Computer simulations form a bridge between theory and experiment. As such, they have become of inestimable importance for scientific research. Simulations allow us to obtain insights and knowledge that has been previously inaccessible for physical, technical, financial or ethical reasons. Scientists use supercomputers to investigate the atmosphere and climate, biologically important substances, basic material properties and also chemical processes that cannot be recreated in the laboratory. In doing so, they profit from the continuously increasing computing capacity of the Jülich supercomputers, for example in the field of environment and climate research.
Simulation in Environmental Research
Physical and chemical processes in the atmosphere are very complex. Developing reliable climate models and forecasting the impacts of climate change are based on an understanding of these processes. In working on these tasks, climate researchers use supercomputers to simulate various scenarios incorporating experimental data. On the basis of such computer simulations, scientists can follow the path of pollutant and trace gases in the atmosphere, taking migration and degradation processes into consideration, and determine how atmospheric pollution influences climate. Atmospheric simulations can also be used to develop new detection methods for volcanic emissions.
Computing Power for Ensemble Simulations
In ensemble simulations, frequently applied in climate research, the same simulation can be started again and again, with the parameters being slightly modified in each case. This method detects uncertainties in the simulations, which is necessary because in reality the boundary conditions, such as the emission rates of greenhouse gases, frequently change during test periods. Climate simulations are an important tool for analysing "What would happen if ..." questions and can, for example, serve as a vital aid to decision-making for politicians.
The potential offered by ensemble simulations can only be exploited by supercomputers. The Jülich cluster system JUROPA is particularly well-suited for these types of calculations since this computer's large memory enables it to work with enormous volumes of data. This mainly comprises the data-intensive evaluation of long time series of satellite measurements and also the large volumes of input data for atmospheric chemistry and climate simulations.
Simulation Expertise in Dedicated Laboratories
Climate researchers receive support from the experts at the Simulation Laboratory Climate Science of the Jülich Supercomputing Centre (JSC) at Forschungszentrum Jülich. JSC has a number of these dedicated Simulation Laboratories (SimLabs). The laboratories are specialized in the simulation requirements of various scientific fields with respect to software, development of algorithms, and data transfer and storage.
For the geosciences, for example, there is the SimLab Terrestrial Systems. Supercomputers are also an important tool in this discipline. Researchers simulate terrestrial systems such as soils, agricultural land, and surface waters in order to better understand complex processes such as material and energy flows. Interactions between the groundwater, land surface, and atmosphere play an important role here. This concerns, for example, the hydrological cycle and the exchange of carbon. Simulations of these interactions do not only help us to understand component parts but rather the Earth system as a whole. This knowledge enables climate and weather to be predicted more accurately.
To achieve this, the supercomputers must handle enormous volumes of data. Since the computer systems are becoming ever more and more powerful, geoscientists can use ever higher spatial resolutions, longer simulation periods, and more realistic models in their applications. The experts at the SimLabs help them to adapt and optimize their models and applications for Jülich's supercomputers.