Jochen-horstmann Drifter Christian-schmid

Using complex computer models and modern radar technology, researchers explore ocean currents. These researchers are now able to generate increasingly precise forecasts – something from which rescue teams and scientists alike can benefit. What moves us: Where the Water Flows

Insitute of Coastal Research
Coasts, Climate and Society

Computer Simulations

The entire system in focus

Symbol image german bay

Data from ESA (MERIS), processed by Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung GmbH

The HZG researchers compute and investigate the diverse interrelationships using computer simulations on high performance computers in order to understand them. The aim is to produce a model of the entire coastal system that is as detailed and significant as possible. Fundamental physical principles and the equations of motion derived from Newtons basic laws of motion provide the basis for these virtual models.

Among other things, they depict the dynamism of ocean circulation patterns or air currents in the atmosphere. The modelling focuses on the entire system, which ranges from the river basins and marginal seas to the continental margins and includes both the oceans and the atmosphere. Observation data – obtained by the COSYNA coastal measurement system, for example – helps to improve the model outcomes and can be included in the calculations with the aid of mathematical methods. Mankind also has a steadily growing influence on events: we fish, build wind parks in the sea and pollute the coasts.

Why computer models are important

Some of the models permit prognoses based on sound knowledge. One such example involves forecasts of how the sea currents in the German Bight will develop over the short term. They provide important information for shipping: if a person falls overboard, for instance, the simulations make it possible to estimate where the currents may carry it. In the event of an oil spill, they can indicate the direction in which the oil slick is moving and whether mud flats or islands are threatened.

Climate change impacts can be projected and possible changes can be assessed. Could storms in our latitudes become heavier and more severe over the coming decades as a result of man-made climate change? How significantly could the sea level rise in certain regions and which coastal regions would be most endangered? The Northern German Coast and Climate Office already provides information through different online tools and information products on possible changes and its impact on northern Germany.

Experts are also using computer simulations to try to estimate whether the towers of offshore wind parks mix up the surrounding water to such an extent that they are changing the current conditions in the North Sea. Even though assertions like these always carry some uncertainty, the HZG researchers continue to endeavour to minimise these imponderables – partly by improving calculation models, but also by acquiring a deeper understanding of the complex, interlinked processes.

Look into the past in order to learn for the future

Symbol image windmills

Photo: Fotolia/dell

Another purpose of the simulations is to look into the past in order to learn for the future. Measurement data for the North Sea dating back more than 150 years is available. Corresponding models are combined in a dataset known as ‘"coastDat“’. Statistics on how certain weather or current conditions develop can be established using coastDat and it serves thereby the planning of new offshore wind parks and its construction, for instance, providing information on the best month to service wind turbines based on the weather statistics.

The Institute of Coastal Research is cooperating with a wide range of national and international research partners in order to gain the most comprehensive understanding of the coastal system. Among other things, it is involved in the CliSAP Cluster of Excellence and works closely with authorities, higher education establishments and research facilities – including the Max Planck Institute for Meteorology and the University of Hamburg – as part of the ‘KlimaCampus Hamburg’ network. There is also a broad cooperation arrangement behind the COSYNA coastal measurement network coordinated by the HZG. Those involved include the Federal Maritime and Hydrographic Agency (BSH), the Alfred Wegener Institute at the Helmholtz Centre for Polar and Marine Research (AWI) and several regional authorities and institutes at the universities of Bremen, Oldenburg and Kiel. All in all, more than 100 scientists collaborate to run the COSYNA network.