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: * Surface or near the surface (.995 sigma level) * The variables on sigma level 0.995 are: air, rhum, uwnd, vwnd and wspd. * Also, precipitable water is included here, because it is a 3-D file on a 2.5 degree grid, but it is not a surface value, but rather for the entire atmospheric column Update Schedule: * Monthly Download/Plot Data: Variable Statistic Level Download File Create Plot/Subset Air Temperature Monthly Mean Surface air.mon.mean.nc plot Air Temperature Monthly Long Term Mean Surface air.mon.ltm.nc plot Air Temperature Daily Long Term Mean Surface air.day.ltm.nc plot Precipitable water Monthly Mean Columnar Total pr_wtr.mon.mean.nc plot Precipitable water Monthly Long Term Mean Columnar Total pr_wtr.mon.ltm.nc plot Pressure Monthly Mean Surface pres.mon.mean.nc plot Pressure Monthly Long Term Mean Surface pres.mon.ltm.nc plot Pressure Daily Long Term Mean Surface pres.day.ltm.nc plot Relative humidity Monthly Mean Surface rhum.mon.mean.nc plot Relative humidity Monthly Long Term Mean Surface rhum.mon.ltm.nc plot Sea level pressure Monthly Mean Surface slp.mon.mean.nc plot Sea level pressure Monthly Long Term Mean Surface slp.mon.ltm.nc plot Sea level pressure Monthly Interannual STD Surface slp.mon.inter.std.nc plot Sea level pressure Daily Long Term Mean Surface slp.day.ltm.nc plot Zonal Wind Monthly Mean Surface uwnd.mon.mean.nc plot Zonal Wind Monthly Long Term Mean Surface uwnd.mon.ltm.nc plot Zonal Wind Daily Long Term Mean Surface uwnd.day.ltm.nc plot Meridional Wind Monthly Mean Surface vwnd.mon.mean.nc plot Meridional Wind Monthly Long Term Mean Surface vwnd.mon.ltm.nc plot Meridional Wind Daily Long Term Mean Surface vwnd.day.ltm.nc plot Land Sea Mask Time Invariant Surface lsmask.nc plot Wind Speed Monthly Mean Surface wspd.mon.mean.nc plot Wind Speed Monthly Long Term Mean Surface wspd.mon.ltm.nc plot Note: These variables are instantaneous values at the reference time. These variables are averages of instantaneous values at the 4 reference times; 0,6,12 and 18z over the averaging period (month, day) 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.esrl.noaa.gov/psd/thredds/dodsC/Datasets/ncep.reanalysi s.derived/surface/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.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 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 U.S. Department of Commerce | National Oceanic and Atmospheric Administration Earth System Research Laboratory | Physical Sciences Division http://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.derived .surface.html