Peter A. E. M. Janssen

The 2015 Fridtjof Nansen Medal is awarded to Peter A. E. M. Janssen for his outstanding contribution to the understanding of ocean wave physics and for his leadership in wind wave modelling.

Peter Janssen is a world leader in the theory and modelling of ocean waves. He was a major contributor to the third generation wave model (WAM), and modern wave forecasting is based on concepts first put forward during the development of WAM. It was under his leadership that a global version of WAM was first implemented operationally at the European Centre for Medium-range Weather Forecasts (ECWMF).

Janssen first highlighted the necessity of truly coupling ocean waves with the atmosphere and the oceans, and critically contributed to understanding the role of surface waves in momentum and energy transfer across the air-sea interface. Most importantly, he incorporated his fundamental research findings into a more general forecasting framework. His fundamental papers on the momentum transfer from wind to waves provided the parametric form of the wind input source term which is used currently in most wind wave forecast models around the world in both research and operations, including those at the leading operational centres. Janssen offered a theory for rogue waves in the ocean and took it all the way to the practical implementation, thus contributing to practical applications of wind wave theory. His contributions to wind wave physics are also critical for parameterisation of air-sea gas and particles exchanges and ocean biogeochemistry.

Peter Janssen’s insightful knowledge has provided a substantial basis for his highly successful developments of the leading-edge marine forecasting system in operation at the ECMWF. This underpins his ongoing recognition as an international leader in wind-wave research and development of the modern ocean forecast model systems.