Use of the Supercomputer

Changes in the environment caused by human activities may lead to exceeding the Earth’s resilience capability, resulting in irreversible climatic and environmental changes. To prevent this to happen, it is necessary to make future projections and to take appropriate countermeasures.

The Earth system that surrounds us, including the atmosphere, oceans, and rivers, is based on complex physical, chemical, and biological processes. We need to reproduce a virtual earth environment using computers incorporating the latest knowledge of these various processes, examine climatic and environmental changes, and make detailed temporal and spatial projections.

In order to support research on global environmental model calculations, the Center for Global Environmental Research (CGER) in cooperation with the Environmental Information Department at NIES has established a supercomputer system and offers it to researchers both within and outside NIES.

Specification of the Supercomputer

The supercomputer (vector processor) was installed to elucidate and project phenomena related to global environmental change. The first supercomputer was introduced in fiscal year 1991 and it was updated to its seventh version in March 2020.

The core of the current supercomputer system is an ultra-high-speed 256 VE (Vector Engine) vector processor (NEC SX-Aurora TSUBASA A511-64, peak performance: 622.8 TFLOPS). The vector processor has an ultra-high-speed vector calculator and a large-capacity memory necessary for large-scale calculations such as global environmental simulations. In addition, a scalar processor (HPE Apollo 2000, peak performance: 86.0 TFLOPS) and a large-capacity file system with an effective capacity of 22 PB have been introduced to meet various calculation needs and the need for storing a huge amount of calculation data. These systems are available via an internal network connecting the various research centers.

SX-Aurora TSUBASA (Vector processing computer)

Apollo 2000 (Scalar processing computer) and Parallel Storage

Number of Nodes	256 VE nodes
Total Number of CPU Cores	2048
Peak Vector Performance	622.8 TFLOPS (622.8 trillion floating point calculations per second) （2048 CPU cores × 304 GFLOPS）
Central Memory Capacity	12 TB
Internode Crossbar Switch (IXS) Transfer Rate (GB/s)	12.5 GB/s × 2 (bidirection)
OS	CentOS 7
Compiler	NEC SDK for VE
Libraries	NetCDF，GFD Cyber Library (DCL), etc.
Tools	GTOOL, GrADS, etc.

Implementation research

The supercomputer implementation research themes are selected after consideration by the “Supercomputer Usage Committee”, which is composed of experts from within and outside of NIES. The research results are published in the NIES Supercomputer Annual Report and Monograph Report in order to introduce a broad range of global environmental research using the Supercomputer system and to facilitate information exchange among users.

Research Programs and Representatives in FY 2024

Climate change studies by development of Earth-Human system modelsTokuta YOKOHATA (NIES)

Development of a climate model and downscaling of climate projectionsNagio HIROTA (NIES)

A study of chemical constituent transport and climate change over the whole depth of the atmosphere using chemistry-climate modelsYosuke YAMASHITA (NIES)

Assessment of the impact of SLCFs on climate and regional environment using future emission scenarioDaisuke GOTO (NIES)

Climate Change Impacts and Nutrient Management in Enclosed Water AreaHironori HIGASHI (NIES)

Estimation of sources/sinks of atmospheric constituents/particles using NICAMYosuke NIWA (NIES)

Development of a data assimilation method for advanced air pollution forecastDaisuke GOTO (NIES)

Numerical study on cloud systems using NICAM Masaki SATOH (The University of Tokyo)

A numerical experiment on varieties of climates of terrestrial planets with taking exoplanets into consideration: climate regime diagrams of land planetsMasaki ISHIWATARI (Hokkaido University)

Archives of reserch programs

Annual Report

Monograph Report

Example of research results

The supercomputer system is used for research on global environmental phenomena and problem. The system is utilized in order to reproduce and project complex natural phenomena in the atmosphere and ocean by long-term simulations covering the whole world, and to accumulate, process and analyze information on the environment and living organisms from the past to the present.

We have carried out numerical simulations on how the earth’ surface temperature changes in the future caused by global warming, based on the individual emission scenarios estimated by the Intergovernmental Panel on Climate Change (IPCC). We have also carried out other important simulations and future projections in a wide range of fields such as the behavior of radioactive emissions into the sea caused by the accident at Fukushima Daiichi Nuclear Power Plant.