compared against, (c) several coastal regions that have notable WAD areas, i.e., San Francisco Bay, Chesapeake Bay, and Cook Inlet in Alaska, and (d) Hurricane Ike, which caused extensive flooding along the Texas and Louisiana coasts in 2008. The pros and cons of the WAD scheme implemented in NCOM are discussed. This WAD scheme has the main advantages that it does not require any special modification of the bathymetry and is fairly robust. The main disadvantages of the WAD scheme are that additional calculations are required and the timestep may need to be decreased, both of which will increase the NCOM run time. The original document contains color images.