Validation and sensitivity study of a Sigma-coordinate ocean model using the Skagex dataset

Abstract

Numerical ocean models are now being applied in numerous oceanographic studies. However, standards and procedures for evaluation of these models are far from established. In this paper the use of data from hydrographical transects taken repeatedly over a period for model validation is suggested. In order to illustrate the evaluation technique a 3-dimensional sigma-coordinate model system is set set up for an extended North Sea and run in the period from October 1989 to August 1990. The model system consists of a "large scale" model with 20km horizontal resolution producing the open boundary conditions to a "fine scale" model with 4km horizontal resolution set up for the Skagerrak/Kattegat area. During SKAGEX-90 hydrographical stations were taken every third day along several fixed transects. From these datasets mean values and standard deviations, with respect to time, of salinity and temperature are produced and compared to corresponding measures from model results.