NCEP/NCAR Reanalysis Monthly Means and Other Derived Variables

We have transitioned the data files from netCDF3 to netCDF4-classic format on Monday Oct 20th, 2014.

Brief Description:

  • NCEP/NCAR Reanalysis Monthly Means and Other Derived Variables..

Temporal Coverage:

  • Daily and Monthly Values for 1948/01 - present.
  • Long term monthly means, derived from data for years 1981 - 2010.

Spatial Coverage:

  • T62 Gaussian grid (192x94)
  • 88.542N - 88.542S, 0E - 358.125E

Levels:

  • Surface or near the surface

Update Schedule:

  • Monthly
  • All variables are available except net longwave radiation and net shortwave radiation, which are updated sporadically

Download/Plot Data: (FTP Access)

These variables are forecasts valid 6 hours after the reference time. Archive parameters: File names are generally composed of variable abbreviations, averaging period and statistic. Averaging periods include "day" and "mon". Statistics include "mean", "ltm"(long-term mean), "inter.std" (interannual standard deviation). (variable).(averaging period).(statistic).nc

Variable Statistic Level Download File Create Plot/Subset
Air Temperature at 2 meters Monthly Mean 2m air.2m.mon.mean.nc plot
Air Temperature at 2 meters Monthly Long Term Mean 2m air.2m.mon.ltm.nc plot
Air Temperature at 2 meters Daily Long Term Mean 2m air.2m.day.1981-2010.ltm.nc plot
Air Temperature at 2 meters 4X Daily Long Term Mean 2m air.2m.4Xday.1981-2010.ltm.nc plot
Ice Concentration Monthly Mean Surface icec.sfc.mon.mean.nc plot
Ice Concentration Monthly Long Term Mean Surface icec.sfc.mon.ltm.nc plot
Ice Concentration Daily Long Term Mean Surface icec.sfc.day.1981-2010.ltm.nc plot
Ice Concentration 4X Daily Long Term Mean Surface icec.sfc.4Xday.1981-2010.ltm.nc plot
Potential evaporation rate Monthly Mean Surface pevpr.sfc.mon.mean.nc plot
Potential evaporation rate Monthly Long Term Mean Surface pevpr.sfc.mon.ltm.nc plot
Potential evaporation rate Daily Long Term Mean Surface pevpr.sfc.day.1981-2010.ltm.nc plot
Potential evaporation rate 4X Daily Long Term Mean Surface pevpr.sfc.4Xday.1981-2010.ltm.nc plot
Water runoff Monthly Mean Surface runof.sfc.mon.mean.nc plot
Water runoff Monthly Long Term Mean Surface runof.sfc.mon.ltm.nc plot
Water runoff Daily Long Term Mean Surface runof.sfc.day.1981-2010.ltm.nc plot
Water runoff 4X Daily Long Term Mean Surface runof.sfc.4Xday.1981-2010.ltm.nc plot
Specific humidity at 2 meters Monthly Mean 2m shum.2m.mon.mean.nc plot
Specific humidity at 2 meters Monthly long Term Mean 2m shum.2m.mon.ltm.nc plot
Specific humidity at 2 meters Daily long Term Mean 2m shum.2m.day.1981-2010.ltm.nc plot
4X Specific humidity at 2 meters Daily long Term Mean 2m shum.2m.4Xday.1981-2010.ltm.nc plot
Volumetric soil moisture (0-10 cm) Monthly Mean 0-10 cm soilw.0-10cm.mon.mean.nc plot
Volumetric soil moisture (0-10 cm) Monthly Long Term Mean 0-10 cm soilw.0-10cm.mon.ltm.nc plot
Volumetric soil moisture (0-10 cm) Daily Long Term Mean 0-10 cm soilw.0-10cm.day.1981-2010.ltm.nc plot
