1. On the Relation Between Solar Activity and Clear-Sky Terrestrial Irradiance
- Author
-
Georg Feulner
- Subjects
media_common.quotation_subject ,Irradiance ,FOS: Physical sciences ,Solar irradiance ,Atmospheric sciences ,Atmosphere ,Observatory ,Astrophysics::Solar and Stellar Astrophysics ,Physics::Atmospheric and Oceanic Physics ,media_common ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,geography ,Sunspot ,geography.geographical_feature_category ,integumentary system ,food and beverages ,Astronomy and Astrophysics ,Solar cycle ,Physics - Atmospheric and Oceanic Physics ,Volcano ,Space and Planetary Science ,Sky ,Atmospheric and Oceanic Physics (physics.ao-ph) ,biological sciences ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The Mauna Loa Observatory record of direct-beam solar irradiance measurements for the years 1958-2010 is analysed to investigate the variation of clear-sky terrestrial insolation with solar activity over more than four solar cycles. The raw irradiance data exhibit a marked seasonal cycle, extended periods of lower irradiance due to emissions of volcanic aerosols, and a long-term decrease in atmospheric transmission independent of solar activity. After correcting for these effects, it is found that clear-sky terrestrial irradiance typically varies by about 0.2 +/- 0.1% over the course of the solar cycle, a change of the same order of magnitude as the variations of the total solar irradiance above the atmosphere. An investigation of changes in the clear-sky atmospheric transmission fails to find a significant trend with sunspot number. Hence there is no evidence for a yet unknown effect amplifying variations of clear-sky irradiance with solar activity., 16 pages, 7 figures, in press at Solar Physics; minor changes to the text to match final published version
- Published
- 2012