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HOME > Monitoring and Data > Oceanic & Atmospheric Data > Global Precipitation Monitoring > Outgoing Longwave Radiation (OLR)

Outgoing Longwave Radiation (OLR) data at the top of the atmosphere are observed from the AVHRR instrument aboard the NOAA polar orbiting spacecraft. The units are watts/meter2.

These data are available as twice daily observation NOAA-16 and NOAA-17, pentad means and monthly means. Daily OLR data from January 1979 to present are available at the Climate Diagnostic Center ftp site.

The data are on a 2.5 x 2.5 degree lat/lon grid and are stored in 144 X 73 arrays that are oriented North Pole -> South Pole and eastward from Greenwich; note that all 144 values for j=1 and j=73 are for the north & south poles, respectively.

Pentad anomalies are computed with respect to the 1979 - 1995 base period.


Chelliah, M. and P. Arkin, 1992: Large-Scale Interannual Variability of Monthly Outgoing Longware Radiation Anomalies over the Global Tropics. J. Climate, 5, 371-389.

Gruber A. and A. F. Krueger, 1984: The Status of hte NOAA Outgoing Longwave Radiation Data Set. Bull. Amer. Meteor. Soc., 65, 958-962

Janowiak J. E., A.F.Krueger, P.A. Arkin and A. Gruber, 1985: Atlas of Outgoing Longwave Radiation Derived from NOAA Satellite Data NOAA Atlas No. 6 ( Available from Climate Prediction Center ), 44pp.

Liebmann B. and C.A.Smith, 1996: Description of a Complete ( Interpolated ) Outgoing Longwave Radiation Dataset. Bull. Amer. Meteor. Soc., 77, 1275-1277.

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