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NOAA's Outgoing Longwave Radiation–Daily Climate Data Record (OLR–Daily CDR)

Brief Description:

  • Gridded daily 1x1 OLR CDR data from NCDC interpolated to -90 to 90. More Details...

Temporal Coverage:

  • Daily values for 1979/01/01 - 12/31/2012.
  • Monthly values for 1979/01/01 - 12/01/2012.
  • Long Term means for daily,monthly values for 1981-2010.

Spatial Coverage:

  • 1.0 degree latitude x 1.0 degree longitude global grid (360x181)
  • 90.0N - 90.0S 0.5E - 359.5E


  • N/A

Update Schedule:

  • Static.

Download/Plot Data: (FTP Access)

Variable Statistic Level Units Download File Create Plot/Subset
OLR Daily Mean Top of Atmosphere W/m^2 olr.day.mean.nc plot
' ' Daily Long Term Mean Top of Atmosphere W/m^2 olr.day.ltm.nc plot
OLR Monthly Mean Top of Atmosphere W/m^2 olr.mon.mean.nc plot
' ' Monthly Long Term Mean Top of Atmosphere W/m^2 olr.mon.ltm.nc plot

Analysis/Plotting Tools:

Usage Restrictions:

Detailed Description:

  • PSL has generated a single netCDF file containing the NCDC CDR OLR dataset of daily values. The data has been interpolated so that it is symmetric about the equator (latitudinal grid resolution is 181 from the original 180; longitude resolution has not been changed). The original NCDC product contains the 1-degree by 1-degree daily mean outgoing longwave radiation flux at the top of the atmosphere derived from HIRS radiance observations onboard NOAA TIROS-N series and MetOp satellites. The OLR retrieval uses multispectral regression models (Ellingson et al., 1989, Lee, 2014). The CDR processing includes HIRS radiance calibration, inter-satellite HIRS OLR calibration, normalization of geostationary-based OLR retrieval to HIRS, and grid-based 7-day boxcar temporal integration assisted with Imager-based OLR derived from Gridsat CDR data (Lee, 2014).


  • None

Related File Naming & Structure Information:

File Names:

  • var.time.stat.nc   (In directory: /Datasets/olrcdr/)

OpenDap File Names:

  • /thredds/dodsC/Datasets/olrcdr/olr.time.stat.nc   

Dataset Format and Size:

  • PSL standard NetCDF4 2.1G file for daily file.
  • PSL standard NetCDF3 95M file for daily ltm file.
  • PSL standard NetCDF3 106M file for monthly file.
  • PSL standard NetCDF3 4.6M file for monthly ltm file.

Missing Data:

  • Missing data is flagged with a value of -9.96921e+36.


  • NCDC use agreement
  • Lee, H.-T., 2014: Climate Algorithm Theoretical Basis Document (C-ATBD): Outgoing Longwave Radiation (OLR) - Daily. NOAA’s Climate Data Record (CDR) Program, CDRP-ATBD-0526, 46 pp. http://www1.ncdc.noaa.gov/pub/data/sds/cdr/CDRs/Outgoing%20Longwave%20Radiation%20-%20Daily/AlgorithmDescription.pdf.
  • Please note: If you acquire Interpolated OLR data products from PSL, we ask that you acknowledge us in your use of the data. This may be done by including text such as Interpolated OLR data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at / in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSL to justify keeping the Interpolated OLR data set freely available online in the future. Thank you!


Original Source:


  • Physical Sciences Laboratory: Data Management
    325 Broadway
    Boulder, CO 80305-3328