2013-01-08. Solar Variability and Terrestrial Climate |

posted Feb 7, 2013, 11:51 AM by Alan Gould
NASA Science News. Relevant to GSS Energy Flow chapter 4, Ozone chapter8, and Climate Change chapter 7. Excerpt: ...In the galactic scheme of things, the Sun is a remarkably constant star.  While some stars exhibit dramatic pulsations, wildly yo-yoing in size and brightness, and sometimes even exploding, the luminosity of our own sun varies a measly 0.1% over the course of the 11-year solar cycle.  There is, however, a dawning realization among researchers that even these apparently tiny variations can have a significant effect on terrestrial climate. A new report issued by the National Research Council (NRC), "The Effects of Solar Variability on Earth's Climate" [at http://www.nap.edu/catalog.php?record_id=13519] lays out some of the surprisingly complex ways that solar activity can make itself felt on our planet. ...Greg Kopp of the Laboratory for Atmospheric and Space Physics at the University of Colorado, pointed out that ... "Even typical short term variations of 0.1% in incident irradiance exceed all other energy sources (such as natural radioactivity in Earth's core) combined," he says. Of particular importance is the sun's extreme ultraviolet (EUV) radiation, which ...varies not by a minuscule 0.1%, but by whopping factors of 10 or more.  This can strongly affect the chemistry and thermal structure of the upper atmosphere.  ...In recent years, researchers have considered the possibility that the sun plays a role in global warming. After all, the sun is the main source of heat for our planet. The NRC report suggests, however, that the influence of solar variability is more regional than global…. Read the full article: http://science.nasa.gov/science-news/science-at-nasa/2013/08jan_sunclimate/