NCEP/NCAR Reanalysis Monthly Means and Other Derived Variables
One-Line Description:
- NCEP/NCAR Reanalysis Monthly Means and Other Derived Variables..
- Pressure Level Data
- Surface Data
- Surface Flux Data
- Other Flux Data
- Tropopause Level Data
- Sigma Level Data
Temporal Coverage:
- Daily and Monthly Values for 1948/01 - present.
- Long term monthly means, derived from data for years 1968 - 1996.
Spatial Coverage:
-
Spatial coverage:
- T62 Gaussian grid with 192x94 points
- 88.542N-88.542S, 0E-358.125E
Levels:
- 2 Sigma levels: 0.995,0.2101 for monthly means
- 5 sigma levels 0.995 , 0.8458 , 0.2582 , 0.2101 , 0.1682 for daily chi,psi
Update Schedule:
- Monthly
Download/Plot Data:
Variable | Statistic | Level | Download File | Create Plot/Subset |
---|---|---|---|---|
Air temperature | air | degC | mon mean,ltm,daily ltm, | |
  |   |   | diurnal cycle (4 different months) | |
  |   |   | 1st 2 eofs NH, calculated | |
  |   |   | separately for each level | |
Geopotential height | hgt | m | mon mean,ltm,daily ltm | |
  |   |   | diurnal cycle (4 different months) | |
  |   |   | 1st 2 eofs NH, calculated | |
  |   |   | separately for each level | |
Relative humidity | rhum | % | mon mean,ltm | |
Specific humidity | shum | g/kg | mon mean,ltm,daily ltm | |
Omega (vertical velocity) | omega | Pascal/s | mon mean,ltm | |
U-wind | uwnd | m/s | mon mean,ltm,daily ltm, | |
  |   |   | 1st 2 eofs NH, calculated | |
  |   |   | separately for each level | |
V-wind | vwnd | m/s | mon mean,ltm | |
Land-sea mask (time invariant) * | lsmask | (0 or 1) | none | |
Derived variables include: | File | Units | Statistics Available | |
Usage Restrictions:
- None
Detailed Description:
- Cort Willmott & Kenji Matsuura of the University of Delaware have put data together from a large number of stations, both from the GHCN (Global Historical Climate Network) and, more extensively, from the archive of Legates & Willmott. The result is a monthly climatology of precipitation and air temperature, both at the surface, and a time series, spanning 1950 to 1999, of monthly mean surface air temperatures, and monthly total precipitation. It is land-only in coverage, and complements the ICOADS (International Comprehensive Ocean-Atmosphere Data Set) data set well. The version we have stored online is 1.02 and some values will have changed from our 1950-1996 files. For a complete description of the data as given by the providers and references to relevant papers please see their web pages at the University of Delaware.
Caveats:
- None
Related File Naming & Structure Information:
File Names:
- var.time.stat.nc (In directory: /Datasets/udel.airt.precip/)
Dataset Format and Size:
- CDC standard NetCDF 311 Mbyte file for each monthly file (packed).
- CDC standard NetCDF 30 Mbyte file for each long term mean file (packed).
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 UDel_AirT_Precip 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 UDel_AirT_Precip 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 UDel_AirT_Precip data set freely available online in the future. Thank you!
References:
- Legates, D. R. and C. J. Willmott (1990a) Mean Seasonal and Spatial Variability Global Surface Air Temperature. Theoretical and Applied Climatology , 41, 11-21.
- Shepard, D. (1968) A two-dimensional Interpolation function for irregularly-spaced Data. Proceedings, 1968 ACM National Conference, 517-523.
- Willmott, C. J., C. M. Rowe and W. D. Philpot (1985) Small-Scale Climate Maps: A Sensitivity Analysis of Some Common Assumptions Associated with Grid-point Interpolation and Contouring. American Cartographer, 12, 5-16.
- Willmott, C. J. and K. Matsuura (1995) Smart Interpolation of Annually Averaged Air Temperature in the United States. Journal of Applied Meteorology, 34, 2577-2586.
Original Source:
- Center for Climatic Research Department of Geography University of Delaware Newark, DE 19716 The University of Delaware Web site offers extensive documentation of this data set. Please address questions on the analysis method to Kenji Matsuura (kenjisan@udel.edu) University of Delaware.
Contact:
- Physical Sciences Division: Data Management
NOAA/ESRL/PSD
325 Broadway
Boulder, CO 80305-3328
esrl.psd.data@noaa.gov