A simulation of the Southern North Sea in comparison with measurements from the North Sea Project. Part 1: Temperature

The accurate simulation of the annual cycle and vertical structure of tempe rature is crucial to biological and water quality modelling in shelf-seas. As a precursor to these applications, we present a three-dimensional barocl inic simulation of the southern North Sea at the time of the North Sea Proj ect (NSP), with density controlled by a prognostically evolving temperature field forced by surface heat fluxes from bulk formulae. The model results are compared, on a point for point basis, with CTD data from the NSP. The a nnual cycles in mean temperature, mean surface to bed temperature differenc e and mean thermocline depth, and the extent of the summer stratification a re found to be in good agreement. Overall, the correlation between modelled and observed temperature is r(2) = 0.95 for the depth mean component and r (2) = 0.64 for the depth varying component. The rms deviation is about 1 de gree. We assess the sources of these errors and the performance of the Mell or-Yamada level 2.5 turbulence closure as implemented in this model. (C) 19 99 Elsevier Science Ltd. All rights reserved.