National Climatic Data Center
U.S. Department of Commerce

Outgoing Longwave Radiation (OLR)

National Oceanic and Atmospheric Administration

National Climatic Data Center

Outgoing Longwave Radiation (OLR) data at the top of the atmosphere are observed from the Advanced Very High Resolution Radiometer (AVHRR) instrument aboard the NOAA polar orbiting spacecraft. Data are centered across equatorial areas from 160°E to 160°W longitude. The raw data are converted into a standardized anomaly index. Negative (Positive) OLR are indicative of enhanced (suppressed) convection and hence more (less) cloud coverage typical of El Niño (La Niña) episodes. More (Less) convective activity in the central and eastern equatorial Pacific implies higher (lower), colder (warmer) cloud tops, which emit much less (more) infrared radiation into space. More information can be found at the Climate Prediction Center OLR page.

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Outgoing Longwave Radiation (OLR) Last 12 Months (W/m2)
Jun 2012Jul 2012Aug 2012Sep 2012Oct 2012Nov 2012Dec 2012Jan 2013Feb 2013Mar 2013Apr 2013May 2013
+0.2
+0.2
+0.7
+0.1
+0.6
+0.6
-0.7
-0.4
-0.2
-0.2
-0.3
Source: http://www.cpc.ncep.noaa.gov/data/indices/olr
Outgoing Longwave Radiation (OLR) Period of Record Time series
Outgoing Longwave Radiation (OLR)
Period of Record Time series
Outgoing Longwave Radiation (OLR) Time series since 2000
Outgoing Longwave Radiation (OLR)
Time series since 2000

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