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NCEP/NCAR Reanalysis Monthly Means and Other Derived Variables

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:

  • Nominal top of atmosphere (NTAT).

Update Schedule:

  • Monthly

Download/Plot Data:

Variable Statistic Level Download File Create Plot/Subset File Metadata
Clear Sky Upward Longwave Flux Monthly Means Nominal Top of atmosphere csulf.ntat.mon.mean.nc plot File Metadata
Clear Sky Upward Longwave Flux Monthly Long Term Means Nominal Top of atmosphere csulf.ntat.mon.ltm.nc plot File Metadata
Clear Sky Upward Longwave Flux Daily Long Term Means Nominal Top of atmosphere csulf.ntat.day.1981-2010.ltm.nc plot File Metadata
Clear Sky Upward Longwave Flux 4X Daily Long Term Means Nominal Top of atmosphere csulf.ntat.4Xday.1981-2010.ltm.nc plot File Metadata
Clear Sky Upward Shortwave Flux Monthly Means Nominal Top of atmosphere csusf.ntat.mon.mean.nc plot File Metadata
Clear Sky Upward Shortwave Flux Monthly Long Term Means Nominal Top of atmosphere csusf.ntat.mon.ltm.nc plot File Metadata
Clear Sky Upward Shortwave Flux Daily Long Term Means Nominal Top of atmosphere csusf.ntat.day.1981-2010.ltm.nc plot File Metadata
Clear Sky Upward Shortwave Flux 4X Daily Long Term Means Nominal Top of atmosphere csusf.ntat.4Xday.1981-2010.ltm.nc plot File Metadata
Downward Solar Radiation Flux Monthly Means Nominal Top of atmosphere dswrf.ntat.mon.mean.nc plot File Metadata
Downward Solar Radiation Flux Monthly Long Term Means Nominal Top of atmosphere dswrf.ntat.mon.ltm.nc plot File Metadata
Downward Solar Radiation Flux Daily Long Term Means Nominal Top of atmosphere dswrf.ntat.day.1981-2010.ltm.nc plot File Metadata
Downward Solar Radiation Flux 4X Daily Long Term Means Nominal Top of atmosphere dswrf.ntat.4Xday.1981-2010.ltm.nc plot File Metadata
Pressure Monthly Means High cloud bottom pres.hcb.mon.mean.nc plot File Metadata
Pressure Monthly Long Term Means High cloud bottom pres.hcb.mon.ltm.nc plot File Metadata
Pressure Daily Long Term Means High cloud bottom pres.hcb.day.1981-2010.ltm.nc plot File Metadata
Pressure 4X Daily Long Term Means High cloud bottom pres.hcb.4Xday.1981-2010.ltm.nc plot File Metadata
Pressure Monthly Means High cloud top pres.hct.mon.mean.nc plot File Metadata
Pressure Monthly Long Term Means High cloud top pres.hct.mon.ltm.nc plot File Metadata
Pressure Daily Long Term Means High cloud top pres.hct.day.1981-2010.ltm.nc plot File Metadata
Pressure 4X Daily Long Term Means High cloud top pres.hct.4Xday.1981-2010.ltm.nc plot File Metadata
Pressure Monthly Means Low cloud bottom pres.lcb.mon.mean.nc plot File Metadata
Pressure Monthly Long Term Means Low cloud bottom pres.lcb.mon.ltm.nc plot File Metadata
Pressure Daily Long Term Means Low cloud bottom pres.lcb.day.1981-2010.ltm.nc plot File Metadata
Pressure 4X Daily Long Term Means Low cloud bottom pres.lcb.4Xday.1981-2010.ltm.nc plot File Metadata
Pressure Monthly Means Low cloud top pres.lct.mon.mean.nc plot File Metadata
Pressure Monthly Long Term Means Low cloud top pres.lct.mon.ltm.nc plot File Metadata
Pressure Daily Long Term Means Low cloud top pres.lct.day.1981-2010.ltm.nc plot File Metadata
Pressure 4X Daily Long Term Means Low cloud top pres.lct.4Xday.1981-2010.ltm.nc plot File Metadata
Pressure Monthly Means Middle cloud bottom pres.mcb.mon.mean.nc plot File Metadata
Pressure Monthly Long Term Means Middle cloud bottom pres.mcb.mon.ltm.nc plot File Metadata
Pressure Daily Long Term Means Middle cloud bottom pres.mcb.day.1981-2010.ltm.nc plot File Metadata
Pressure 4X Daily Long Term Means Middle cloud bottom pres.mcb.4Xday.1981-2010.ltm.nc plot File Metadata
Pressure Monthly Means Middle cloud top pres.mct.mon.mean.nc plot File Metadata
Pressure Monthly Long Term Means Middle cloud top pres.mct.mon.ltm.nc plot File Metadata
Pressure Daily Long Term Means Middle cloud top pres.mct.day.1981-2010.ltm.nc plot File Metadata
Pressure 4X Daily Long Term Means Middle cloud top pres.mct.4Xday.1981-2010.ltm.nc plot File Metadata
Total cloud cover Monthly Means Entire Atmosphere Considered As a Single Layer tcdc.eatm.mon.mean.nc plot File Metadata
Total cloud cover Monthly Long Term Means Entire Atmosphere Considered As a Single Layer tcdc.eatm.mon.ltm.nc plot File Metadata
Total cloud cover Daily Long Term Means Entire Atmosphere Considered As a Single Layer tcdc.eatm.day.1981-2010.ltm.nc plot File Metadata
Total cloud cover 4X Daily Long Term Means Entire Atmosphere Considered As a Single Layer tcdc.eatm.4Xday.1981-2010.ltm.nc plot File Metadata
Upward Longwave Radiation Flux Monthly Means Nominal Top of atmosphere ulwrf.ntat.mon.mean.nc plot File Metadata
Upward Longwave Radiation Flux Monthly Long Term Means Nominal Top of atmosphere ulwrf.ntat.mon.ltm.nc plot File Metadata
Upward Longwave Radiation Flux Daily Long Term Means Nominal Top of atmosphere ulwrf.ntat.day.1981-2010.ltm.nc plot File Metadata
Upward Longwave Radiation Flux 4X Daily Long Term Means Nominal Top of atmosphere ulwrf.ntat.4Xday.1981-2010.ltm.nc plot File Metadata
Upward Solar Radiation Flux Monthly Means Nominal Top of atmosphere uswrf.ntat.mon.mean.nc plot File Metadata
Upward Solar Radiation Flux Monthly Long Term Means Nominal Top of atmosphere uswrf.ntat.mon.ltm.nc plot File Metadata
Upward Solar Radiation Flux Daily Long Term Means Nominal Top of atmosphere uswrf.ntat.day.1981-2010.ltm.nc plot File Metadata
Upward Solar Radiation Flux 4X Daily Long Term Means Nominal Top of atmosphere uswrf.ntat.4Xday.1981-2010.ltm.nc plot File Metadata

