Background

Since 1993, most of NWAG’s efforts have focussed on current modelling of the complex and energetic environment of the region. Early model development work was carried out by HydroQual Inc. This provided valuable insight into the modelling of oceanic processes and the model resolution needed to reproduce important features – such as eddies. Building on this work, in 1999, NWAG commissioned the Norwegian Nansen Centre to develop and validate a state-of-the-art 3-D current model for the NWAG region.

Figure 1 shows the overall model system comprising the following multi-level nested models:

Figure1: NWAG nested model system

the outer (approx 20 km) "DIADEM" Atlantic Ocean circulation model

the intermediate (7-8 km) model "NSeaH", covering the N Atlantic and Nordic seas

the fine-grid (2 km) model of NWAG's area including flows around the Faroes.

Phase I

Phase I modelling was a short (4 month) test run over a limited domain; the work finished in January 2001. Results were encouraging and helped to identify potential improvements to the model.

Figure 2 illustrates current velocities generated by the model in the deeper layer in the Faroe Bank Channel

Figure 2. NWAG Model: Deep -water current vectors in Faroe Bank channel

Phase II

Phase II aims to produce a 2.5-year combined validation/production run of the model using NWAG’s full fine-grid domain (2 km resolution) as shown in figure 1. It will produce inter-comparison statistics for 16 NWAG stations and other sites maintained by international institutions. The first half of Phase II finished in September 2002 and inter-comparisons showed improvement over Phase I.

Beyond phase II

Assuming the proposed phase II work is successful, future developments are likely to include extending the modelled database from the proposed 2.5 years to cover a longer period, and examining the potential to operate the model in forecast mode to assist future operations.