Oceanographic Expert System Validation Using GOAP Mesoscale Products and Gulf/DART Validation Test Data

Abstract : A prototype oceanographic expert system is being developed by the Remote Sensing Branch of the Naval Oceanographic and Atmospheric Research Laboratory (NOARL). System performance for eddy motion was tested using GEOSAT Ocean Applications Program (GOAP) mesoscale products. A second data set was used to validate the Harvard Gulfcast and the NOARL DART (Data Assimilation Research and Transition program) models. Several types of performance measures were calculate for both warm- and cold-core Gulf Stream eddies. Statistics compiled from the analysis results are presented in both tabular and graphical form. The analysis shows that the expert system performs reasonably well with respect to both eddy motion and eddy size. The expert system's projections are superior to an assumption of no motion out to 14 days. Results with the second (better) data set indicate performance superior to no motion in about two-thirds of the cases. The GOAP results, which used longer than 2 weeks. The expert system tracks ring sizes to within 10% for periods up to 7-11 weeks. Discussion of the results identifies factors that interfere with the validation and strongly indicates factors that interfere with the validation and strongly indicates the need for more data to continue and refine the analysis. A first-order correction to the rule base is proposed, based on the results of this study. That correction should significantly improve the expert system's average eddy motion performance. Changes based upon a more detailed evaluation may also be feasible and could lead to greater improvements.