NCEP/NCAR Reanalysis 1: Surface Flux
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One-Line Description:
- NCEP/NCAR Reanalysis 1: Surface Flux data
Temporal Coverage:
- 4-times daily, daily and monthly values for 1948/01/01 to present
- Long term monthly means, derived from data for years 1968 - 1996
Spatial Coverage:
- T62 Gaussian grid with 192x94 points
- 88.542N-88.542S, 0E-358.125E
Levels:
- Surface or near the surface
Update Schedule:
- Daily
Variable | Statistic | Level | Download File | Create Plot/Subset |
---|---|---|---|---|
Geopotential Height | * | Surface | hgt.sfc.gauss.n |
* = no year in file name
These variables (air.2m - weasd) are forecasts valid 6 hours after the reference time:
Variable | Statistic | Level | Download File | Create Plot/Subset |
---|---|---|---|---|
Air Temperature 2m | 4-times Daily | 2m | see list | |
Air Temperature 2m | Daily | 2m | see list | |
Ice concentration | 4-times Daily | Surface | see list | |
Ice concentration | Daily | Surface | see list | |
Potential evaporation rate | 4-times Daily | Surface | see list | |
Potential evaporation rate | Daily | Surface | see list | |
Pressure | 4-times Daily | Surface | see list | |
Pressure | Daily | Surface | see list | |
Water Runoff | 4-times Daily | Surface | see list | |
Water Runoff | Daily | Surface | see list | |
Surface Roughness | 4-times Daily | Surface | see list | |
Surface Roughness | Daily | Surface | see list | |
Specific humidity at 2 meter | 4-times Daily | Surface | see list | |
Specific humidity at 2 meter | Daily | 2m | see list | |
Soil moisture (0-10cm) | 4-times Daily | 0-10cm | see list | |
Soil moisture (0-10cm) | Daily | Surface | see list | |
Soil moisture (10-200cm) | 4-times Daily | 10-200cm | see list | |
Soil moisture (10-200cm) | Daily | Surface | see list | |
Skin Temperature | 4-times Daily | Surface | see list | |
Skin Temperature | Daily | Surface | see list | |
Temperature of 0-10cm layer | 4-times Daily | Surface | see list | |
Temperature of 0-10cm layer | Daily | Surface | see list | |
Temperature of 10-200cm layer | 4-times Daily | Surface | see list | |
Temperature of 10-200cm layer | Daily | Surface | see list | |
Temperature at 300cm | 4-times Daily | Surface | see list | |
Temperature at 300cm | Daily | Surface | see list | |
U-wind at 10 m | 4-times Daily | Surface | see list | |
U-wind at 10 m | Daily | Surface | see list | |
V-wind at 10 m | 4-times Daily | Surface | see list | |
V-wind at 10 m | Daily | Surface | see list | |
Water equiv. of snow depth | 4-times Daily | Surface | see list | |
Water equiv. of snow depth | Daily | Surface | see list |
 
These variables are six-hour hindcasts from the reference time in the file:
Variable | Statistic | Level | Download File | Create Plot/Subset |
---|---|---|---|---|
Maximum temperature at 2m | 4-times Daily | Surface | see list | |
Maximum temperature at 2m | Daily | Surface | see list | |
Minimum temperature at 2m | 4-times Daily | Surface | see list | |
Minimum temperature at 2m | Daily | Surface | see list |
 
These variables (cfnlf.sfc - vgwd) are 6 hour averages starting at the reference time:
Variable | Statistic | Level | Download File | Create Plot/Subset |
---|---|---|---|---|
Cloud forcing net longwave flux | 4-times Daily | Surface | see list | |
Cloud forcing net longwave flux | Daily | Surface | see list | |
Cloud forcing net solar flux | 4-times Daily | Surface | see list | |
Cloud forcing net solar flux | Daily | Surface | see list | |
Convective precipitation rate | 4-times Daily | Surface | see list | |
Convective precipitation rate | Daily | Surface | see list | |
Clear sky downward longwave flux | <4-times Daily | Surface | see list | |
Clear sky downward longwave flux | Surface | see list | ||
Clear sky downward solar flux | 4-times Daily | Surface | see list | |
Clear sky downward solar flux | Daily | Surface | see list | |
