View Article

view the latest news articles
Why NASA Keeps a Close Eye on the Sun's Irradiance by Adam Voiland
Wednesday, May 26th 2010, 9:45 AM EDT
Co2sceptic (Site Admin)
Image Attachment(PhysOrg.com) -- For more than two centuries, scientists have wondered how much heat and light the sun expels, and whether this energy varies enough to change Earth’s climate. In the absence of a good method for measuring the sun's output, the scientific conversation was often heavy with speculation.

By 1976, that began to change when Jack Eddy, a solar astronomer from Boulder, Colo., examined historical records of sunspots and published a seminal paper that showed some century-long variations in solar activity are connected with major climatic shifts. Eddy helped show that an extended lull in solar activity during the 17th Century --called the Maunder Minimum -- was likely connected to a decades-long cold period on Earth called the "Little Ice Age."

Two years after Eddy published his paper, NASA launched the first in a series of satellite instruments called radiometers, which measure the amount of sunlight striking the top of Earth's atmosphere, or total solar irradiance. Radiometers have provided unparalleled details about how the sun's irradiance has varied in the decades since. Such measurements have helped validate and expand upon Eddy's findings. And they've led to a number of other discoveries—and questions—about the sun.

Without radiometers, scientists would probably still wonder how much energy the sun emits and whether it varies with the sunspot cycle. They wouldn't know of the competition between dark sunspots and bright spots called faculae that drives irradiance variations.

And they’d have little chance of answering a question that continues to perplex solar experts today: Has overall irradiance changed progressively throughout the past three 11-year cycles, or are variations in the sun's irradiance limited to a single cycle?


Article continues below this advert:

The answer has important implications for understanding climate change, as some scientists have suggested that trends in solar irradiance account for a significant portion of global warming.

The next space radiometer, slated for launch this November aboard NASA's Glory satellite, should help chip away at the uncertainty that surrounding the sun's role in climate change.

Click source to read FULL report from Adam Voiland
Source Link: physorg.com
Articles by Climate Realists and Topics

» Recently used highlighted

ALL #-E F-J K-O P-T U-Z
Useful links
Disclaimer
  • » News articles may contain quotes, these are copyright to the respective publication which will be stated, along with a link to the source article where available.
  • » If you feel your copyright has been violated please contact us and the article will be removed or amended at your request.
Site Details
  • » Launched 15 May 2009
  • » Website Design by Mr Zippy
Climate Depot Feed
  • » Feed Error