NCEP North American Regional Reanalysis: NARR


See the PSD NARR webpage for more information on PSD's involvement in the NARR project

Brief Description:

  • NCEP's high resolution combined model and assimilated dataset. It covers 1979 to near present and is provided 8-times daily, daily and monthly on a Northern Hemisphere Lambert Conformal Conic grid for all variables. More...

Temporal Coverage:

  • 8-times, Daily and Monthly means for 1979/01/01 to Dec 31, 2013 .
  • Long Term Daily, Monthly means for years 1979 - 2000.

Spatial Coverage:

  • The native model grid is converted to a Northern Lambert Conformal Conic grid which is what we archive. Corners of this grid are 12.2N;133.5W, 54.5N; 152.9W, 57.3N; 49.4W ,14.3N;65.1W (essentially, North America). The grid resolution is 349x277 which is approximately 0.3 degrees (32km) resolution at the lowest latitude. A page describing the coverage along with information on reading the projection is available.

Levels:

  • 29 pressure levels (hPa):
    1000, 975, 950, 925, 900, 875, 850, 825, 800, 775, 750, 725, 700, 650, 600, 550, 500, 450, 400, 350, 300, 275, 250, 225, 200, 175, 150, 125, 100
  • soil variables: 0 , 10 , 40 , 100, (800) cm
  • monolevel
    Single level including surface and near surface, top of atmosphere and cloud heights, and entire atmosphere.

Update Schedule:

  • Static

The NCEP NARR descriptions here will be subdivided into separate sections: Pressure level, Monolevel (surface and others) and Subsurface

Also Available Plotting Pages:  

Usage Restrictions:

  • None

Detailed Description:

  • The NARR project is an extension of the NCEP Global Reanalysis which is run over the North American Region. The NARR model uses the very high resolution NCEP Eta Model (32km/45 layer) together with the Regional Data Assimilation System (RDAS) which, significantly, assimilates precipitation along with other variables. The improvements in the model/assimilation have resulted in a dataset with substantial improvements in the accuracy of temperature, winds and precipitation compared to the NCEP-DOE Global Reanalysis 2. We currently have output which includes 8 times daily data at 29 levels and most of the variables. For a complete list of model output variables, see NCEP's variable list.
  • Additional information can be found at NCEP's NARR page.

Caveats:

Related File Naming & Structure Information:

File Names:

  • 8-times daily and daily File names are composed of variable abbreviations and year/month or just year : as yyyymm.nc or yyyy.nc(In directory: /Datasets/NARR/ or /Datasets/NARR/Dailies/)
  • Monthly means/ltms are (variable).mon.mean.nc in /Datasets/NARR/Monthlies/

Dataset Format and Size:

  • All data are stored in PSD standard NetCDF files and are (packed).
  • The data are divided by variable and year and month into separate files
  • There are 2100 files currently
  • Size of file is about 1.4G per variable per year/month for 8xdaily data
  • Size of file is about 68M per variable per /month for monthly data
  • Current total of 29.4 Tbytes for 8xDaily.
  • 8x daily data are available from ftp.cdc.noaa.gov in /Datasets/NARR/.
  • The 8x data files are quite large, so you may only be able to download them if you have a fast network connection.

Missing Data:

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

Citation:

  • Please note: If you acquire NCEP Reanalysis 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 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 data set freely available online in the future. Thank you!
  • NORTH AMERICAN REGIONAL REANALYSIS: A long-term, consistent, high-resolution climate dataset for the North American domain, as a major improvement upon the earlier global reanalysis datasets in both resolution and accuracy, Fedor Mesinger et. al, submitted to BAMS 2004.

References:

  • NORTH AMERICAN REGIONAL REANALYSIS: A long-term, consistent, high-resolution climate dataset for the North American domain, as a major improvement upon the earlier global reanalysis datasets in both resolution and accuracy, Fedor Mesinger et. al, submitted to BAMS 2004.

Original Source:

  • Dataset was originally produced at NOAA's National Center for Atmospheric Prediction (NCEP) and is available in it's original grib format through NOAA NCDC's access page. It is also available in the same format from NCAR.

Contact:

  • Physical Sciences Division: Data Management
    NOAA/ESRL/PSD
    325 Broadway
    Boulder, CO 80305-3328
    esrl.psd.data@noaa.gov