Assimilating HF radar currents to improve coastal predictions

Abstract

The improved Drift Forecasting in Coastal Waters (IDFCW) project, between Proudman Oceanographic Laboratory (POL) and British Marine Technology (BMT), is underway. Some of the questions addressed within this project are: in what way can the assimilation of HF-radar currents into models improve forecasts of surface sea state and currents in areas dominated by tidal currents? Can it lead to more effective responses in spill forecasting and Search and Rescue (SAR) operations? In order to answer thjese questions, we are carrying a series of experiments using the POL Coastal Ocean Modelling System (POLCOMS) and a set of observations provided by the POL Coastal Observatory. These include the 12-16MHz WERA phased HF radar array, providing the assimilated data set, as well as ADCP data from two mooring points and observations from spatial surveys and ferrybox lines providing the validation. The study examines the effect of assimilating hourly, 4 km resolution surface currents from the HF radar in different tide and wind conditions throughout 2006 in a 1.8 km Irish Sea 3-d model setup. Our assessment of the system capability will be presented