NOAA/CIRES Twentieth Century Global Reanalysis Version 2c
d131002
<p style="margin: 0px; padding: 0px"> 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. </p> <p> 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. </p> <p> <font color="red"> 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 <a href="https://www.esrl.noaa.gov/psd/data/gridded/20thC_ReanV2c/opportunities.html" target="_blank">opportunities for improvement</a> for additional information. </font> </p> <p> 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. </p>
dataset
https://gdex.ucar.edu/datasets/d131002/
protocol: https
name: Dataset Description
description: Related Link
function: information
https://gdex.ucar.edu/datasets/d131002/dataaccess/
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name: Data Access
description: Related Link
function: download
climatologyMeteorologyAtmosphere
dataset
revision
2021-03-30
REANALYSIS MODELS
revision
2025-10-03
20CR > NOAA-CIRES 20th Century Reanalysis
revision
2025-10-03
EARTH SCIENCE > ATMOSPHERE > ALTITUDE > GEOPOTENTIAL HEIGHT
EARTH SCIENCE > ATMOSPHERE > ALTITUDE > PLANETARY BOUNDARY LAYER HEIGHT
EARTH SCIENCE > ATMOSPHERE > ALTITUDE > TROPOPAUSE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC CHEMISTRY > OXYGEN COMPOUNDS > ATMOSPHERIC OZONE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE > GRAVITY WAVE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE > SEA LEVEL PRESSURE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE > SURFACE PRESSURE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC RADIATION > HEAT FLUX
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC RADIATION > LONGWAVE RADIATION
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC RADIATION > SHORTWAVE RADIATION
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > AIR TEMPERATURE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > MAXIMUM/MINIMUM TEMPERATURE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > POTENTIAL TEMPERATURE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > UPPER AIR TEMPERATURE
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR INDICATORS > HUMIDITY
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR INDICATORS > TOTAL PRECIPITABLE WATER
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR PROCESSES > EVAPORATION
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR PROCESSES > EVAPOTRANSPIRATION
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR PROCESSES > SUBLIMATION
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > SURFACE WINDS
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > UPPER LEVEL WINDS
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > WIND DYNAMICS > CONVECTION
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > WIND DYNAMICS > VERTICAL WIND VELOCITY/SPEED
EARTH SCIENCE > ATMOSPHERE > CLOUDS > CLOUD MICROPHYSICS > CLOUD LIQUID WATER/ICE
EARTH SCIENCE > ATMOSPHERE > CLOUDS > CLOUD PROPERTIES > CLOUD BASE PRESSURE
EARTH SCIENCE > ATMOSPHERE > CLOUDS > CLOUD PROPERTIES > CLOUD FREQUENCY
EARTH SCIENCE > ATMOSPHERE > CLOUDS > CLOUD PROPERTIES > CLOUD TOP PRESSURE
EARTH SCIENCE > ATMOSPHERE > PRECIPITATION > PRECIPITATION RATE
EARTH SCIENCE > BIOSPHERE > VEGETATION > VEGETATION COVER
EARTH SCIENCE > BIOSPHERE > VEGETATION > VEGETATION SPECIES
EARTH SCIENCE > HUMAN DIMENSIONS > ENVIRONMENTAL GOVERNANCE/MANAGEMENT > LAND MANAGEMENT > LAND USE/LAND COVER CLASSIFICATION
EARTH SCIENCE > LAND SURFACE > SOILS > SOIL MOISTURE/WATER CONTENT
EARTH SCIENCE > LAND SURFACE > SURFACE RADIATIVE PROPERTIES > ALBEDO
EARTH SCIENCE > LAND SURFACE > SURFACE THERMAL PROPERTIES > SKIN TEMPERATURE
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > SURFACE ROUGHNESS
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > SEA SURFACE TEMPERATURE
EARTH SCIENCE > OCEANS > SEA ICE > ICE DEPTH/THICKNESS
EARTH SCIENCE > OCEANS > SEA ICE > ICE EXTENT
EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > SNOW/ICE > SNOW COVER
EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > SNOW/ICE > SNOW DEPTH
EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > SNOW/ICE > SNOW WATER EQUIVALENT
EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > SURFACE WATER > SURFACE WATER PROCESSES/MEASUREMENTS > RUNOFF
revision
2025-10-03
-180.0
180.0
90.0
-90.0
1850-12-31T2100+00
2014-12-31T2100+00
publication
2015-03-16
annually
Creative Commons Attribution 4.0 International License
None
pointOfContact
NSF NCAR Geoscience Data Exchange
name: NSF NCAR Geoscience Data Exchange
description: The Geoscience Data Exchange (GDEX), managed by the Computational and Information Systems Laboratory (CISL) at NSF NCAR, contains a large collection of meteorological, atmospheric composition, and oceanographic observations, and operational and reanalysis model outputs, integrated with NSF NCAR High Performance Compute services to support atmospheric and geosciences research.
function: download
pointOfContact
2025-10-09T01:20:53Z