NCAR Resarch Data Archive logo

NCEP/NCAR Global Reanalysis Products, 1948-continuing


This historical dataset is recommended for ancillary use only and not as a primary research dataset. It has likely been superseded by a newer, improved dataset.


Products from NCEP/NCAR Reanalysis Project (NNRP or R1) are archived in this dataset. The resolution of the global Reanalysis Model is T62 (209 km) with 28 vertical sigma levels. Results are available at 6 hour intervals. Although the initial plan is to reanalyze the data for a 40-year period (1957-1996), production has gone back to 1948 and going forward continuously. Future plans call for rerunning the entire period as next generation models are ready.

There are over 80 different variables, (including geopotential height, temperature, relative humidity, u- and v- wind components, etc.) in several different coordinate systems, such as 17 pressure level stack on 2.5 by 2.5 degree grids, 28 sigma level stack on 192 by 94 Gaussian grids, and 11 isentropic level stack on 2.5 by 2.5 degree grid. They are organized as different subgroups in the archive. In addition to analyses, diagnostic terms (for example: radiative heating, convective heating) and accumulative variables (like precipitation rate) are present. The input observations are archived with quality and usage flags in WMO BUFR format. Most of the project outputs are stored in WMO GRIB format. Other files, such as restart files and zonal statistics, are saved in IEEE format.

Some special periods are analyzed more than once to provide data for special research studies. For example, a special run of 1979 was made excluding most satellite inputs. This run could be used for evaluating the impact of satellite data on the analysis. During the TOGA COARE experiment period, special runs of reanalysis model without experimental data are archived under the TOGA COARE directory.

For details and problems, see NCEP/NCAR Reanalysis TOGA COARE. Monthly means are on line at ds090.2. The R1 forecasts are in ds090.1 dataset.

Temporal Range:
1948-01-01 00:00 +0000 to 2024-07-01 06:00 +0000 (Entire dataset) Period details by dataset product
Air Temperature Albedo Atmospheric Pressure Measurements Atmospheric Stability
Cloud Base Pressure Cloud Frequency Cloud Top Pressure Convergence
Dew Point Temperature Evaporation Geopotential Height Gravity Wave
Heat Flux Humidity Hydrostatic Pressure Ice Extent
Incoming Solar Radiation Land Use/Land Cover Classification Longwave Radiation Maximum/Minimum Temperature
Outgoing Longwave Radiation Potential Temperature Precipitation Rate Pressure Tendency
Runoff Sea Level Pressure Sea Surface Temperature Shortwave Radiation
Skin Temperature Snow Water Equivalent Soil Moisture/Water Content Streamfunctions
Surface Pressure Surface Roughness Surface Winds Temperature Tendency
Total Precipitable Water Tropopause Upper Air Temperature Upper Level Winds
Vegetation Species Vertical Wind Velocity/Speed Vorticity Wind Shear
GRIB parameter table: HTML | XML
Vertical Levels:
See the detailed metadata for level information.
Data Types:
Grid ,  Platform Observation
Spatial Coverage:
Longitude Range: Westernmost=180W Easternmost=180E
Latitude Range: Southernmost=90S Northernmost=90N Detailed coverage information
Data Contributors:
National Centers for Environmental Prediction, National Weather Service, NOAA, U.S. Department of Commerce
Kistler, R., E. Kalnay, W. Collins, S. Saha, G. White, J. Woollen, M. Chelliah, W. Ebisuzaki, M. Kanamitsu, V. Kousky, H. van den Dool, R. Jenne, and M. Fiorino, 2001: The NCEP-NCAR 50-Year Reanalysis: Monthly Means CD-ROM and Documentation Bull. Amer. Meteor. Soc., 82, 247-267.

Kalnay, E., M. Kanamitsu, R. Kistler, W. Collins, D. Deaven, L. Gandin, M. Iredell, S. Saha, G. White, J. Woollen, Y. Zhu, M. Chelliah, W. Ebisuzaki, W. Higgins, J. Janowiak, K.C. Mo, C. Ropelewski, J. Wang, A. Leetmaa, R. Reynolds, R. Jenne, and D. Joseph, 1996: The NCEP/NCAR 40-year reanalysis project Bull. Amer. Meteor. Soc., 77, 437-471.

Total Volume:
4.15 TB (Entire dataset) Volume details by dataset product
Data Formats:
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.