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        Summary 
        Español: Variaciones en el ciclo solar.
        This picture depicts the last three  solar cycles as measured in  solar irradiance,  sunspot numbers,  solar flare activity, and 10.7 cm  radio flux. Solar irradiance, i.e the direct solar power at the top of the  Earth's atmosphere, is depicted as both a daily measurement and a moving annual average. All other data are depicted as the annual average value.
        See  w:solar variation for more information.
        Copyright 
        This image was created by  Robert A. Rohde from the published data listed below and replaces an image created by  William M. Connolley. It is part of the Global Warming Art project.
        
         
          Image from Global Warming Art
          This image is an original work created for  Global Warming Art. Please refer to the  image description page for more information.
          
         
          
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           Permission is granted to copy, distribute and/or modify this document under the terms of the  GNU Free Documentation License, Version 1.2 or any later version published by the  Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled  GNU Free Documentation License.  http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue 
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        Data sources 
        
         - Irradiance:  http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant
 
         - International sunspot number:  http://www.ngdc.noaa.gov/stp/SOLAR/ftpsunspotnumber.html
 
         - Flare index:  http://www.koeri.boun.edu.tr/astronomy/readme.html
 
         - 10.7cm radio flux:  http://www.drao-ofr.hia-iha.nrc-cnrc.gc.ca/icarus/www/sol_home.shtml
 
        
        References 
        
        
        
       File usage
       
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