The CRU JRA V2.1 dataset is a 6-hourly, land surface, gridded time series of ten meteorological variables produced by the Climatic Research Unit (CRU) at the University of East Anglia (UEA), and is intended to be used to drive models. The variables are provided on a 0.5 deg latitude x 0.5 deg longitude grid, the grid is near global but excludes Antarctica (this is same as the CRU TS grid, though the set of variables is different). The data are available at a 6 hourly time-step from January 1901 to December 2019.

The dataset is constructed by regridding data from the Japanese Reanalysis data (JRA) produced by the Japanese Meteorological Agency (JMA), adjusting where possible to align with the CRU TS 4.04 data (see the Process section and the ReadMe file for full details).

The CRU JRA data consists of the following ten meteorological variables: 2-metre temperature, 2-metre maximum and minimum temperature, total precipitation, specific humidity, downward solar radiation flux, downward long wave radiation flux, pressure and the zonal and meridional components of wind speed (see the ReadMe file for further details).

The CRU JRA dataset is intended to be a replacement of the CRU NCEP forcing dataset. The CRU JRA dataset follows the style of Nicolas Viovy's original CRU NCEP dataset rather than that which is available from UCAR. A link to the CRU NCEP documentation for comparison is provided in the documentation section.

If this dataset is used in addition to citing the dataset as per the data citation string users must also cite the following:

Harris, I., Osborn, T.J., Jones, P. et al. Version 4 of the CRU TS

monthly high-resolution gridded multivariate climate dataset.

Sci Data 7, 109 (2020). https://doi.org/10.1038/s41597-020-0453-3

Harris, I., Jones, P.D., Osborn, T.J. and Lister, D.H. (2014), Updated

high-resolution grids of monthly climatic observations - the CRU TS3.10

Dataset. International Journal of Climatology 34, 623-642.

Kobayashi, S., et. al., The JRA-55 Reanalysis: General Specifications and

Basic Characteristics. J. Met. Soc. Jap., 93(1), 5-48

https://dx.doi.org/10.2151/jmsj.2015-001