Japanese Reanalysis - JRA-55
Access
UNRESTRICTED
Free for scientists at JMA (after application at JMA):
RESTRICTED only accessable in ZMAW net or via CliSAP login What does that mean?
Data access via file system:
/data/icdc/reanalyses/jra-55/
Description
JRA-55 is a global reanalysis and the successor of the JRA-25 reanalysis of the Japanese Weather Service "Japan Meteorological Agency" (JMA) and replaces it completely. The aim of the reanalysis was to produce a high-quality and homogeneous dataset suitable for climate research and the study of multi-decadal variability. The data set begins in 1958 and is ongoing.
For the various meteorological variables of the JRA-55, a more sophisticated numerical analysis and weather prediction (NWP) system was implemented, and further observations were included that were not yet available for JRA-25. Many of the shortcomings of JRA-25 reanalysis have been improved or eliminated in JRA-55. The table on the right (Ebita et al., 2011) compares data assimilation methods and constraints of JRA-25 and JRA-55.
ICDC currently offers a selection of meteorological parameters in two different versions.
The selected parameters at different altitude levels were produced by Dr. Christian Franzke. The data set has a daily resolution for the period from 1958 to 2017 and is globally available on a regular 1.25 ° x 1.25 ° grid and, depending on the parameters, in different heights.
In addition, monthly mean values of surface values of various parameters are available, that were prepared by ICDC.
Parameters
| Name | Description | Unit | Number of Levels |
|---|---|---|---|
| var1 | Air Pressure | Pa | 1 |
| var2 | Pressure reduced to mean sea level | Pa | 1 |
| var13 | Surface air potential temperature | K | 1 |
| var11 | Surface air temperature | K | 1 |
| var33 | Surface 10m zonal wind | m/s | 1 |
| var34 | Surface 10m meridional wind | m/s | 1 |
| var18 | Surface 2m dew point depression | K | 1 |
| var51 | Surface 2m specific humidity | kg/kg | 1 |
Coverage, spatial and temporal resolution
Period and temporal resolution:
- 1958-01-01 00:00 +0000 to 2013-01-01 00:00 +0000
- Monthly
Coverage and spatial resolution:
- Global
- Spatial Resolution: 1.25° x 1.25°, Gaussian Grid
- Geographic longitude: 180.0°W to 180°E
- Geographic latitude: 90.0°S to 90.0°N
- Dimension: 288 columns x 145 rows
Format:
- NetCDF
Data quality
Details on the data assimilation and prediction system, as well as some early results of the quality of JRA-55 can be found in Ebita et al. 2007.
Contact
At JMA:
Institute: Climate Prediction Division, Global Environment and Marine Department, Japan Meteorological Agency
Email: jra (at) met.kishou.go.jp
At ICDC:
Name: Annika Jahnke-Bornemann
Institute: ICDC
References
Websites:
http://jra.kishou.go.jp/JRA-55/index_en.html
Literature:
Ebita, A., S. Kobayashi, Y. Ota, M. Moriya, R. Kumabe, K. Onogi, Y. Harada, S. Yasui, K. Miyaoka, K. Takahashi, H. Kamahori, C. Kobayashi, H. Endo, M. Soma, Y. Oikawa, and T. Ishimizu, 2011: The Japanese 55-year Reanalysis "JRA-55": an interim report, SOLA, 7, 149-152.
Onogi, K., J. Tsutsui, H. Koide, M. Sakamoto, S. Kobayashi, H. Hatsushika, T. Matsumoto, N. Yamazaki, H. Kamahori, K. Takahashi, S. Kadokura, K. Wada, K. Kato, R. Oyama, T. Ose, N. Mannoji and R. Taira (2007) : The JRA-25 Reanalysis. J. Meteor. Soc. Japan, 85, 369-432.
