Reanalysis and Observational Datasets and Variables Available on the WRIT Monthly Composite Mapping Page

Reanalyses and observational datasets available on the page are listed in the tables that follow. For more information and discussion of various atmospheric and oceanic reanalyses, see the "Reanalysis Intercomparison and Observations Wiki" (http://reanalyses.org). This wiki includes references/citations and a detailed reanalyses comparison table. Different reanalysis datasets have different pressure levels output so you may need to consider that when differencing variables. Datasets are produced at differing spatial resolutions. Plot differences are computed by interpolating the lower resolution dataset of the two being compared to the resolution of the higher resolution and subtracting. Anomalies are based on the climatology from each reanalyses dataset separately. Variable units have been changed to be consistent so the datasets can easily be compared.

Dataset Availability. More data may be available at the source.

Reanalyses Datasets
DatasetStart Date1End Date1Climo AvailableClimate Data Guide (NCAR)
NCEP/NCAR Reanalysis Jan 1948near present1981-2010Here
NCEP/DOE Reanalysis IIJan 1979Dec 20121981-2010Here
20CRJan 1871Dec 20121981-2010Here
NCEP CFSRJan 1979Dec 20111981-2010Here
MERRAJan 1979Dec 20111981-2010Here
ERA-InterimJan 1979Feb 20131981-2010Here
Observational Datasets
DatasetVariablesStart Date1End Date1Climo AvailableClimate Data Guide (NCAR)
U of Delaware 3.01temperature, precipitationJan 1900Dec 20101981-2010guide
CRU_TS 3.12m temperatureJan 1901Dec 20091981-2010N/A
GHCN-CAMS2m temperatureJan 1948near present1981-2010N/A
HadSLP2SLPJan 1871near present (full is 1850)1981-2010N/A
GPCP V2precipitationJan 1979near present1981-2010Here
HadISST 1.1 SSTJan 1870near present1981-2010Here
NOAA Reconstructed Land PrecipprecipitationJan 1948near present1981-2010Here
WASWinds10m zonal, meridional windsJan 1950Dec 20111981-2010Here

Variables

Pressure Level
geopotential height
zonal wind
meridional wind
omega
air temperature
specific humidity
relative humidity
Single Level
2m air temperature
SLP
precipitation rate
10m zonal wind
10m meridional wind
precipitable water
evaporation rate
SST/Skin Temperature
Users should enter "2m air temperature" for temperature and precipitation rate for precipitation in observed datasets.

1 Start and end dates reflect data on the WRIT pages and may not reflect what is available at the source.

  • NCEP/NCAR Reanalysis I 1948-present (NCEP R1 home page)

    This reanalysis was the first of its kind for NOAA. NCEP used the same climate model that was initialized with a wide variety of weather observations: ships, planes, RAOBS, station data, satellite observations and many more. By using the same model, scientists can examine climate/weather statistics and dynamic processes without the complication that model changes can cause. The dataset is kept current using near real-time observations.
  • NCEP/DOE Reanalysis II (1979-2011)

    NCEP produced a second version of their first reanalysis starting from the beginning of the major satellite era. More observations were added, assimilation errors were corrected and a better version of the model was used.
  • 20th Century Reanalysis (V2) 1871-2010 (20CR Home page)

    The 20th Century Reanalysis version 2 dataset contains global weather conditions and their uncertainty in six hour intervals from the year 1871 to 2010. Surface and sea level pressure observations are combined with a short-term forecast from an ensemble of integrations of an NCEP numerical weather prediction model using the recently developed Ensemble Kalman Filter technique to produce an estimate of the complete state of the atmosphere, and the uncertainty in that estimate. Additional observations and a newer version of the NCEP model that includes time-varying CO2 concentrations, solar variability, and volcanic aerosols are used in version 2. The long time range of this dataset allows scientists to examine better long time scale climate processes such as the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation as well as looking at the dynamics of historical climate and weather events. Verification tests have shown that using only pressure creates reasonable atmospheric fields up to the tropopause. Additional tests suggest some correspondence with observed variations in the lower stratosphere.
  • NCEP Climate Forecast System Reanalysis (CFSR): 1979-Dec 2009 (CFSR Home page.)

