Seasonal predictions can be made because the interaction of different climate components always shifts the chaotic behavior of the atmosphere to a certain state. For example, soil, ocean or sea-ice all store water and heat from the atmosphere and release it at a later time, sometimes even in other places. They are the long-term memory of the atmosphere in a sense and make it possible to predict processes even on longer time scales. Therefore, seasonal predictions require a coupled climate system, as it is available with the MPI-M Earth System Model.
In order to carry out a seasonal forecast, it is also necessary to determine the initial values of the coupled climate system. The knowledge of the current state of land, atmosphere, ocean and sea-ice is crucial. Therefore, the model at UHH is fed with measurements and data directly derived from measurements, using special methods in such a way that model physics is brought very close to the current climate state. From this point on, the prediction is started.
The earth system model of MPI-M and the regulations of the initial fields are combined and integrated into the operational workflow at DWD. Thus, new seasonal climate forecasts can be created and made available every month. The signed agreement formalizes the cooperation between DWD, UHH and MPI-M for the German Climate Forecast System.
Prof Johanna Baehr
Center for Earth System Research and Sustainability
Institute of Oceanography
Phone: +49 40 42838-7736
Dr Kristina Fröhlich
Phone: +49 69 8062-2429
Dr Wolfgang Müller
Max-Planck-Institut für Meteorologie
Phone: +49 40 – 41173 370