After undergraduate and MSc studies in astrophysics and theoretical physics he did a PhD in 1992 in coastal engineering at technical University Delft, specifically on ocean waves and ‘surf beat’. Then he worked at the University of Utrecht on the role of the ocean in the climate system, climbing the academic ladder from postdoc to associate prof. In 2009 He moved to the University of Reading, UK, to take on a professorship in Data Assimilation, leading the Data Assimilation Research Centre and the Data Assimilation Research at the National Centre for Earth Observation. Recently he partly joined the Colorado Sate University in Fort Collins, USA, as professor in Data Assimilation and Physical Oceanography. He has a joined position in Reading and in Fort Collins.