Implementation of GIS Tools in Oceanographic Support of Navy Operations

With the increasing volume of geophysical data available from different sensors, and the subsequent requirement to quantify uncertainty in both interpreting the data and forecasting/nowcasting the marine environment for Navy operations, it is imperative to utilise tools capable of merging these data into a comprehensive picture. These data can be appropriately handled in a geographic information system (GIS) where data are fused so as to provide useful information and analyses. Oceanographic measurements like surface elevation, profiles of temperature and salinity, and currents can all be incorporated into a set of layers correlated to geographic information like bathymetry and topography. In addition, operational forecasters can incorporate oceanographic parameter fields from numerical prediction models to create a comprehensive picture of the battlespace environment. These measurements are also used for validation of forecast models. ArcMAP, developed by Environmental Systems Research Institute, is a GIS application used by the Naval Research Laboratory (NRL) and naval operational meteorological and oceanographic centers to analyse the environment in support of a range of Navy missions. For example, acoustic propagation in the ocean is described with a three-dimensional analysis of sound speed that depends on profiles of temperature, pressure and salinity predicted by the Navy Coastal Ocean Model. Another example is the evaluation of tide-induced currents in littoral regions predicted by high-resolution models like the Gerris Flow Solver, a computational fluid dynamics model that is applied to oceanographic problems using adaptive mesh refinement. A third application of ArcMAP is the comparison of predictions from the Los Alamos Sea Ice Model (CICE) to observed ocean currents and winds. The data and model output for these examples must include georeferencing information suitable for accurately placing the data within the ArcMAP framework. NRL has developed tools that facilitate merging these geophysical data and their analyses, including intercomparisons between model predictions as well as comparison to validation data. The verification and validation procedure may include enhancements curve, time series, and statistics. This methodology produces new insights and facilitates identification of potential problems in ocean prediction.