Retirement Leo Maas

On 1 July 2021, our colleague Leo Maas officially retired. Although Leo will continue to come to the IMAU, this landmark offers a great opportunity to look back at his impressive academic career.

Leo studied Meteorology and Physical Oceanography at Utrecht University and graduated in 1981. After that he became PhD student of prof. Zimmerman at the IMAU. During this period, Leo studied tide-topography interactions in stratified seas, which resulted in a thesis that he successfully defended in 1987.

Already two years earlier, Leo and his wife Cathy moved to Texel, where Leo became postdoc, and later staff member, at the Netherlands Institute of Sea Research (NIOZ). Here, he worked on a variety of topics: tidal and frontal dynamics in the North Sea, the wind-driven ocean circulation, various kinds of ocean waves, tides in basins, etc. In 1992/1993 Leo and Cathy spent one year on Vancouver Island, where Leo worked with professor Garret, and in 2011 they spent half a year in Porto, where Leo worked with professor da Silva.

Leo’s research is quite broad as his UU-website demonstrates. But there is a common thread: he seeks connections between observations and fundamental theories to gain deep understanding of phenomena in fluids. For this, he also uses knowledge from, and contributes to the development of other fields: mathematics, physics, biology, ... One highlight is Leo’s work on observations (in a laboratory setting) and mathematical-physical analysis of internal wave attractors, which resulted in a publication in Nature (1997). Leo also initiated construction of new experimental facilities, such as the laboratory version of the ‘Helmholtz system’: a basin connected to a tidal sea by means of a small inlet. With this facility evidence was provided for Leo’s theory that multiple tidal solutions can occur for the same parameter values. Moreover, strong indications for a second theoretical aspect (chaotic tides) were found.

In 2007, Leo’s scientific achievements resulted in a professorship on ocean wave dynamics at Utrecht University. In 2017 he received the prize ‘Fellow of Euromech’.

Leo is further known for his efforts and achievements in education. During the years, he supervised many PhD, MSc and BSc students. Moreover, he taught the BSc course on Fluid Dynamics and the MSc course on Wave Attractors. Leo’s way of teaching and supervising is inspiring, he gives a lot of room to students, and at the same time provides them with lots of ideas.

As a person, Leo is kind, very approachable and he shows interest in everyone. When he and Cathy moved to Texel in 1985, they became very happy there and they never left. So, every time Leo had obligations at the university he travelled from Texel to Utrecht and vice versa, in total 6 hours. Over the years, they got three children. Leo is very energetic and likes to practice sports: badminton, mountain-biking, swimming etc. Moreover, he enjoys spending time with Cathy, reading books and listening to music.

Leo, it was and is great that we share(d) an office at the IMAU. You have contributed a lot to the institute, and many students (including myself) were partly shaped by you. On behalf of everyone, I wish you a great future and I personally hope that we maintain the contact and friendship that we have.

Huib de Swart