NOAA/CIRES Twentieth Century Global Reanalysis Version 2c

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.

To Access Resource:

Questions? Email Resource Support Contact:

  • Riley Conroy
    UCAR/NCAR - Research Data Archive

Temporal Range

  • Begin:  1850-12-31T00:00:00Z
    End:  2014-12-31T21:00:00Z


Resource Type dataset
Temporal Range Begin 1850-12-31T00:00:00Z
Temporal Range End 2014-12-31T21:00:00Z
Temporal Resolution N/A
Bounding Box North Lat N/A
Bounding Box South Lat N/A
Bounding Box West Long N/A
Bounding Box East Long N/A
Spatial Representation N/A
Spatial Resolution N/A
Related Links

Related Resource #1 : NOAA ESRL 20th Century Reanalysis Project Homepage

Related Resource #2 : Atmospheric Circulation Reconstructions over the Earth

Related Resource #3 : Summary of available global reanalysis dataset and collaboration space

Related Resource #4 : COBE SST2 and Sea-Ice dataset

Related Resource #5 : Access individual 20 CR v2 ensemble grids through the NERSC Gateway

Related Resource #6 : Access 20th CR v2c in NetCDF format at ESRL. Monthly and daily means are also available at ESRL

Additional Information N/A
Resource Format WMO_GRIB1 (Binary)
Standardized Resource Format GRIB
Asset Size 11170309 MB
Legal Constraints

Use of this dataset is subject to UCAR's Terms of Use, except that commercial use is generally not prohibited.

Access Constraints Registration on the RDA web site is a requirement for access to the data.
Software Implementation Language N/A

Resource Support Name Riley Conroy
Resource Support Email
Resource Support Organization UCAR/NCAR - Research Data Archive
Distributor NCAR Research Data Archive
Metadata Contact Name N/A
Metadata Contact Email
Metadata Contact Organization NCAR Research Data Archive

Author Compo, Gilbert P.
Whitaker, Jeffrey S.
Sardeshmukh, Prashant D.
Allan, Robert J.
McColl, Chesley
Yin, Xungang
Giese, Benjamin S.
Vose, Russell S.
Matsui, Nobuki
Ashcroft, Linden
Auchmann, Renate
Benoy, Mac
Bessemoulin, Pierre
Brandsma, Theo
Brohan, Philip
Brunet, Manola
Comeaux, Joseph
Cram, Thomas
Crouthamel, Richard
Groisman, Pavel Y.
Hersbach, Hans
Jones, Philip D.
Jonsson, Trausti
Jourdain, Sylvie
Kelly, Gail
Knapp, Kenneth R.
Kruger, Andries
Kubota, Hisayuki
Lentini, Gianluca
Lorrey, Andrew
Lott, Neal
Lubker, Sandra J.
Luterbacher, Jurg
Marshall, Gareth J.
Maugeri, Maurizio
Mock, Cary J.
Mok, Hing Y.
Nordli, Oyvind
Przybylak, Rajmund
Rodwell, Mark J.
Ross, Thomas F.
Schuster, Douglas
Srnec, Lidija
Valente, Maria Antonia
Vizi, Zsuzsanna
Wang, Xiaolan L.
Westcott, Nancy
Woollen, John S.
Worley, Steven J.
Publisher Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory
Publication Date 2015-03-16
Digital Object Identifier (DOI)
Alternate Identifier ds131.2
Resource Version N/A
Topic Category climatologyMeteorologyAtmosphere
Progress onGoing
Metadata Date 2024-03-24T15:05:02-07:00
Metadata Record Identifier edu.ucar.rda::ds131.2
Metadata Language eng; USA
Suggested Citation Compo, Gilbert P., Whitaker, Jeffrey S., Sardeshmukh, Prashant D., Allan, Robert J., McColl, Chesley, Yin, Xungang, Giese, Benjamin S., Vose, Russell S., Matsui, Nobuki, Ashcroft, Linden, Auchmann, Renate, Benoy, Mac, Bessemoulin, Pierre, Brandsma, Theo, Brohan, Philip, Brunet, Manola, Comeaux, Joseph, Cram, Thomas, Crouthamel, Richard, Groisman, Pavel Y., Hersbach, Hans, Jones, Philip D., Jonsson, Trausti, Jourdain, Sylvie, Kelly, Gail, Knapp, Kenneth R., Kruger, Andries, Kubota, Hisayuki, Lentini, Gianluca, Lorrey, Andrew, Lott, Neal, Lubker, Sandra J., Luterbacher, Jurg, Marshall, Gareth J., Maugeri, Maurizio, Mock, Cary J., Mok, Hing Y., Nordli, Oyvind, Przybylak, Rajmund, Rodwell, Mark J., Ross, Thomas F., Schuster, Douglas, Srnec, Lidija, Valente, Maria Antonia, Vizi, Zsuzsanna, Wang, Xiaolan L., Westcott, Nancy, Woollen, John S., Worley, Steven J.. (2015). NOAA/CIRES Twentieth Century Global Reanalysis Version 2c. Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory. Accessed 18 June 2024.

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