Downward longwave radiation flux | 4-times Daily | Surface | see list | |
Downward longwave radiation flux | Daily | Surface | see list | |
Downward solar radiation flux | 4-times Daily | Surface | see list | |
Downward solar radiation flux | Daily | Surface | see list | |
Ground heat flux | 4-times Daily | Surface | see list | |
Ground heat flux | Daily | Surface | see list | |
Latent heat net flux | 4-times Daily | Surface | see list | |
Latent heat net flux | Daily | Surface | see list | |
Near IR beam downward solar flux | 4-times Daily | Surface | see list | |
Near IR beam downward solar flux | Daily | Surface | see list | |
Near IR diffuse downward solar flux | 4-times Daily | Surface | see list | |
Near IR diffuse downward solar flux | Daily | Surface | see list | |
Net longwave radiation | 4-times Daily | Surface | see list | |
Net longwave radiation | Daily | Surface | see list | |
Net shortwave radiation | 4-times Daily | Surface | see list | |
Net shortwave radiation | Daily | Surface | see list | |
Precipitation rate | 4-times Daily | Surface | see list | |
Precipitation rate | Daily | Surface | see list | |
Sensible heat net flux | 4-times Daily | Surface | see list | |
Sensible heat net flux | Daily | Surface | see list | |
Momentum flux (zonal) | 4-times Daily | Surface | see list | |
Momentum flux (zonal) | Daily | Surface | see list | |
Zonal gravity wave stress | 4-times Daily | Surface | see list | |
Zonal gravity wave stress | Daily | Surface | see list | |
Upward longwave radiation flux | 4-times Daily | Surface | see list | |
Upward longwave radiation flux | Daily | Surface | see list | |
Upward solar radiation flux | 4-times Daily | Surface | see list | |
Upward solar radiation flux | Daily | Surface | see list | |
Visible beam downward solar flux | 4-times Daily | Surface | see list | |
Visible beam downward solar flux | Daily | Surface | see list | |
Visible diffuse downward solar flu | 4-times Daily | Surface | see list | |
Visible diffuse downward solar flu | Daily | Surface | see list | |
Momentum flux (meridional) | 4-times Daily | Surface | see list | |
Momentum flux (meridional) | Daily | Surface | see list | |
Meridional gravity wave stress | 4-times Daily | Surface | see list | |
Meridional gravity wave stress | Daily | Surface | see list | |
Land-sea mask | 4-times Daily | Surface | see list |
* = no year in file name
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:
- 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 Evaportion 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.
Related File Naming & Structure Information:
File Names:
- Archive parameters: File names are composed of variable abbreviations, level, and year: (variable).(level).gauss.(year).nc
- See individual sections. Data in /Datasets/ncep.reanalysis/, Datasets/ncep.reanalysis.dailyavgs/, /Datasets/ncep.reanalysis.derived/
Dataset Format and Size:
- PSD standard NetCDF most are (packed).
- There are 1,720 files currently
- Files are 52 Mbytes per variable per year
- Current total of 90.4 Gbytes for 4xDaily and 22.6 Gbytes for daily averages
- The data are divided by variable and year into separate files
- 4x daily data are available from ftp.cdc.noaa.gov in /Datasets/ncep.reanalysis/surface_gauss/.
- The 4x data files are quite large, so you may only be able to download them if you have a fast network connection.
- Daily averages are available from ftp.cdc.noaa.gov in /Datasets/ncep.reanalysis.dailyavgs/surface_gauss/.
- If you would like datasets on a media such as tape, you will need to get them from another institution. NCAR (link) provides such a service for their datasets.
Missing Data:
- Missing data is flagged with a value of 32767s or 9.36e36f..
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 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!
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