European Centre for Medium-Range Weather Forecasts
He was head of research at the European Centre for Medium-Range Weather Forecasts from 1975 to 1981 and then director until 1990; then director of the Max Planck Institute for Meteorology in Hamburg. He became a recipient of the Milutin Milankovic Medal in 1996. He is now a senior research fellow at the Environmental Systems Science Centre in the University of Reading.