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JRA-25 is a second generation reanalysis product. The model and data assimilation are from the operational system in April 2004. It was the first reanalysis to assimilate wind profiles around tropical cyclones deduced from best-track data, resulting in improved tropical cyclone analysis in a global context. In addition, low-level (stratus) cloud decks along the western subtropical coasts of continents are also better simulated, improving radiation budgets in these regions. A primary goal of JRA-25 is to provide a consistent and high-quality reanalysis dataset for climate research, monitoring, and operational forecasts, especially by improving the coverage and quality of analysis in the Asian region. Note: JRA-25 has been superseded by the JRA-55 reanalysis, a 3rd generation product.

Key Strengths

Key Strengths

Long time series of the global precipitation is the best among the other second generation reanalyses

Assimilate wind profiles around tropical cyclones

Low-level cloud along the subtropical western coast of continents is well simulated

Key Limitations

Key Limitations

Does not account for satellite biases. Can affect trend; large temperature biases in stratosphere

CO2 held constant for all 25 years

Cold bias in lower stratosphere; Dry bias over Amazon

Please cite data sources, following the data providers' instructions
Suggested Data Citation
Dataset DOIs
Hosted Climate Index Files
Usage Restrictions

Research only; No redistribution

Key Figures

Annual temperature range of 2-meter temperature (C) from JRA25. (Climate Data Guide; D. Shea)

Other Information

Earth system components and main variables
Type of data product

Years of record
Data time period extended
No, data set not being extended
Sub-daily, Monthly
Input Data
Vertical Levels:
Missing Data Flag
Spatially complete
Ocean or Land
Ocean & Land
Spatial Resolution

1.125x1.125/2.5x2.5; 0.4 hPA top

Model Resolution (reanalysis)

T106, 40 levels

Data Assimilation Method
Model Vintage (reanalysis)


Key Publications
Not available...