20th Century Reanalysis
Using a state-of-the-art data assimilation system and surface pressure observations, the Twentieth Century Reanalysis Project is generating a six-hourly, four-dimensional global atmospheric dataset spanning 1851 to 2014 to place current atmospheric circulation patterns into a historical perspective.
20th Century Reanalysis and PSD:
Until recently, the earliest reanalysis product started from 1948, leaving many important climate events such as 1930's dust bowl
droughts uncovered. To expand the coverage of global gridded reanalyses,
the 20th Century Reanalysis Project is an effort led by PSD and the
CIRES at the University of Colorado to produce
a reanalysis dataset spanning the entire twentieth century,
assimilating only surface observations of synoptic pressure,
monthly sea surface temperature and sea ice distribution. The
observations have been assembled through international cooperation
under the auspices of the Atmospheric Circulation Reconstructions over the Earth initiative (ACRE), and working
groups of GCOS and WCRP. The Project uses an Ensemble Filter
data assimilation method which directly yields each six-hourly analysis as the most likely state of the global atmosphere,
and also estimates uncertainty in that analysis. This
dataset provides the first estimates of global tropospheric variability spanning 1851 to 2012 at
six-hourly resolution (V2c). Fields from 1851 to 1860 are a first attempt at this period and will be improved in future versions [Opportunities for Improvement]. Fields from 1861 to 2014 are most relevant for climate and weather studies. There are two previous versions of the 20CR.
Recreating the Knickerbocker Storm of 1922: One of the deadliest snowstorms in U.S. history was the Knickerbocker Storm, a slow- moving blizzard that occurred on January 27-29, 1922 in the upper South and Middle Atlantic states. This storm was named after the collapse of the Knickerbocker Theater in Washington, D.C. shortly after 9 p.m. on January 28. The movie theater's flat roof collapsed under the weight of 28 inches of wet snow, bringing down the balcony and a portion of the brick wall and killing 98 people, including a Congressman. An arctic air mass had been in place across the Northeast for several days before the storm, and Washington had been below freezing since the afternoon of January 23. The storm formed over Florida on January 26 and took three days to move up the Eastern Seaboard. Snow reached Washington and Philadelphia by noon on January 28 and continued into the morning of January 29. Winds gusting up to 50 mph created blizzard conditions, and heavy drifting blocked roads for days. Railroad lines between Philadelphia and Washington were covered by at least 36 inches of snow, with drifts as high as 16 feet. Figure above presents data from the 20th Century Reanalysis Project's three- dimensional reanalysis of conditions at 7p.m. on January 28, 1922. With data like this available for the entire 20th century, climate researchers hope to improve their models so that they can more confidently predict regional weather trends for the future.
* Source: SCIDAC Review, Spring, 2008 http://www.scidacreview.org/0801/pdf/climate.pdf.
Examples of 20th Century Reanalysis data on NOAA's Science on a Sphere
The Science on a Sphere project has available 3 animations created using the 20th Century V2 precipitable water data. They are the Galveston hurricane of September 1900, the 1917 La Nina transitioning to the 1918 El Niño and 1902-1903 (where the location of the Discovery ship is marked). Users can view these on a 'Science on a Sphere' exhibit and can download the animations from the Science on a Sphere 20th Century Reanalysis webpage.
Analysis and Plotting Tools
Please use these pages below to plot the 20th Century Reanalysis Version 2c and 2 of the data. Additional tools will be forthcoming.
Clicking on graphics will show full sized images of the example plots. Clicking on the plotting tool descriptions,e.g., 1) Monthly Composites, 2) Monthly/Seasonal Google Earth Interface, 3) Sub-Daily Average Composites, and 4) Monthly/Seasonal Google Earth Interface will show respective plotting tool pages. You can also use the PSD Search and Plot page. This is less flexible but can access all the data. Search for dataset(s) 'NOAA-CIRES 20th Century...'.
Version 2: Maps/Cross-Sections
 |  |  |
| Monthly Composites | Monthly/Seasonal Google Earth Interface | Daily Composites |
 |  |  |
| Search for and Plot All Fields | Sub-Daily Composites | WRIT: Mapping Tool |
Version 2: Timeseries
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| Monthly Mean Time Series Extraction/Plotting page | Daily Time Series Extraction page |
 |  |
| WRIT: Timeseries Comparison Webpage | 20Cth V2 Derived Climate Indices |
Version 2: Other Products
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| WRIT: Trajectory Web Page | 20Cth V2 Monthly Mean Products |
 |  |
| Vertical Profiles | Time by Lat/Lon |
Dataset Information and Access:
Data and more information can be found at the following sites
V2c
- NOAA/ESRL PSD 20th Century Reanalysis version 2c data documentation page.
- NCAR 20th Century Reanalysis version 2c data documentation page.
- NERSC Science Gateway to 20th Century Reanalysis version 2c selected ensemble member fields.
V2
- NOAA/ESRL PSD 20th Century Reanalysis version 2 data documentation page.
- NCAR 20th Century Reanalysis version 2 data documentation page.
- The Centre for Environmental Data Archival now has a copy of the 20CR dataset.
- NERSC Science Gateway to 20th Century Reanalysis version 2 selected ensemble member fields.
A subset of the V2 dataset is now available via the Earth System Grid Federation (ESGF) NOAA/ESRL Node (where CMIP5 data is also available).The URL is http://hydra.fsl.noaa.gov/esgf-web-fe/.
Click on "Search" and you can find it by using the search term "reanalysis".
