Supercomputing in Climate Change - Computers must speed up to keep pace with climate change
Climate change cannot be excluded from the news media any more. Environmental disasters like melting poles, polluted oceans and temperatures in Europe of 20 degrees—in November–are new problems which scientists are confronted with. What caused the climate change? Who is to blame for the malaise? What are the consequences by which we will be affected personally? And what are the steps to be taken in order to prevent the total collapse of the climate?
published Deepwave Report 07 and HPC Wire 07
Questions upon questions – with nearly no concrete answers so far. That’s what climate researchers are wondering about. On their side are the mainframes, also known as supercomputers. DEEPWAVE started looking for the titans of Giga-, Tera- and Penta-devices and takes you along on a virtual journey on the data highway.
Computer simulations concerning the study of natural processes or the computation of natural disasters and effects upon the climate require more and more computing power. For such special requirements supercomputers of a special type are particularly suited—the array computers. A supercomputer of that kind is in the German Climate EDPC (Deutsches Klimarechenzentrum, DKRZ) in Hamburg. Located here is a NEC SX-6 with a total of 192 high-performance processors. It provides the staff members of the Geomatikum in Hamburg with the latest findings on every aspect of the climate. The DKRZ is a non-profit and non-commercial limited company and a service institution for the German climate and Earth System research. It doesn’t merely offer its computer as a service. Rather it provides researchers with information’s like data services and databases.
The main points of the contents of the calculations done at DKRZ comprise the simulation of single components of the actual climatic system—for example just of the atmosphere—to long-term simulations. Thereby the different system models of the Earth are coupled. Material cycles and interactions between atmosphere, ocean, biosphere, land surface, sea ice etc. are thereby integrated into the simulation process. The visualisation of model results is at the heart of the total task. “The DKRZ was built for climate purposes only. Thereby the computing power is exactly adjusted to the terms of reference”, says the technical director of the DKRZ, Michael Böttinger. “The simulation helps us to find causes and solutions—without to be in direct contact with the catastrophe”, he continues. This would also be a difficult venture in the case of a tsunami.
In the Stuttgart CAVE this is possible as well
Photo: HLRS
In the high-performance EDPC of Stuttgart (Hochleistungsrechenzentrum Stuttgart, HLRS) such kind of data can be processed with the help of a Cave. The term is the acronym for Cave Automatic Virtual Environment and refers to a room designed for the projection of a three-dimensional world of illusion of the virtual reality. These kinds of simulation are indispensable in climate research. “That kind of Cave enables us to better understand the causes and consequences, to take the right preventive measures and also to simulate special situations”, Mister Boenisch, chief engineer explains to us. The supercomputer in Stuttgart, a NEC SX-8, compared with the climate computer in Hamburg is designed for other scientific topics. Its higher performance characteristics of 72 nodes, 576 CPUs and 160 Terabyte/Share Disk (160,000 Gigabyte/Hard disk) therefore are also absolutely necessary. The NEC SX-8R processor with its 35.2 GigaFlops is the fastest array-processor worldwide. In comparison: A customary “good” home computer has a hard disk capacity of about 400 Gigabyte and a processor performance of about three to four Gigahertz.
Global warming of up to 4 degrees Celsius
In the forthcoming hundred years scientist expect a global warming of 2.5 to 4 degrees Centigrade – depending on the further development of the greenhouse-gas emissions. First results, which have been incorporated into the IPCC (Intergovernmental Panel on Climate Change) 4th Assessment Report, could be visualized by the DKRZ simulation.
20 years of climate change
Actually there is nothing new to it: Global warming is in full swing and the melting of the poles thereby causes a threatening rise of the sea level. After 20 years of climate change now a rethinking has begun as has been demanded by environmentalists for a long time. All over the world something is moving: Funds are allocated, scientists are forming special teams and the computing powers are increasing nearly with every hour – only in order to get climate change under control - in Germany most recently at Karlsruhe. Here the Hewlett Packard company has installed a simultaneous computer system with more than 3000 processors and a peak performance of over 15 TeraFlop per second (1 Teraflop/s = 1 trillion arithmetic operations per second). So, the system takes its place among the squad of the present five fastest mainframes in Germany. In this case as well one of the main topics is the climate. “Now those problems can be solved which formerly were regarded as insoluble concerning complexity and accuracy”, so the press office of the institute.
Capacities are constantly extended
Discussing solutions concerning the improvement of the problems of climate and slipping them into research: These are two intentions aimed at by the atmosphere researchers in Jülich. Jülich has the fastest mainframe in Europe and the Forschungszentrum Jülich (“Research Centre Jülich”, FZJ) is continuously extending its capacities in the field “climate”. The Jülich Blue Gene\L (JUBL) benefits of its 16384 parallel processors reaching a peak performance of 45 TeraFlops, i.e. 45 trillions arithmetic operations per second. Together with the Jülich Multi Processor (JUMP), installed next to it, a computer system has originated that reaches even place 13 in world ranking.
A better climate for China
The Jülich researchers now have presented the first results of two large-scale measurement campaigns in China. There, in the last summer they have investigated the most important causes for air pollution in the conurbation around Beijing and the Zhujioang delta. As to better air for the Olympic Games 2008 in Beijing the climate researchers recommend to use sulphur-free diesel fuels and to reduce the release of hydrocarbons from e.g. refineries. “We were mainly surprised by the high concentration of the hydroxyl radicals in Beijing”, explains Andreas Wahner, director at the Institut für Chemie und Dynamik der Geosphäre (“Institute for Chemistry and Dynamics of the Geosphere”) at the Forschungszentrum Jülich. This molecule is the “detergent of the atmosphere” and important for the degradation of pollutants. “We hadn’t expected this that way”, Werner continues. In fact, this detergent is degraded by nitrogen oxides, generated for example by exhaust emissions, at high levels of air pollution.”
A hall full of hard disks: The storage center of the DKRZ in Hamburg
Photo: DKRZ
Computer models should help to understand
Using computer models, the climate scientists would now like to simulate which conditions in the environment of Beijing have to be changed in order to improve the air quality in this mega-metropolis.
What’s it all about?
Tsunamis, hurricanes, floods, melting poles, polluted oceans in addition to overfishing are being analyzed and evaluated on the basis of these models. According to the IPCC Report, the climate change cannot be stopped any longer. EDPCs like Hamburg, Karlsruhe and Jülich focus attention on the climatic (complex of) problems and try to search for causes and solutions – to simulate.
Using computer models, the climate scientists would now like to simulate which conditions in the environment of Beijing have to be changed in order to improve the air quality in this mega-metropolis.
What’s it all about?
Tsunamis, hurricanes, floods, melting poles, polluted oceans in addition to overfishing are being analyzed and evaluated on the basis of these models. According to the IPCC Report, the climate change cannot be stopped any longer. EDPCs like Hamburg, Karlsruhe and Jülich focus attention on the climatic (complex of) problems and try to search for causes and solutions – to simulate.
With a glimpse ahead, this means that: The increasing memory and computing power will lead to ever more concrete and precise prognoses. As a result, supercomputing is becoming the focus of attention of climatology. However, simulations are merely a tool—a means to an end. At the end of the research chain are we—mankind. It’s true that we are able to simulate a better climate. But in order to guarantee a better and real climate for all inhabitants of Earth, we must act!