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NOAA Daily (non-interpolated) Outgoing Longwave Radiation (OLR)

Brief Description:

  • Gridded OLR data from NCEP without interpolation. See the Interpolated OLR dataset for an interpolated version. More Details...

Temporal Coverage:

  • Daily values from 2002/01/01 to present (from twice daily Advanced Very High Resolution Radiometer (AVHRR) soundings for OLR).
  • Long term means for daily values for 1979-1995.

Spatial Coverage:

  • 2.5 degree latitude x 2.5 degree longitude global grid (144x73).
  • 90N - 90.0S, 0.0E - 357.5E.


  • N/A

Update Schedule:

  • Daily

Download/Plot Data: (FTP Access)

Variable Statistic Level Units Download File Create Plot/Subset
Outgoing Longwave Radiation Mean (Daily) Top of Atmosphere W/m^^2 olr.day.mean.nc plot image
Outgoing Longwave Radiation Long Term Mean (Daily) Top of Atmosphere W/m^^2 olr.daily.ltm.1979-1995.nc plot image

Usage Restrictions:

  • None but any feedback would be useful.

Detailed Description:


  • New satellite source.
  • As of 2005/08/07, this data set was switched from the NOAA-16 (last day 2005/08/07) satellite to the NOAA-18 satellite. The NOAA-18 bird crosses the equator at 0130 and 1330.
  • The sun-synchronous orbit means that at some locations and times 'night' will follow 'day', while at others 'day' will follow 'night', and there is a longitude at which the local time switches by nearly 24 hours. However, taking a daily mean of the day and night passes, as is done for this dataset, avoids the issue of which is observed first, and serves to reduce the effective time jump that occurs at the aforementioned longitude to 12 hours.

Related File Naming & Structure Information:

File Names:

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

OpenDap File Names:

  • /thredds/dodsC/Datasets/uninterp_OLR/var.time.stat.nc   

Dataset Format and Size:

  • PSL standard NetCDF 88 Mbyte file for each daily file (packed).
  • PSL standard NetCDF 7.7 Mbyte file for each daily long term mean file (packed).

Missing Data:

  • Missing data is flagged with a value of 32766s.
  • June 21, 2015 is missing (missing at source).


  • Please note: If you acquire Uninterpolated 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 Uninterpolated 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 Uninterpolated OLR data set freely available online in the future. Thank you!


  • None

Original Source:


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