V1
Other
Other Useful Webpages:
Other Useful Webpages:
- PSD Monthly Climate Indices
Plot, analyze and obtain various ocean and atmospheric indices including the the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO) the SOI and many others.
Acknowledgment (V2c):
The NOAA-CIRES 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.
Papers using the NOAA-CIRES Twentieth Century Reanalysis Project version 2c dataset are requested to include the following text in their acknowledgments: "Support for the Twentieth Century Reanalysis Project version 2c dataset is provided by the U.S. Department of Energy, Office of Science Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office
Acknowledgment (V2):
The Twentieth Century Reanalysis Project used resources of the National Energy Research Scientific Computing Center managed by Lawrence Berkeley National Laboratory and of the Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory, which are supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 and Contract No. DE-AC05-00OR22725, respectively.
Papers using the Twentieth Century Reanalysis Project dataset are requested to include the following text in their acknowledgments: "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."
References:
- 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, http://dx.doi.org/10.1175/BAMS-87-2-175.
- 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. Brönnimann, M. Brunet, R.I. Crouthamel, A.N. Grant, P.Y. Groisman, P.D. Jones, M. Kruk, A.C. Kruger, G.J. Marshall, M. Maugeri, H.Y. Mok, Ø. Nordli, T.F. Ross, R.M. Trigo, X.L. Wang, S.D. Woodruff, and S.J. Worley, 2011: The Twentieth Century Reanalysis Project. Quarterly J. Roy. Meteorol. Soc., 137, 1-28. http://dx.doi.org/10.1002/qj.776
- Shoji Hirahara, Masayoshi Ishii, and Yoshikazu Fukuda, 2014: Centennial-Scale Sea Surface Temperature Analysis and Its Uncertainty. J. Climate,27, 57-75. doi: http://dx.doi.org/10.1175/JCLI-D-12-00837.1
- 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, http://dx.doi.org/10.1175/1520-0493(2004)132<1190:RWRUED>2.0.CO;2
Feedback
We would greatly appreciate feedback on its use; in the classroom, for presentations or for research. Mail to PSD.data at (esrl.psd.data@noaa.gov).20th Century Reanalysis
Data Access at PSD
- FTP: Data is available via anonymous ftp. For specific details, see the data documentation. Go to "pressure or monolevel" link and there is a list of variables. Or, go to "search and plot" and search for dataset NOAA-CIRES 20th Century Reanalysis V2c and the variable(s) you would like. Additional ftp help is also available.
- OPEnDAP: Data can be read directly via OPEnDAP. See the data documentation: File naming, OPeNDAP name from the data documentation webpage. We also have help on OPeNDAP and the applications that use it (GrADS, NCL...).
Data Access at NERSC
- OPEnDAP: NetCDF-4 files for every member of selected variables are available from the NERSC Science Gateway.
- wget: GRIB files for every member are available from the NERSC Science Tape Gateway.
Data Access at NCAR
- wget: GRIB files or netCDF for the ensemble mean and ensemble standard deviation are available from NCAR.
Dataset Creation Details
- Information about the input pressure level data, what was used to prescribe the boundary conditions, the model run, and similar details can be found on the dataset doc pages for 20CRV2 and 20CRV2c.
Acknowledgment (V2c):
The NOAA-CIRES 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.
Papers using the NOAA-CIRES Twentieth Century Reanalysis Project version 2c dataset are requested to include the following text in their acknowledgments: "Support for the Twentieth Century Reanalysis Project version 2c dataset is provided by the U.S. Department of Energy, Office of Science Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office
Acknowledgment (V2):
The Twentieth Century Reanalysis Project used resources of the National Energy Research Scientific Computing Center managed by Lawrence Berkeley National Laboratory and of the Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory, which are supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 and Contract No. DE-AC05-00OR22725, respectively.
Papers using the Twentieth Century Reanalysis Project dataset are requested to include the following text in their acknowledgments: "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."
References:
- 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, http://dx.doi.org/10.1175/BAMS-87-2-175.
- 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. Brönnimann, M. Brunet, R.I. Crouthamel, A.N. Grant, P.Y. Groisman, P.D. Jones, M. Kruk, A.C. Kruger, G.J. Marshall, M. Maugeri, H.Y. Mok, Ø. Nordli, T.F. Ross, R.M. Trigo, X.L. Wang, S.D. Woodruff, and S.J. Worley, 2011: The Twentieth Century Reanalysis Project. Quarterly J. Roy. Meteorol. Soc., 137, 1-28. http://dx.doi.org/10.1002/qj.776
- Shoji Hirahara, Masayoshi Ishii, and Yoshikazu Fukuda, 2014: Centennial-Scale Sea Surface Temperature Analysis and Its Uncertainty. J. Climate,27, 57-75. doi: http://dx.doi.org/10.1175/JCLI-D-12-00837.1
- 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, http://dx.doi.org/10.1175/1520-0493(2004)132<1190:RWRUED>2.0.CO;2
Related Data Sources:
- Reanalyses.org: Reanalysis Intercomparison and Observations Wiki
- GCOS Surface Pressure Working Group
- International Surface Pressure Databank (ISPD)
- International Comprehensive Ocean-Atmosphere Data Set
- National Climatic Data Center
- International Best Track Archive for Climate Stewardship
- NCEP_NCAR Reanalysis Project
- National Centers for Environmental Prediction
- National Center for Atmospheric Research
- Atmospheric Circulation Reconstructions over the Earth initiative (ACRE)
- IEDRO Weather Data Rescue Organization