ENGINEERING
Thirty million hours of supercomputer time for space simulation
The monetary value of the computing time, granted free of charge, is about one million euros. Hermit, a Cray XE6 type computer, is one of the most powerful computers in Europe: it has 113,664 cores and performs over one million billion computations per second. The computer is located in Stuttgart, Germany.
In space research, the Finnish Meteorological Institute specialises in large-scale computer simulations modelling the behaviour of particles and electromagnetic fields in the vicinity of Earth and other bodies in the solar system. Simulation models are used, for example, to study processes involved in the origin of auroras. At the same time, methods are developed for predicting space weather. This will help, for instance, in protecting satellites against harmful particle showers.
Near space modelling requires the heaviest simulation resources
The Finnish Meteorological Institute’s newest space simulation, and the one requiring the most computing capacity, is Vlasiator designed for modelling near space. The name refers to the Vlasov equation, which the model uses to solve the velocity distributions of particles moving in space. In this way, the properties of plasma – or electrically conductive thin gas – moving within Earth’s magnetic field can be determined in more complex ways than by using the older simulation models, where the properties of plasma are described by means of density and temperature. Vlasiator is the world’s first simulation based on the Vlasov equation that can create a model of Earth’s entire magnetic field in three dimensions while at the same time creating particle distributions in six dimensions. Vlasiator has been developed with the help of a starting grant of nearly one million euros, awarded by the European Research Council in 2008. The project is also supported by the Academy of Finland
The Vlasiator model can also be run using the Finnish Meteorological Institute’s own supercomputers. However, the resources offered by PRACE, representing the highest performance in European computing, enable more accurate and faster modelling.
“With the computing time we have received, it’s like switching from a compact car to the world’s most powerful vehicle. Using these resources, we’ll be the first in the world to run a large-scale space simulation where even small-scale phenomena can be seen accurately for the first time ever. For example, we’ll see the properties of the shock wave surrounding the magnetosphere much more accurately than before. Our preliminary results have already shown that small-scale phenomena in plasma may play an important role in the formation of the shock. This may also affect the properties of plasma flowing into the magnetic field,” says Minna Palmroth, who leads the Vlasiator project.
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