Volumetric soil moisture (0-10 cm) 4X Daily Long Term Mean 0-10 cm soilw.0-10cm.4Xday.1981-2010.ltm.nc plot
Volumetric soil moisture (10-200cm) Monthly Mean (ltm) 10-200cm soilw.10-200cm.mon.mean.nc plot
Volumetric soil moisture (10-200cm) Monthly Long Term Mean 10-200cm soilw.10-200cm.mon.ltm.nc plot
Volumetric soil moisture (10-200cm) Daily Long Term Mean 10-200cm soilw.10-200cm.day.1981-2010.ltm.nc plot
Volumetric soil moisture (10-200cm) 4X Daily Long Term Mean 10-200cm soilw.10-200cm.4Xday.1981-2010.ltm.nc plot
Skin Temperature Monthly Mean Surface skt.sfc.mon.mean.nc plot §
Skin Temperature Monthly Long Term Mean Surface skt.sfc.mon.ltm.nc plot §
Skin Temperature Daily Long Term Mean Surface skt.sfc.day.1981-2010.ltm.nc plot §
Skin Temperature 4X Daily Long Term Mean Surface skt.sfc.4Xday.1981-2010.ltm.nc plot §
Temperature Monthly Mean 0-10cm tmp.0-10cm.mon.mean.nc plot
Temperature Monthly Long Term Mean 0-10cm tmp.0-10cm.mon.ltm.nc plot
Temperature Daily Long Term Mean 0-10cm tmp.0-10cm.day.1981-2010.ltm.nc plot
Temperature 4X Daily Long Term Mean 0-10cm tmp.0-10cm.4Xday.1981-2010.ltm.nc plot
Temperature Monthly Mean 10-200cm tmp.10-200cm.mon.mean.nc plot
Temperature Monthly Long Term Mean 10-200cm tmp.10-200cm.mon.ltm.nc plot
Temperature Daily Long Term Mean 10-200cm tmp.10-200cm.day.1981-2010.ltm.nc plot
Temperature 4X Daily Long Term Mean 10-200cm tmp.10-200cm.4Xday.1981-2010.ltm.nc plot
Temperature Monthly Mean 300cm tmp.300cm.mon.mean.nc plot
Temperature Monthly Long Term Mean 300cm tmp.300cm.mon.ltm.nc plot
Temperature Daily Long Term Mean 300cm tmp.300cm.day.1981-2010.ltm.nc plot
Temperature 4X Daily Long Term Mean 300cm tmp.300cm.4Xday.1981-2010.ltm.nc plot
Maximum Temperature Monthly Mean 2m tmax.2m.mon.mean.nc plot
Maximum Temperature Monthly Long Term Mean 2m tmax.2m.mon.ltm.nc plot
Maximum Temperature Daily Long Term Mean 2m tmax.2m.day.1981-2010.ltm.nc plot
Maximum Temperature 4X Daily Long Term Mean 2m tmax.2m.4Xday.1981-2010.ltm.nc plot
Minimum Temperature Monthly Mean 2m tmin.2m.mon.mean.nc plot §
Minimum Temperature Monthly Long Term Mean 2m tmin.2m.mon.ltm.nc plot §
Minimum Temperature Daily Long Term Mean 2m tmin.2m.day.1981-2010.ltm.nc plot §
Minimum Temperature 4X Daily Long Term Mean 2m tmin.2m.4Xday.1981-2010.ltm.nc plot §
U-wind at 10 m Monthly Mean 10m uwnd.10m.mon.mean.nc plot
U-wind at 10 m Monthly Long Term Mean 10m uwnd.10m.mon.ltm.nc plot
U-wind at 10 m Daily Long Term Mean 10m uwnd.10m.day.1981-2010.ltm.nc plot
U-wind at 10 m 4X Daily Long Term Mean 10m uwnd.10m.4Xday.1981-2010.ltm.nc plot
V-wind at 10 m Monthly Mean 10m vwnd.10m.mon.mean.nc plot
V-wind at 10 m Monthly Long Term Mean 10m vwnd.10m.mon.ltm.nc plot
V-wind at 10 m Daily Long Term Mean 10m vwnd.10m.day.1981-2010.ltm.nc plot
V-wind at 10 m 4X Daily Long Term Mean 10m vwnd.10m.4Xday.1981-2010.ltm.nc plot

These variables are 6 hour averages starting at the reference time.

