JRA-55 - Japanese Reanalysis

Surface 2m dew point depression (2012/12)

Pressure reduced to mean sea level (2012/12) — Surface 2m dew point depression (2012/12)

JRA-55 Reanalysis Examples. Copyright: UHH/CEN/AJB
Surface 2m dew point depression (2012/12)	Pressure reduced to mean sea level (2012/12)
Surface 2m specific humidity (2012/12)	Surface air temperature (2012/12)
Surface 10m zonal wind (2012/12)	Surface 10m meridional wind (2012/12)

Topics

Access

RESTRICTED:

Get 6-hourly JRA-55 data from external sources: DIAS | NCAR

RESTRICTED: This link to the data set is only available for a restricted user group. The data set is only accessible in CEN/MPI net or accessible from external nets with a customer account. Please contact ICDC if you would like to access this data from outside the network.

Data access via file system: /data/icdc/reanalyses/jra-55/

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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 data set 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. See table in Ebita et al., 2011, that 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. From the original data, we also offer ground-level values of selected variables with a 6-hour resolution.

Last update of data set at ICDC: 2013, 2020

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Parameters

Parameters of the 6-hourly JRA.55 data set
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

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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

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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, see references.

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Contact

At JMA:

Climate Prediction Division, Global Environment and Marine Department, Japan Meteorological Agency

Email: jra (at) met.kishou.go.jp

Annika Jahnke-Bornemann
ICDC / CEN / University of Hamburg
E-Mail: annika.jahnke-bornemann"AT"uni-hamburg.de

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References

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. https://doi.org/10.2151/sola.2011-038
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.

Websites:

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Data citation, License, and Acknowledgments

Please cite the data as follows:

"Japan Meteorological Agency/Japan. 2013. JRA-55: Japanese 55-year Reanalysis, Daily 3-Hourly and 6-Hourly Data. Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory. "

and with the following acknowledgments:

Thanks to ICDC, CEN, University of Hamburg for data support.

License

Please see JRA-55 Website for detailed license information.

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