We thank Knut Barthel and Peter M. Haugan for useful discussions and constructive comments on the text. We would also thank Ernst Maier-Reimer and Uwe Mikolajewicz at the Max-Planck-Institut für Metereologie in Hamburg for providing us with the model and the data fields. The two anonymous reviewers also deserve thanks for constructive critiques and good suggestions that helped to improve the manuscript. This work has received support from The Research Council of Norway through Project No. 101533/720 and a grant of computing time (Program for Supercomputing).
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