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JRA-55C: The Japanese 55-year Reanalysis Using Conventional Data Only

| DOI: 10.5065/D67H1GNZ

As a subset of the Japanese 55-year Reanalysis (JRA-55) project, the Meteorological Research Institute of the Japan Meteorological Agency has conducted a global atmospheric reanalysis that assimilates only conventional surface and upper air observations, with no use of satellite observations, using the same data assimilation system as the JRA-55. The project, named the JRA-55 Conventional (JRA-55C), aims to produce a more homogeneous dataset over a long period, unaffected by changes in historical satellite observing systems. The dataset is intended to be suitable for studies of climate change or multidecadal variability. The reanalysis period of JRA-55C is from November 1972 to December 2012. The JMA recommends the use of JRA-55 to extend JRA-55C back to January 1958.

The Data Support Section at NCAR has downloaded all JRA-55C data. The entire archive has been reorganized into single parameter time series, and model resolution data has been transformed to a regular Gaussian grid. The JRA-55C products are currently being made accessible to RDA registered users of JRA-55, and will appear incrementally via the Data Access tab.

Temporal Range:
1972-10-31 21:00 +0000 to 2013-01-01 00:00 +0000 (Entire dataset) Period details by dataset product
Usage Restrictions:

When accessing the JRA data, you agree to the following Terms and Conditions:

a. Conditions of use

  • Individual users must register their name, affiliation and email address with NCAR before access to datasets will be permitted.
  • The source of the datasets should be duly acknowledged in scientific and technical papers, publications, press releases and other communications regarding the datasets. Example: The dataset used for this study is from the Japanese 55-year Reanalysis Using Conventional Data Only (JRA-55C) project carried out by the Japan Meteorological Agency (JMA).
  • Individual users should provide JMA ( with a copy of their scientific or technical papers, publications, press releases or other communications regarding these datasets.

b. Disclaimer

  • Although JMA has taken the utmost care in creating the datasets, it assumes no responsibility regarding their reliability. JMA is not responsible for any damage that may result from their use.

c. Intellectual property

  • The intellectual property rights of the datasets belong exclusively to JMA.

The complete JMA and NCAR agreement for JRA-55 (and JRA-55C) may be viewed via the Documentation tab.

Air Temperature Atmospheric Stability Brightness Temperature Canopy Characteristics
Cloud Frequency Cloud Liquid Water/Ice Convergence Dew Point Temperature
Evaporation Evapotranspiration Geopotential Height Gravity Wave
Heat Flux Heat Flux Humidity Hydrostatic Pressure
Ice Extent Land Surface Temperature Land Use/Land Cover Classification Longwave Radiation
Maximum/Minimum Temperature Potential Temperature Precipitation Amount Precipitation Rate
Runoff Sea Level Pressure Shortwave Radiation Snow Depth
Snow Water Equivalent Soil Moisture/Water Content Soil Temperature Streamfunctions
Surface Pressure Surface Roughness Surface Winds Total Precipitable Water
Tropospheric Ozone Upper Air Temperature Upper Level Winds Vegetation Species
Vertical Wind Velocity/Speed Vorticity Water Vapor
GRIB parameter table: HTML | XML
Vertical Levels:
See the detailed metadata for level information.
Data Types:
Spatial Coverage:
Longitude Range: Westernmost=180W Easternmost=180E
Latitude Range: Southernmost=90S Northernmost=90N Detailed coverage information
Data Contributors:
Japan Meteorological Agency, Japan
Kobayashi, S., Y. Ota, Y. Harada, A. Ebita, M. Moriya, H. Onoda, K. Onogi, H. Kamahori, C. Kobayashi, H. Endo, K. Miyaoka, and K. Takahashi, 2015: The JRA-55 Reanalysis: General Specifications and Basic Characteristics J. Met. Soc. Jap., 93(1), 5-48 (DOI: 10.2151/jmsj.2015-001).

Kobayashi, C., H. Endo, Y. Ota, S. Kobayashi, H. Onoda, Y. Harada, K. Onogi and H. Kamahori, 2014: Preliminary results of the JRA-55C, an atmospheric reanalysis assimilating conventional observations only Sci. Online Lett. on the Atmos., 10, 78-82 (DOI: 10.2151/sola.2014-016).

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. Met. Soc. Jap., 85(3), 369-432 (DOI: 10.2151/jmsj.85.369).

Total Volume:
16.78 TB (Entire dataset) Volume details by dataset product
Data Formats:
Related RDA Datasets:
NOAA CIRES Twentieth Century Global Reanalysis Version 2
NOAA/CIRES Twentieth Century Global Reanalysis Version 2c
Japanese 25-year Reanalysis Project
Japanese 25-year Reanalysis Project, Monthly Means
ERA-20C Project (ECMWF Atmospheric Reanalysis of the 20th Century)
ERA-Interim Project
ERA-Interim Project, Monthly Means
ERA-Interim Project, Single Parameter 6-Hourly Surface Analysis and Surface Forecast Time Series
JRA-55: Japanese 55-year Reanalysis, Daily 3-Hourly and 6-Hourly Data
JRA-55: Japanese 55-year Reanalysis, Monthly Means and Variances
JRA-55C: Monthly Means and Variances
JRA-55AMIP: The Japanese 55-year Reanalysis AMIP-type Simulation
JRA-55AMIP: Monthly Means and Variances Including Diurnal Statistics
More Details:
View a more detailed summary of the data, including specific date ranges and locations by parameter
Metadata Record:
Data License:
Citation counts are compiled through information provided by publicly-accessible APIs according to the guidelines developed through the project. If journals do not provide citation information to these publicly-accessible services, then this citation information will not be included in RDA citation counts. Additionally citations that include dataset DOIs are the only types included in these counts, so legacy citations without DOIs, references found in publication acknowledgements, or references to a related publication that describes a dataset will not be included in these counts.