Global Terrestrial Hydrological Simulation System "Today's Earth"

JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EER20200

Subject Category: Space Technology

Responsible Representative: Kosuke Yamamoto, Space Technology Directorate I, Earth Observation Research Center
Contact Information: Today's Earth Research and Development Group(Z-watercnt@ml.jaxa.jp)
Members: Tomohiko Higashiuwatoko, Misako Kachi, Takuji Kubota, Ryosuke Kakuda, Kazuhiro Sakamoto, Kei Yoshimura, Kosuke Yamamoto

Abstract

Today's Earth is the global terrestrial hydrological simulation system to estimate various hydrological variables relating to the conditions of land surface and rivers utilizing satellite observation, developed under the joint-research of the JAXA and th University of Tokyo. In this project, long-term reprocessing of the past period of the system and development study of a future high-resolution simulation system for the global 10 km or more will be conducted on JSS.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

It is possible to perform large-scale processing that is difficult to execute on an EORC server, such as long-term reprocessing of past periods, the development of high-resolution simulation systems with a global resolution of 10 km or more, and large ensemble simulation.

Achievements of the Year

Following the previous fiscal year, in preparation for long-term retrospective reprocessing and the development of a high-resolution simulation system, we enhanced the spatial resolution of the Integrated Land Simulator (ILS), which is used in the Today's Earth system simulations, to a global 0.1-degree grid and conducted test runs with a view toward stable operational implementation.

.In addition, we examined linkage with the atmospheric ensemble data of NEXRA developed under a separate project code (R0201), and confirmed that land surface simulations can be executed using multiple ensemble members as input.

Publications

N/A

Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: N/A
Number of Processes: 100
Elapsed Time per Case: 70 Minute(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.02

Details

Please refer to System Configuration of JSS3 for the system configuration and major specifications of JSS3.

Computational Resources
System Name	CPU Resources Used (Core x Hours)	Fraction of Usage*2(%)
TOKI-SORA	40384.29	0.00
TOKI-ST	0.00	0.00
TOKI-GP	0.00	0.00
TOKI-XM	0.00	0.00
TOKI-LM	0.00	0.00
TOKI-TST	0.00	0.00
TOKI-TGP	0.00	0.00
TOKI-TLM	0.00	0.00

File System Resources
File System Name	Storage Assigned (GiB)	Fraction of Usage*2(%)
/home	1024.00	1.64
/data and /data2	102400.00	0.67
/ssd	30720.00	1.87

Archiver Resources
Archiver Name	Storage Used (TiB)	Fraction of Usage*2(%)
J-SPACE	16.81	0.05

*1: Fraction of Usage in Total Resources: Weighted average of three resource types (Computing, File System, and Archiver).

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.

ISV Software Licenses Used

ISV Software Licenses Resources
	ISV Software Licenses Used (Hours)	Fraction of Usage*2(%)
ISV Software Licenses (Total)	0.00	0.00

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.