    The National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR) was completed over the 31-year period of 1979 to 2009 in January 2010. The CFSR was designed and executed as a global, high resolution, coupled atmosphere-ocean-land surface-sea ice system to provide the best estimate of the state of these coupled domains over this period. The current CFSR will be extended as an operational, real time product into the future.
  • NASA Modern Era Reanalysis for Research and Applications (MERRA): 1979-present (MERRA Home page)

    MERRA is a NASA reanalysis for the satellite era using a major new version of the Goddard Earth Observing System Data Assimilation System Version 5 (GEOS-5) produced by the NASA GSFC Global Modeling and Assimilation Office (GMAO). The Project focuses on historical analyses of the hydrological cycle on a broad range of weather and climate time scales and places the NASA EOS suite of observations in a climate context.
  • ERA-Interim: 1979-present (ERA-Interim Home page)

    ERA-Interim was originally planned as an 'interim' reanalysis in preparation for the next-generation extended reanalysis to replace ERA-40. It uses a December 2006 version of the ECMWF Integrated Forecast Model (IFS Cy31r2). It originally covered dates from 1 Jan 1989 but an additional decade, from 1 January 1979, was added later. ERA-Interim is being continued in real time. The spectral resolution is T255 (about 80 km) and there are 60 vertical levels, with the model top at 0.1 hPa (about 64 km). The data assimilation is based on a 12-hourly four-dimensional variational analysis (4D-Var) with adaptive estimation of biases in satellite radiance data (VarBC). With some exceptions, ERA-Interim uses input observations prepared for ERA-40 until 2002, and data from ECMWF's operational archive thereafter. An pen-access journal article describing the ERA-Interim reanalysis is now available from the Quarterly Journal of the Royal Meteorological Society and should be used as the citation.
  • U of Delaware surface temperature and precipitation (V3.01)

    See PSD's documentation and links
  • CRU_TS 3.1

    See BADC's Webpage
  • NASA GPCP V2

    See PSD's documentation for GPCP V2 monthly data
  • NOAA's Reconstructed Precipitation 1.0x1.0 land only

    See PSD's documentation for NOAA's Reconstructed Precipitation 1.0x1.0 land only
  • HadISST 1.1 Sea and Ice

    See the British Met Office BADC documentation.
  • NOAA ERSST

    NOAA Extended Reconstructed Sea Surface Temperature (ERSST) is a gridded 5x5 resolution SST dataset extending back into the 19th century.
  • WASWind

    Wave and Anemometer-based Sea Surface Wind (WASWind) from the U of Hawaii. It a gridded a sea surface wind dataset from ship observations of wind speed and wind wave height archived in the International Comprehensive Ocean-Atmosphere Data Set (ICOADS).
  • CPC Monthly Global Surface Air Temperature Data Set (GHCN-CAMS) surface temperature

    Dataset is a high resolution (0.5), globally gridded monthly air temperature dataset. See Documentation link from the IRI.. References are
    • Yun Fan and Huug van den Dool, 2008: A global monthly land surface air temperature analysis for 1948-present. J. Geophys. Res. DOI:10.1029/2007JD008470
    • Yun Fan and Huug van den Dool, 2004: Climate Prediction Center global monthly soil moisture data set at 0.5°resolution for 1948 to present. J. Geophys. Res., VOL. 109, D10102, doi:10.1029/2003JD004345.
  • HadSLP2

    Hadley Centre Sea Level Pressure dataset (HadSLP2) is a gridded 5x5 resolution SLP dataset extending back into the 19th century. After 2004, values are filled in using the NCEP/NCAR R1 dataset.
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