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NOAA/CIRES Twentieth Century Global Reanalysis Version 2c

| DOI: 10.5065/D6N877TW

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 It has likely been superseded by a newer, improved dataset.


The Twentieth Century Reanalysis Project, produced by the Earth System Research Laboratory Physical Sciences Division from NOAA and the University of Colorado Cooperative Institute for Research in Environmental Sciences, is an effort to produce a global reanalysis dataset spanning a portion of the nineteenth century and the entire twentieth century (1851 - near present), assimilating only surface observations of synoptic pressure. Boundary conditions of pentad sea surface temperature and monthly sea ice concentration and time-varying solar, volcanic, and carbon dioxide radiative forcings are prescribed. Products include 6-hourly ensemble mean and spread analysis fields on a 2 by 2 degree global latitude-longitude grid, and 3 and 6-hourly ensemble mean and spread forecast (first guess) fields on a global Gaussian T62 grid. Fields are accessible in yearly time series (1 file per parameter) and monthly synoptic time (all parameters per synoptic hour) files. This dataset provides the first estimates of global tropospheric variability spanning 1851 to 2012 at six-hourly resolution. Fields from 1851 to 1860 are a first attempt at this period and will be improved in future versions. Fields from 1861 to 2011 are most relevant for climate and weather studies.

20th Century Reanalysis Version 2c uses the same model as version 2 with new sea ice boundary conditions from the COBE-SST2 (Hirahara et al. 2014), new pentad Simple Ocean Data Assimilation with sparse input (SODAsi.2, Giese et al. 2015) sea surface temperature fields from through 2012, Daily High-Resolution-Blended Analyses for Sea Surface Temperature starting with 2013, and additional observations from ISPD version 3.2.9.

A low pressure bias in marine pressures from the US Maury Collection (Woodruff et al. 2005, Wallbrink et al. 2009, ) appears to have affected the resultant 20CR version 2c mass-related fields (e.g., pressure, geopotential height) from 1851 to about 1865. Please see opportunities for improvement for additional information.

The Twentieth Century Reanalysis Project version 2c used resources of the National Energy Research Scientific Computing Center managed by Lawrence Berkeley National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Version 2c is a contribution to the international Atmospheric Circulation Reconstructions over the Earth initiative. Support for the Twentieth Century Reanalysis Project is provided by the U.S. Department of Energy Office of Science (BER) and the NOAA Climate Program Office MAPP program.


RELEASE POLICY: Please use the citations listed below (See Publications section below) in any submitted publications using this dataset.

Additionally, papers using the Twentieth Century Reanalysis Project dataset are requested to include the following text in their acknowledgements:

Support for the Twentieth Century Reanalysis Project dataset is provided by the U.S. Department of Energy, Office of Science Innovative and Novel Computational Impact on Theory and Experiment (DOE INCITE) program, and Office of Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office.

Temporal Range:
1850-12-31 21:00 +0000 to 2014-12-31 21:00 +0000 (Entire dataset) Period details by dataset product
Air Temperature Albedo Atmospheric Ozone Cloud Base Pressure
Cloud Frequency Cloud Liquid Water/Ice Cloud Top Pressure Convection
Evaporation Evapotranspiration Geopotential Height Gravity Wave
Heat Flux Humidity Ice Depth/Thickness Ice Extent
Land Use/Land Cover Classification Longwave Radiation Maximum/Minimum Temperature Planetary Boundary Layer Height
Potential Temperature Precipitation Rate Runoff Sea Level Pressure
Sea Surface Temperature Shortwave Radiation Skin Temperature Snow Cover
Snow Depth Snow Water Equivalent Soil Moisture/Water Content Sublimation
Surface Pressure Surface Roughness Surface Winds Terrain Elevation
Total Precipitable Water Tropopause Upper Air Temperature Upper Level Winds
Vegetation Cover Vegetation Species Vertical Wind Velocity/Speed
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:
Cooperative Institute for Research in Environmental Sciences, University of Colorado
Physical Sciences Laboratory, Earth System Research Laboratory, OAR, NOAA, U.S. Department of Commerce
Giese, B. S., H. F. Seidel, G. P. Compo, and P. D. Sardeshmukh, 2016: An ensemble of ocean reanalyses for 1815-2013 with sparse observational input J. Geophys. Res. Oceans, 121, 6891-6910 (DOI: 10.1002/qj.776).

Hirahara, S., Ishii, M., and Y. Fukuda, 2014: Centennial-scale sea surface temperature analysis and its uncertainty J of Climate, 27, 57-75 (DOI: 10.1002/qj.776).

Compo, G. P., J. S. Whitaker, P. D. Sardeshmukh, N. Matsui, R. J. Allan, X. Yin,B. E. Gleason, R. S. Vose, G. Rutledge, P. Bessemoulin, S. Bronnimann, M. Brunet, R. I. Crouthamel, A. N. Grant, P. Y. Groisman, P. D. Jones, M. C. Kruk, A. C. Kruger, G. J. Marshall, M. Maugeri, H. Y. Mok, O. Nordli, T. F. Ross, R. M. Trigo, X. L. Wang, S. D. Woodruff, S. J. Worley, 2011: The Twentieth Century Reanalysis Project Quarterly J. Roy. Met. Soc., 137, 1-28 (DOI: 10.1002/qj.776).

G. P. Compo, J. S. Whitaker, and P. D. Sardeshmukh, 2008: The 20th Century Reanalysis Project. Proceedings of the Proceedings of the Third WCRP International Conference on Reanalysis, 28 January - 1 February 2008, WCRP, The University of Tokyo Japan. (DOI: 10.1002/qj.776).

Reynolds, Richard W., Thomas M. Smith, Chunying Liu, Dudley B. Chelton, Kenneth S. Casey, Michael G. Schlax, 2007: Daily High-Resolution-Blended Analyses for Sea Surface Temperature J. Climate, 20, 5473-5496 (DOI: 10.1002/qj.776).

Compo,G. P., J. S. Whitaker, and P. D. Sardeshmukh, 2006: Feasibility of a 100 year reanalysis using only surface pressure data Bull. Amer. Met. Soc., 87, 175-190 (DOI: 10.1002/qj.776).

Woodruff, S. D., H. F. Diaz, S. J. Worley, R. W. Reynolds, and S. J. Lubker, 2005: Early ship observational data and ICOADS Climatic Change, 73, 169-194 (DOI: 10.1002/qj.776).

Whitaker, J. S., G. P. Compo, X. Wei, and T. M. Hamill, 2004: Reanalysis without radiosondes using ensemble data assimilation Mon. Wea. Rev., 132, 1190-1200 (DOI: 10.1002/qj.776).

Total Volume:
10.84 TB (Entire dataset) Volume details by dataset product
Data Formats:
Related RDA Datasets:
NCEP Climate Forecast System Reanalysis (CFSR) 6-hourly Products, January 1979 to December 2010
NCEP Climate Forecast System Version 2 (CFSv2) 6-hourly Products
NOAA CIRES Twentieth Century Global Reanalysis Version 2
NOAA-CIRES-DOE Twentieth Century Reanalysis Version 3
The International Surface Pressure Databank version 3
ERA-20C Project (ECMWF Atmospheric Reanalysis of the 20th Century)
ERA-Interim Project
JRA-55: Japanese 55-year Reanalysis, Daily 3-Hourly and 6-Hourly Data
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.