/* here */
Variable Statistic Level Download File Create Plot/Subset
Cloud forcing net longwave flux Monthly Mean Surface cfnlf.sfc.mon.mean.nc plot
Cloud forcing net longwave flux Monthly Long Term Mean Surface cfnlf.sfc.mon.ltm.nc plot
Cloud forcing net longwave flux Daily Long Term Mean Surface cfnlf.sfc.day.ltm.nc plot
Cloud forcing net longwave flux 4X Daily Long Term Mean Surface cfnlf.sfc.4Xday.ltm.nc plot
Cloud forcing net solar flux Monthly Mean Surface cfnsf.sfc.mon.mean.nc plot
Cloud forcing net solar flux Monthly Long Term Mean Surface cfnsf.sfc.mon.ltm.nc plot
Cloud forcing net solar flux Daily Long Term Mean Surface cfnsf.sfc.day.ltm.nc plot
Cloud forcing net solar flux 4X Daily Long Term Mean Surface cfnsf.sfc.4Xday.ltm.nc plot
Convective Precipitation rate Monthly Mean Surface cprat.sfc.mon.mean.nc plot
Convective Precipitation rate Long Term Monthly Mean Surface cprat.sfc.mon.ltm.nc plot
Convective Precipitation rate Daily Long Term Mean Surface cprat.sfc.day.ltm.nc plot
Convective Precipitation rate 4X Daily Long Term Mean Surface cprat.sfc.4Xday.ltm.nc plot
Clear sky downward longwave flux Monthly Mean Surface csdlf.sfc.mon.mean.nc plot
Clear sky downward longwave flux Monthly Long Term Mean Surface csdlf.sfc.mon.ltm.nc plot
Clear sky downward longwave flux Daily Long Term Mean Surface csdlf.sfc.day.ltm.nc plot
Clear sky downward longwave flux 4X Daily Long Term Mean Surface csdlf.sfc.4Xday.ltm.nc plot
Clear sky downward solar flux Monthly Mean Surface csdsf.sfc.mon.mean.nc plot
Clear sky downward solar flux Monthly Long Term Mean Surface csdsf.sfc.mon.ltm.nc plot
Clear sky downward solar flux Daily Long Term Mean Surface csdsf.sfc.day.ltm.nc plot
Clear sky downward solar flux 4 Daily Long Term Mean Surface csdsf.sfc.4Xday.ltm.nc plot
Downward longwave radiation flux Monthly Mean Surface dlwrf.sfc.mon.mean.nc plot
Downward longwave radiation flux Monthly Long Term Mean Surface dlwrf.sfc.mon.ltm.nc plot
Downward longwave radiation flux Daily Long Term Mean Surface dlwrf.sfc.day.ltm.nc plot
Downward longwave radiation flux 4X Daily Long Term Mean Surface dlwrf.sfc.4Xday.ltm.nc plot
Downward shortwave radiation flux Monthly Mean Surface dswrf.sfc.mon.mean.nc plot
Downward shortwave radiation flux Monthly Long Term Mean Surface dswrf.sfc.mon.ltm.nc plot
Downward shortwave radiation flux Daily Long Term Mean Surface dswrf.sfc.day.1981-2010.ltm.nc plot
Downward shortwave radiation flux 4X 4X Daily Long Term Mean Surface dswrf.sfc.4Xday.1981-2010.ltm.nc plot
Ground heat flux Monthly Mean Surface gflux.sfc.mon.mean.nc plot
Ground heat flux Monthly Long Term Mean Surface gflux.sfc.mon.ltm.nc plot
Ground heat flux Daily Long Term Mean Surface gflux.sfc.day.1981-2010.ltm.nc plot
Ground heat flux 4X Daily Long Term Mean Surface gflux.sfc.4Xday.1981-2010.ltm.nc plot
Latent heat net flux Monthly Mean Surface lhtfl.sfc.mon.mean.nc plot
Latent heat net flux Monthly Long Term Mean Surface lhtfl.sfc.mon.ltm.nc plot
Latent heat net flux Daily Long Term Mean Surface lhtfl.sfc.day.1981-2010.ltm.nc plot
Latent heat net flux 4X Daily Long Term Mean Surface lhtfl.sfc.4Xday.1981-2010.ltm.nc plot
