Atlas Computer Hardware Platform "Silicon Cube" Exhibition Diagram
The Earth Simulation Laboratory "Ring" will be initially built in Huairou Science City, Beijing on 20021.
202 1, the national key science and technology infrastructure numerical simulation device earth laboratory will be built soon. This is another big country in our country. Large-scale numerical calculation by supercomputer can reproduce the past of the earth, simulate the present of the earth and predict the future of the earth, so as to carry out targeted "earth experiments". This big country will also play an important role in the study of carbon neutrality and climate change. 65438+On February 24th, 2020, lasg established the first scientific research institution engaged in basic research on carbon neutrality in China. This facility will certainly provide scientific path and scientific support for China to achieve the peak of carbon dioxide emission and carbon neutrality.
What is the Earth System Simulation Laboratory?
Earth system simulator, also known as Earth simulation laboratory. The warming target of 1.5 or 2 proposed in the Paris agreement is calculated based on the earth system simulator. To put it simply, the simulated "Earth" is put into the laboratory to see how the natural system on the "Earth" responds to global warming caused by different carbon dioxide emissions, and finally determine an appropriate warming target. Note that the "earth" mentioned here is not a real earth, but a digital earth based on various physical and mathematical equations.
Gaseous air, liquid rivers, lakes and oceans, solid rocks, ice and snow, and evolving life forms on earth can be simply classified into five major circles: atmosphere, hydrosphere, cryosphere, lithosphere and biosphere. For thousands of years, people have felt the phenological changes in various circles and summarized the experience of nature. Based on the progress of science, we have been able to sum up some physical laws of natural changes and express them quantitatively with mathematical formulas. Further, these mathematical equations are written into computer code, and the corresponding code set of each circle layer is obtained, which is what we often say. For example, the atmospheric model is essentially the code set of atmospheric motion equation, continuous equation and thermodynamic energy equation.
Due to the complexity that everything in nature is closely related, it is impossible for people to include all mathematical equations in one code set at a time. In order to simplify the solution of the problem, people first construct a model to describe a single circle layer, and then organically combine all the models running independently through a "coupler". The coupler is like the exchange workshop of a huge factory, which exchanges material and energy between layers, thus coupling the modes of atmosphere, ocean and surface, and simulating the evolution process of nature to the greatest extent.
After getting this number "Earth", we can infer the changes of different circles of the earth by inputting the observation data at a certain moment and carrying out large-scale numerical calculation on the supercomputer, so as to reproduce the past of the earth, simulate the present of the earth and predict the future of the earth, so as to carry out targeted "Earth experiments".
Advantages of Atlas
We already know that the earth in reality is a complex system with closely related layers, and each layer contains many physical, chemical and biological processes. Therefore, the number of layers contained in an earth system model and the completeness of describing natural processes in each layer directly affect the authenticity of its simulation results. The development of the world numerical model is in the transitional stage from the climate system model to the earth system model. The former only considers the simulation of each layer of climate system such as atmosphere, ocean and land surface, while the latter further considers the carbon and nitrogen cycle and biogeochemical processes, which requires higher coupling between subsystems.
As the embodiment of comprehensive national strength, scientists all over the world are actively developing their own numerical models. For example, about 1 12 versions of climate models from 33 institutions around the world have registered for the ongoing Sixth International Coupled Model Comparison Program (CMIP6), which is the largest in history. Although there are so many numerical models in the world at present, most of them are climate system models. Only a few countries and regions such as the United States, Europe, Japan and China have submitted earth system models, including CAS-ESM2.0 developed by Institute of Atmospheric Physics, Chinese Academy of Sciences. It is worth mentioning that CAS-ESM is the core model software of Atlas. CAS-ESM2.0 has performed well in CMIP6 comparative test, and its simulation of global vegetation index, total primary productivity and other indicators ranks among the top in the world.
Atlas is located in Huairou Science City, Beijing. It is a special numerical simulation device for the earth system based on the numerical simulation software of each layer of the earth system, and its scale and comprehensive technical level rank among the top in the world. The construction of Atlas includes not only the main numerical simulation system of the earth system model, but also the regional high-precision (spatial resolution 1-3km) environmental simulation system, super simulation support and management system, support database and data assimilation and visualization system, earth science high-performance computing system and supporting civil facilities. After the completion of the atlas, it can provide a new paradigm for the scientific research of the earth system in China.
