PCTides Validation Test Report

Abstract

Abstract : The Naval Research Laboratory (NRL) has built a globally relocatable tide-surge forecast system. Currently, this system runs on a UNIX platform, but was originally designed for PC-based use, and, as such, is referred to as PCTides. The system is composed of a two-dimensional barotropic ocean model, which is driven by tidal forcing and/or surface wind and pressure forcing. PCTides is applied to the user's area of interest to provide a hindcast or forecast of tidal amplitude, phase and two-dimensional barotropic ocean currents. The PCTides system uses the solutions from a global tide model Finite Element Solutions 99 (FES99) to provide global boundary conditions. The system also contains a 2-min global bathymetry database (the NRL DBDB2 database) to define the model's geometry and bathymetry. Wind forcing for PCTides comes from a number of sources. If the user has access, the Navy's Global Atmospheric Prediction System (NOGAPS), or the Coupled Ocean & Atmospheric Mesocale Prediction system (COAMPS) may be used. Based on this model, hurricane forcing can be generated that can provide surface pressure and winds to drive the two-dimensional barotropic ocean model and generate a storm surge. One major advantage of PCTides is that the model has the ability to be rapidly relocated to areas of interest. The tidal heights can be generated at a user-specified latitude/longitude position and, therefore, is not dependent on a tidal look up table or preexisting database of preselected locations.