Near IR beam downward solar flux Monthly Mean Surface nbdsf.sfc.mon.mean.nc plot
Near IR beam downward solar flux Monthly Long Term Mean Surface nbdsf.sfc.mon.ltm.nc plot
Near IR beam downward solar flux Daily Long Term Mean Surface nbdsf.sfc.day.1981-2010.ltm.nc plot
Near IR beam downward solar flux 4X Daily Long Term Mean Surface nbdsf.sfc.4Xday.1981-2010.ltm.nc plot
Near IR Beam Downward Solar Flux Monthly Mean Surface nbdsf.sfc.mon.mean.nc plot
Near IR Beam Downward Solar Flux Monthly Long Term Mean Surface nbdsf.sfc.mon.ltm.nc plot
Near IR Beam Downward Solar Flux Daily Long Term Mean Surface nbdsf.sfc.day.1981-2010.ltm.nc plot
Near IR Beam Downward Solar Flux 4X Daily Long Term Mean Surface nbdsf.sfc.4Xday.1981-2010.ltm.nc plot
Near IR Diffuse Downward Solar Flux Monthly Mean Surface nddsf.sfc.mon.mean.nc plot
Near IR Diffuse Downward Solar Flux Monthly Long Term Mean Surface nddsf.sfc.mon.ltm.nc plot
Near IR Diffuse Downward Solar Flux Daily Long Term Mean Surface nddsf.sfc.day.1981-2010.ltm.nc plot
Near IR Diffuse Downward Solar Flux 4X Daily Long Term Mean Surface nddsf.sfc.4Xday.1981-2010.ltm.nc plot
Net longwave radiation Monthly Mean Surface nlwrs.sfc.mon.mean.nc plot
Net longwave radiation Monthly Long Term Mean Surface nlwrs.sfc.mon.ltm.nc plot
Net longwave radiation Daily Long Term Mean Surface nlwrs.sfc.day.1981-2010.ltm.nc plot
Net shortwave radiation Monthly Mean Surface nswrs.sfc.mon.mean.nc plot
Net shortwave radiation Monthly Long Term Mean Surface nswrs.sfc.mon.ltm.nc plot
Net shortwave radiation Daily Long Term Mean Surface nswrs.sfc.day.1981-2010.ltm.nc plot
Precipitation rate Monthly Mean Surface prate.sfc.mon.mean.nc plot
Precipitation rate Monthly Long Term Mean Surface prate.sfc.mon.ltm.nc plot
Precipitation rate Daily Long Term Mean Surface prate.sfc.day.1981-2010.ltm.nc plot
Precipitation rate 4X Daily Long Term Mean Surface prate.sfc.4Xday.1981-2010.ltm.nc plot
Pressure Monthly Mean Surface pres.sfc.mon.mean.nc plot
Pressure Monthly Long Term Mean Surface pres.sfc.mon.ltm.nc plot
Pressure Daily Long Term Mean Surface pres.sfc.day.1981-2010.ltm.nc plot
Pressure 4X Daily Long Term Mean Surface pres.sfc.4Xday.1981-2010.ltm.nc plot
Sensible heat net flux Monthly Mean Surface shtfl.sfc.mon.mean.nc plot
Sensible heat net flux Monthly Long Term Mean Surface shtfl.sfc.mon.ltm.nc plot
Sensible heat net flux Daily Long Term Mean Surface shtfl.sfc.day.1981-2010.ltm.nc plot
Sensible heat net flux 4X Daily Long Term Mean Surface shtfl.sfc.4Xday.1981-2010.ltm.nc plot
Surface Roughness Monthly Mean Surface sfcr.sfc.mon.mean.nc plot
Surface Roughness Monthly Long Term Mean Surface sfcr.sfc.mon.ltm.nc plot
Surface Roughness Daily Long Term Mean Surface sfcr.sfc.day.1981-2010.ltm.nc plot
Surface Roughness 4X Daily Long Term Mean Surface sfcr.sfc.4Xday.1981-2010.ltm.nc plot
Upward Solar Radiation Flux Monthly Mean Surface uswrf.sfc.mon.mean.nc plot
Upward Solar Radiation Flux Monthly Long Term Mean Surface uswrf.sfc.mon.ltm.nc plot
Upward Solar Radiation Flux Daily Long Term Mean Surface uswrf.sfc.day.1981-2010.ltm.nc plot