As a rising star of the global earth system simulator, Atlas adopts a numerical simulation software system with independent intellectual property rights in China, which has a complete, self-consistent and rigorous set of dynamics, physics, chemistry and ecological processes, and its resolution has reached the advanced level in the world. In addition, the interaction between layers is fully considered in multi-layer coupling. In the near future, Atlas will further couple space weather, continental glaciers and solid earth modules (such as the movement of the earth plate and its induced topographic changes, earthquakes, volcanic eruptions and so on). ), and the earth system simulation is extended to the fields of near space and solid earth.
Except for the support of software, all experiments are on paper if there is no suitable computer hardware to cooperate. The global simulation experiment is a super-calculation project with a wide time scale. The domestic chips used in Atlas provide super computing support for the ultra-complex earth system model. The "geoscience high-performance computer system" specially developed for Atlas has a computing peak value of not less than 1 5ppflops, and the computing power of1minute is equivalent to 7.2 billion people around the world using calculators continuously for four years. The whole system * * * has more than 3,000 water-cooled computing nodes, which are interconnected by HDR InfiniBand high-speed network, and the bandwidth is as high as 100Gbps. In addition, the storage space of the "Silicon Cube" database is 80PB, which can accommodate the collection data of about 13 national libraries to store the observation and simulation data of each circle.
A big country is a heavy weapon, where does the sword point?
Under the route of "carbon neutrality", we will vigorously develop new energy sources and various energy-saving and emission-reduction technologies to reduce carbon emissions, and at the same time promote the absorption of greenhouse gases in the atmosphere through "carbon fixation" such as afforestation, carbon capture and storage, so as to finally make the emission and absorption of CO2 equal, that is, realize "net zero emission" of carbon.
The accounting of greenhouse gases and the prediction of future temperature rise need to be supported by a simulation study of the earth system model with a complete circle, which is the advantage of Atlas. "Atlas" can consider all components of the earth system more comprehensively, especially the correlation simulation with the earth ecosystem and biogeochemical processes and their interaction with the climate system, and establish a clear relationship of "ecology-temperature-carbon dioxide concentration-carbon emission" on this basis, thus reducing the uncertainty of the relationship between the warming target of 1.5 and carbon emission.
In addition, under the climate background of global warming, reports on extreme weather events and their impact on human life have been increasing in recent 30 years, including strong typhoon, high temperature, rainstorm, drought and cold wave. The spatial scale of this extreme weather event is several kilometers and the time scale is within a few hours. In order to accurately capture these weather processes, it is necessary to improve the spatial resolution of the model, but it also means that it must carry a huge amount of calculation. After the completion of Atlas, equipped with high-performance computer hardware, it is possible to accurately predict extreme weather and climate events. Using a more refined and perfect earth system model, Atlas can capture more comprehensive prediction signals, thus improving the level of disaster prevention and early warning and enhancing China's disaster prevention and mitigation capabilities.
With the development of urbanization in China, various pollution problems have emerged. The problem of air pollution involves the complex emission process of the earth system, including global and regional transmission processes and urban-scale dynamic processes, which poses a great challenge to the simulation of air pollution. Simulating and reproducing these processes reasonably and completely is the key prerequisite for studying and controlling air pollution. Atlas has a regional high-precision air pollution model subsystem, which can simulate the emission, diffusion and chemical transformation of chemical components in the atmosphere. Moreover, Atlas has the ability of heavy metal simulation, coupled source identification and tracing technology, and can do a good job of "traceability" analysis of pollutants, thus improving the level of air pollution prediction and making the road of "beautiful China" ecological civilization stable and far-reaching.
In a word, the birth of "Atlas" will significantly enhance the overall innovation ability of geosciences in China and play an important role in solving major scientific problems such as disaster prevention and mitigation, environmental governance, sustainable development and ecological security.
Looking around the world, the United States, Japan, Europe and other developed countries have built special simulation devices for the earth system that combine software and hardware. For example, the National Center for Atmospheric Science (NCAR) of the United States has developed an excellent model of the earth system with its long-term world-leading numerical simulation device, so these countries have dominated the design and evaluation report of the Intergovernmental Panel on Climate Change (IPCC) climate change prediction experiment.
Changes are taking place and the future has arrived. With the publication of the national heavyweight "Atlas", China will no longer be in a passive position in the earth simulation science, especially in the academic field of global climate change, and we will be able to have more say in dealing with global climate change!
(Author: Chen Kexin and Zhao Yin, both doctors of lasg, pictures are provided by the Institute)