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
| Dataset | Start Date1 | End Date1 | Climo Available | Climate Data Guide (NCAR) |
|---|
| NCEP/NCAR Reanalysis | Jan 1948 | near present | 1981-2010 | Here |
| NCEP/DOE Reanalysis II | Jan 1979 | Dec 2012 | 1981-2010 | Here |
| 20CR | Jan 1871 | Dec 2010 | 1981-2010 | Here |
| NCEP CFSR | Jan 1979 | Dec 2011 | 1981-2010 | Here |
| MERRA | Jan 1979 | Dec 2011 | 1981-2010 | Here |
| ERA-Interim | Jan 1979 | Feb 2013 | 1981-2010 | Here |
|
Observational Datasets
| Dataset | Variables | Start Date1 | End Date1 | Climo Available | Climate Data Guide (NCAR) |
|---|
| U of Delaware 3.01 | temperature, precipitation | Jan 1900 | Dec 2010 | 1981-2010 | guide |
| CRU_TS 3.1 | 2m temperature | Jan 1901 | Dec 2009 | 1981-2010 | N/A |
| GHCN-CAMS | 2m temperature | Jan 1948 | near present | 1981-2010 | N/A |
| HadSLP2 | SLP | Jan 1871 | near present (full is 1850) | 1981-2010 | N/A |
| GPCP V2 | precipitation | Jan 1979 | near present | 1981-2010 | Here |
| HadISST 1.1 | SST | Jan 1870 | near present | 1981-2010 | Here |
| NOAA Reconstructed Land Precip | precipitation | Jan 1948 | near present | 1981-2010 | Here |
| WASWinds | 10m zonal, meridional winds | Jan 1950 | Dec 2011 | 1981-2010 | Here |
|
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 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.
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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.
