From sound simulations to accurate climate diagnoses

Nature is unpredictable, or is it? Together with IBM, the German Climate Computing Center (DKRZ) is shaking up this paradigm. As a central service facility for scientific climate research, the DKRZ is pursuing the question of how the global climate will develop in the future. By using the most modern IT architecture, it is constantly advancing our knowledge of the environment. Infinite potential climate scenarios are created and analyzed here using high performance computers. In this process, the simulations are meant to contribute to developing suitable measures for adequately addressing climate change challenges. With the goal of being able to successfully intervene, scientists are researching the influence that humans have on our increasingly changing world. The status report of the UN’s IPCC [Intergovernmental Panel on Climate Change], which appears regularly every few years, is prepared based on computer-supported climate simulations that are being performed on the computers at the DKRZ, among others. The report summarizes current scientific opinions on climate change and thus establishes the basis for appropriate action on a political level.

Exorbitant data volumes and computing power
Whether on land, in the water or on ice: Researchers the world over are working feverishly to analyze climate data. Samples are being taken, surveys are being performed, and the results recorded. However, this data alone does not mean much. Only by comparing it with climate simulations developments and trends become understandable on a global scale. For such climate simulations the best and most modern supercomputers are required. Their performance directly impact the accuracy of the forecasts for the future climate changes on our planet. Not only exorbitant volumes of data have to be processed for research purposes, it has to be stored and retrieved over the long term. The requirements of the DKRZ for its data archive are very high due to their importance as a central resource for earth system research. Research results stored there are used by scientists from around the world. Intelligent networking makes it possible to pool global knowledge. In addition to the constantly growing data volumes, the demand for computing power and the data archive is also on the rise. With the most modern and powerful systems from IBM, DKRZ is now equipped to face this challenge.

Coordinating and implementing a superlative project
In order to create even higher quality and more accurate climate simulations, the DKRZ decided to install one of the most powerful super computers available on the market. The HLRE 2 (High Performance Computer for Earth System Research) built using an IBM POWER6 cluster. To optimally use the resources and to adapt the customers’ simulation programs to the new IT architecture, IBM first performed an application benchmark. With the help of the POWER6 cluster, DKRZ was able to achieve a total throughput rate 60 times greater than the previous model. The increased performance directly impacts the quality of the forecasts because they enable considerably more of the processes that occur in our environment to be reproduced. Furthermore, the data archive had to be enlarged and modernized. This was the first time in Germany that IBM introduced the data storage solution HPSS (High Performance Storage System) – an innovative technology that was co-developed by IBM. Within only five months the project of superlatives was able to be put into action. At the same time the DKRZ was moving into a new building, both the POWER6 system and the HPSS were installed. In a matter of just a few weeks, technicians managed to build the POWER6 system with more than 260 servers and countless racks. IBM laid several kilometers of wires and developed the basis for water cooling the system. Once IBM had finished installing the super computer, it proceeded with installing the HPSS.
Like POWER6, the hardware used in the HPSS is also from IBM. However the set up of the data archive is mainly a service; storage systems of this magnitude are unique. That is why IBM initially determined the precise requirements of the DKRZ during numerous workshops and thereby developed suitable implementation strategies. Since it was necessary to transfer 32,000 magnetic tapes without having to copy a byte IBM developed a special software to migrate the data as quickly as possible from the old to the new system. The inventory data was migrated with the help of the software within just two weeks; without it, this would have taken years. As a basis for this migration IBM technicians created a directory of the old tapes in the new digital archive. The tapes can be read using the customized software. Once the data is accessed, they are unobtrusively re-written for the user in the HPSS format without delay. To benefit from synergy effects, the HPSS is integrated into the new super computer. Due to the additional configuration as an independent system, it can be used above and beyond its service life. Ulf Garternicht, Systems department manager at DKRZ: “The new archive solution now enables us to manage the enormous data volumes that climate researchers are obtaining on increasingly faster computers. The outstanding scalability and high-performance integration in the POWER6 cluster from IBM were the deciding factors in selecting the HPSS System.” IBM maintains the entire solution on site and the company’s know-how and expertise are available to the DKRZ as part of a five-year agreement.

Regional, national, global: improved forecasts for climate changes
Today, the DKRZ manages a considerably higher data volume than was ever possible with the previous system. Furthermore, the HPSS offers the necessary storage capacity to record processes from the complex climate and earth system with increasingly realistic as well as highly developed numerical models. With 60-times more power than the predecessor model, the POWER6 system opens up completely new opportunities for the DKRZ. Dr. Joachim Biercamp, Applications department manager at DKRZ: “The accuracy of climate simulations is heavily dependent on the available computing power. The new computer enables us to record considerably more processes and smaller-scale phenomena than ever before.” With a peak output of more than 150 TeraFlops, which is more than 150 billion computing operations per second, the HLRE 2 ranks among the world’s largest super computers used for scientific and research purposes. The entire system is operated from electricity generated by renewable energy. The new solution from the super computer and the data archive enables us to better understand climatic events and environmental processes. Due to the enormous computing power, the climate model has a higher spatial resolution and contains more processes which previously were only able to be parameterized inaccurately. With the aid of the archived data, developments and future tendencies can be understood easier and be prognosticated more profound. With this new knowledge researchers are developing and building suitable strategies to slow climate change. This successful symbiosis between scientific expertise at the DKRZ and highly modern IBM technology is therefore helping us to better understand the complex processes of our environment, protect it better, and to preserve it as a home to all living things.