Upward Solar Radiation Flux 4X Daily Long Term Mean Surface uswrf.sfc.4Xday.1981-2010.ltm.nc plot
Zonal component of momentum flux Monthly Mean Surface uflx.sfc.mon.mean.nc plot
Zonal component of momentum flux Monthly Long Term Mean Surface uflx.sfc.mon.ltm.nc plot
Zonal component of momentum flux Daily Long Term Mean Surface uflx.sfc.day.1981-2010.ltm.nc plot
Zonal component of momentum flux 4X Daily Long Term Mean Surface uflx.sfc.4Xday.1981-2010.ltm.nc plot
Zonal gravity wave stress Monthly Mean Surface ugwd.sfc.mon.mean.nc plot
Zonal gravity wave stress Monthly Long Term Mean Surface ugwd.sfc.mon.ltm.nc plot
Zonal gravity wave stress Daily Long Term Mean Surface ugwd.sfc.day.1981-2010.ltm.nc plot
Zonal gravity wave stress 4X Daily Long Term Mean Surface ugwd.sfc.4Xday.1981-2010.ltm.nc plot
Upward longwave radiation flux Monthly Mean Surface ulwrf.sfc.mon.mean.nc plot
Upward longwave radiation flux Monthly Long Term Mean Surface ulwrf.sfc.mon.ltm.nc plot
Upward longwave radiation flux Daily Long Term Mean Surface ulwrf.sfc.day.1981-2010.ltm.nc plot
Upward longwave radiation flux 4X Daily Long Term Mean Surface ulwrf.sfc.4Xday.1981-2010.ltm.nc plot
Visible Beam Downward Solar Flux Monthly Mean Surface vbdsf.sfc.mon.mean.nc plot
Visible Beam Downward Solar Flux Monthly Long Term Mean Surface vbdsf.sfc.mon.ltm.nc plot
Visible Beam Downward Solar Flux Daily Long Term Mean Surface vbdsf.sfc.day.1981-2010.ltm.nc plot
Visible Beam Downward Solar Flux 4X Daily Long Term Mean Surface vbdsf.sfc.4Xday.1981-2010.ltm.nc plot
Visible Diffuse Downward Solar Flux Monthly Mean Surface vddsf.sfc.mon.mean.nc plot
Visible Diffuse Downward Solar Flux Monthly Long Term Mean Surface vddsf.sfc.mon.ltm.nc plot
Visible Diffuse Downward Solar Flux Daily Long Term Mean Surface vddsf.sfc.day.1981-2010.ltm.nc plot
Visible Diffuse Downward Solar Flux 4X Daily Long Term Mean Surface vddsf.sfc.4Xday.1981-2010.ltm.nc plot
Meridional component of momemtum flux Monthly Mean Surface vflx.sfc.mon.mean.nc plot
Meridional component of momemtum flux Monthly Long Term Mean Surface vflx.sfc.mon.ltm.nc plot
Meridional component of momemtum flux Daily Long Term Mean Surface vflx.sfc.day.1981-2010.ltm.nc plot
Meridional component of momemtum flux 4X Daily Long Term Mean Surface vflx.sfc.4Xday.1981-2010.ltm.nc plot
Meridional gravity wave stress Monthly Mean Surface vgwd.sfc.mon.mean.nc plot
Meridional gravity wave stress Monthly Long Term Mean Surface vgwd.sfc.mon.ltm.nc plot
Meridional gravity wave stress Daily Long Term Mean Surface vgwd.sfc.day.1981-2010.ltm.nc plot
Meridional gravity wave stress 4X Daily Long Term Mean Surface vgwd.sfc.4Xday.1981-2010.ltm.nc plot
Water Equiv. of Accum. Snow Depth Monthly Mean Surface weasd.sfc.mon.mean.nc plot
Water Equiv. of Accum. Snow Depth Monthly Long Term Mean Surface weasd.sfc.mon.ltm.nc plot
Water Equiv. of Accum. Snow Depth Daily Long Term Mean Surface weasd.sfc.day.1981-2010.ltm.nc plot
Water Equiv. of Accum. Snow Depth 4X Daily Long Term Mean Surface weasd.sfc.4Xday.1981-2010.ltm.nc plot
Land-sea mask time invariant Surface lsmask.19294.nc plot

