NCEP/NCAR Reanalysis Monthly Means and Other Derived Variables
One-Line 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 1968 - 1996.
Spatial Coverage:
- 2.5 degree latitude x 2.5 degree longitude global grid (144x73).
- 90N - 90S, 0E - 357.5E
Levels:
-
Search keywords:
- Tropopause
Update Schedule:
- Monthly
| Variable | Statistic | Level | Download File | Create Plot/Subset |
|---|---|---|---|---|
| Air Temperature | Monthly Mean | Surface | air.mon.mean.nc | 
|
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:
- 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/surface.
- 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), "3_10"(3-10 day filtered std). (variable).(averaging period).(statistic).nc
OpenDap File Names:
- http://www.cdc.noaa.gov/cgi-bin/opendap/nph-nc/Datasets/ncep.reanalysis.derived/tropopause/var.time.stat.nc
Dataset Format and Size:
- PSD standard NetCDF xx (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.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 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