NCEP North American Regional Reanalysis: NARR
One-Line Description:
- University of Delaware Global Air Temperature and Precipitation: monthly & climatologies.
Temporal Coverage:
- 8-times, Daily and Monthly means for 1979/01/01 to 2004/12/31.
- 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.
Update Schedule:
- As NCEP produces data in realtime, we will update our files.
The NCEP NARR descriptions here will be subdivided into separate sections. These are currently:
Download/Plot Data: Pressure Level Data
| Variable | Statistic | Level | Download File | Create Plot/Subset |
|---|---|---|---|---|
| Geopotential Height | Mean | 1000-100mb | hgt.197901.nc |  |
| Geopotential Height | Monthly Mean | '' | hgt.mon.mean.nc | |
| Zonal Wind | Mean | '' | uwnd.197901.nc | |
| Zonal Wind | Monthly Mean | '' | uwnd.mon.mean.nc | |
| Meridional Wind | Mean | '' | vwnd.197901.nc | |
| Meridional Wind | Monthly Mean | '' | vwnd.mon.mean.nc | |
| Omega | Mean | '' | omega.197901.nc | |
| Omega | Monthly Mean | '' | omega.mon.mean.nc | |
| Air Temperature | Mean | '' | air.197901.nc | |
| Air Temperature | Monthly Mean | '' | air.mon.mean.nc | |
| Specific Humidity | Mean | '' | shum.197901.nc | |
| Specific Humidity | Monthly Mean | '' | shum.mon.mean.nc | |
| Turbulent Kinetic Energy | Mean | '' | tke.197901.nc | |
| Turbulent Kinetic Energy | Monthly Mean | '' | tke.mon.mean.nc | |
Usage Restrictions:
- None
Detailed Description:
- Available Plotting Pages:
- These variables are instantaneous values at the reference time
- We plan on making all the data from 1979-2004 for our variable subset available for 8-times daily data, daily and and for monthly means.
-
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. The model currently has output from Jan 1, 1979-Dec 31 2004 which includes 8 times daily data at 29 levels.
Currently, CDC makes available the pressure level data only (Jan 1979-Dec 2004) though we plan to
later make available most of the surface and upper atmospheric variables for the complete time period.
For a complete list of model output variables, see NCEP's variable list.
Additional information can be found at NCEP's NARR page.
.
Caveats:
- Useful information can be found at NCEP's NARR FAQ page and from Albany's Department of Atmospheric Science NARR Usage Notes.
Related File Naming & Structure Information:
File Names:
- File names are composed of variable abbreviations and year/month: (variable).(year)(mm).nc(In directory: /Datasets/NARR/)
Dataset Format and Size:
- All data are stored in CDC 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.
- CDC standard NetCDF 311 Mbyte file for each monthly file (packed).
- CDC standard NetCDF 30 Mbyte file for each long term mean file (packed).
- 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.cdc.noaa.gov/ 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