Usage Restrictions:

  • None

Detailed Description:

  • The NCEP/NCAR Reanalysis project is using a state-of-the-art analysis/forecast system to perform data assimilation using past data from 1948 to the present. A subset of this data has been processed to create monthly means of a subset of the original data. There are also files containing data from variables derived from the reanalysis and some other statistics. Information about the 4 times and daily data is available, as well.
  • A discussion of the sign convention for radiative fluxis is available.

Caveats:

  • Please read the problem list before using the data.
  • The netCDF data files for the NCEP/NCAR Reanalysis variable PEVPR (files named pevpr.sfc.gauss.YY.nc or pevpr.sfc.gauss.YYYY.nc) may have incorrect units for the pevpr (Potential Evaporation Rate) variable.

    The correct units are watts per meter squared (W/m^2).

    § The skt.sfc files contain skin temperature as described in the March, 1996 BAMS article. As such, over land and sea ice, the temperature is a prognostic variable. Over open water, the skin temperature is fixed at its initial value; i.e., the Reynolds SST as seen by the model. The Reynolds' SST analyses were done weekly and the reconstructed SST done monthly. The analyses were linearly interpolated to daily values which were used for all four analyses.

    The following variables are 6 hour forecast values valid 6 hours after the reference time: air, air.2m, icec, pres, runof, sfcr, shum.2m, soilw.0-10cm, soilw.10-200cm, tmax.2m, tmin.2m, tmp.0-10cm, tmp.10-200cm, tmp.300cm, uwnd.10m, vwnd.10m, weasd, land

    The following variables are six hour averages for the period of the reference time plus six hours: cfnlf, cfnsf, cprat, csdlf, csdsf, dlwrf, dswrf, gflux, lhtfl, nbdsf, nddsf, prate, shtfl, uflx, ugwd, ulwrf, uswrf, vbdsf, vddsf, vflx, vgwd, nlwrs, nswrs

Related File Naming & Structure Information:

File Names:

  • The naming convention of the files is generally
    variable.averagingperiod.statistic.nc
    where
    variable is netcdf variable name
    averagingperiod is time period over which data is averaged (day,mon)
    statistic is type of data (mean, long-term mean(ltm), etc)

    Some files have the level included with the variable names
    e.g. air2m.mon.mean.nc
    Here the file should be read with the variable of 'air'

    OpenDap File Names:

    • /thredds/dodsC/Datasets/ncep.reanalysis.derived/surface_flux/variable.averagingperiod.statistic.nc.

    Information is available on the time period of the files and how the different statistics were calculated.

    Jump to: Other General Information

  • All data are stored in netCDF files
  • The data are divided by variable and statistic
  • There are 60 files currently, ranging in size from 73 Kbytes to 44.7 Mbytes
  • The total disk space consumed by this category is currently 1.1 Gbytes
  • var.time.stat.nc   (In directory: /Datasets/ncep.reanalysis.derived/surface_flux/)

Dataset Format and Size:

  • PSL standard NetCDF 311 Mbyte file for each monthly file (packed).
  • PSL standard NetCDF 30 Mbyte file for each long term mean file (packed).

Missing Data:

  • Missing data is flagged with a value of -9.96921e+36f.

Citation:

  • For dataset source, please cite:Kalnay et al.,The NCEP/NCAR 40-year reanalysis project, Bull. Amer. Meteor. Soc., 77, 437-470, 1996.
  • Please note: If you acquire NCEP Reanalysis Derived data products from PSL, we ask that you acknowledge us in your use of the data. This may be done by including text such as NCEP Reanalysis Derived data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at / in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSL to justify keeping the NCEP Reanalysis Derived data set freely available online in the future. Thank you!

References:

  • March, 1996 BAMS

Original Source:

  • NOAA National Center for Environmental Prediction

Contact:

  • Physical Sciences Laboratory: Data Management
    NOAA/ESRL/PSL
    325 Broadway
    Boulder, CO 80305-3328
    psl.data@noaa.gov
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