Notes:

These variables are averages of instantaneous values at the 4 reference times; 0,6,12 and 18z over the averaging period (month, day)

Usage Restrictions:

  • None

Detailed Description:

  • The NCEP/NCAR Reanalysis 1 project is using a state-of-the-art analysis/forecast system to perform data assimilation using past data from 1948 to the present. A large subset of this data is available from PSD in its original 4 times daily format and as daily averages. However, the data from 1948-1957 is a little different, in the regular (non-Gaussian) gridded data. That data was done at 8 times daily in the model, because the inputs available in that era were available at 3Z, 9Z, 15Z, and 21Z, whereas the 4x daily data has been available at 0Z, 6Z, 12Z, and 18Z. These latter times were forecasted and the combined result for this early era is 8x daily. The local ingestion process took only the 0Z, 6Z, 12Z, and 18Z forecasted values, and thus only those were used to make the daily time series and monthly means here.

Caveats:

  • None

Related File Naming & Structure Information:

File Names:

  • 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), and "inter.std" (interannual standard deviation). (variable).(averaging period).(statistic).nc e.g. csulftop.mon.mean.nc
  • All data are stored in netCDF files
  • The data are divided by variable and year into separate files
  • There are 18 files currently
  • Files range in size from 849 Kbytes to 44.7 Mbytes
  • Current total of 250 Mbytes.
  • var.time.stat.nc   (In directory: /Datasets/ncep.reanalysis.derived/)
  • Files are available by anonymous FTP from ftp.cdc.noaa.gov in /Datasets/ncep.reanalysis.derived/other_flux/.
  • 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

OpenDap File Names:

  • http://www.esrl.noaa.gov/psd/thredds/dodsC/Datasets/ncep.reanalysis.derived/other_gauss/var.time.stat.nc   

Dataset Format and Size:

  • PSD standard NetCDF (packed).
  • All data are stored in netCDF files
  • The data are divided by variable and year into separate files
  • There are 48 files currently
  • Files range in size from 167 Kbytes to 26 Mbytes
  • Current total of 377 Mbytes

Missing Data:

  • Missing data is flagged with a value of 32767s.

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 PSD, 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 PSD, Boulder, Colorado, USA, from their Web site at http://www.esrl.noaa.gov/psd/ in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSD 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 Division: Data Management
    NOAA/ESRL/PSD
    325 Broadway
    Boulder, CO 80305-3328
    esrl.psd.data@noaa.gov