Water forecasts and data assimilation

Abstract

The Waterforecast (http://www.waterforecast.com) has been operated since year 2001 providing a daily 5-day forecast on physical parameters such as wave climate, water levels, currents, salinity and temperature. However, also biogeochemical parameters have been included in the forecasts since 2001 providing similar 5-day forecasts for parameters such as dissolved oxygen and chlorophyll-a. Until now, data assimilation has not been carried out systematically. However, through different projects (MARCOAST (http://gmes-marcoast.com) and BALANCE (http://balance-eu.org)) new assimilation techniques have been implemented and tested improving the performance of the model forecast. Data assimilation has been carried out for physical parameters on basin to global scales for more than a decade and is now also advancing to regional systems forecasting, revealing some of the problems of data assimilation in frontal areas. Also, different modeling groups around the Baltic Sea work on improving biogeochemical model results by assimilation or by using more simple techniques attempting to improve forecasts of especially cyano-bacteria in the Baltic Sea. We have now successfully combined advanced data assimilation and water forecasting of both satellite images and profile measurements carrying out hindcast modeling of oxygen concentrations in the Baltic Sea and transition area and on-line assimilation of satellite images of SST and chlorophyll-a providing updated and improved forecasts on the state of the Baltic Sea, the North Sea and interconnecting seas.