Skip to ContentSkip to Navigation
About usNews and EventsNews articles

Scalable algorithms for fully implicit ocean models

21 January 2011

PhD ceremony: Mr. J. Thies, 13.15 uur, Academiegebouw, Broerstraat 5, Groningen

Title: Scalable algorithms for fully implicit ocean models

Promotor(s): prof. A.E.P. Veldman

Faculty: Mathematics and Natural Sciences

 

Climate research is one of the disciplines which rely most heavily on numerical simulations. Experiments are tedious because of the diculty of scaling something as large as an ocean down to laboratory size. Observations are sporadic because research vessels are expensive and can only be at one location at a time. Satellites, on the other hand, are limited to observing the sea surface.

In this thesis we study innovative numerical techniques to make simulations of ocean ow easier. The focal point is the term ‘scalability’. We call an algorithm scalable if rening the computational grid leads to a linear increase of the required arithmetic operations. A computer program is called scalable if using more processors reduces the computing time accordingly.

The implicit approach that we propose is based on the solution of coupled systems of equations, whereas explicit models use simpler updates of the variables to get from one time step to the next. Our implicit approach can take unlimited time steps, which allows us to simulate much longer time intervals like ice ages -than explicit models can handle.

The ocean is a complex dynamical system which can be sensitive to small changes of parameters such as the temperature of the atmosphere. Traditional explicit models have to be restarted for each new scenario, whereas the implicit variant can step directly from one situation to the next, varying the parame¬ters slightly in every step (continuation). This leads to substantially increased eciency if one wants to test many scenarios.

 

Last modified:15 September 2017 3.41 p.m.

More news

  • 17 April 2019

    Why lightning often strikes twice

    In contrast to popular belief, lightning often does strike twice, but the reason why a lightning channel is ‘reused’ has remained a mystery. Now, an international research team led by the University of Groningen has used the LOFAR radio telescope to...

  • 16 April 2019

    Still going strong after four decades

    On March 29th professor of Applied Physics Jeff de Hosson was offered a farewell symposium, a few months after his official retirement date near the close of 2018. ‘But 29 March was the 100th birthday of Jan Francken, my predecessor.’ Besides, De Hosson...

  • 11 April 2019

    Ben Feringa in orbit around the Sun

    Dozens of minor planets that used to orbit the Sun anonymously were named by the International Astronomical Union on 6 April 2019. The asteroid that used to be known as ‘minor planet 12655’ was named after Prof. Ben Feringa, winner of the 2016 Nobel...