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New Instrument Continues Gathering Sun’s Effects on the Earth
Dec. 5, 2013

Total solar irradiance

Total solar irradiance (shown in color) over the past three solar cycles since 1978 adjusted to a ground-based cryogenic instrument funded by NASA in collaboration with the National Institute of Standards and Technology (NIST).
Image Credit: Greg Kopp, LASP, University of Colorado / NASA

Maintaining a record of solar measurements is important in understanding the sun’s effect on Earth and the National Oceanic and Atmospheric Administration’s (NOAA), Total solar irradiance Calibration Transfer Experiment, or TCTE, is now providing that information.

Many natural conditions on Earth such as the surface temperature or air temperature depend on energy that comes from the sun in the form of electromagnetic radiation. A solar cycle lasts about 11 years and typically has modest changes in solar radiation. There are also dramatic solar events that eject solar material, but the energy variation caused by these particle emissions, when averaged over a year or longer, is small compared to variations in the sun’s electromagnetic radiation.

Scientists have noted these changes in the sun’s energy by observing from Earth’s surface for more than a hundred years, but were only able to begin to determine their magnitude and impact on Earth’s climate with more accurate measurements from space, starting in 1978 with measurements of the “total solar irradiance,” or TSI, made by NASA’s Nimbus 7 satellite.

Continue Learning: http://www.nasa.gov/content/goddard/new-instrument-continues-gathering-suns-effects-on-the-earth/#.UqD3dcSIx8E

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Astrophysicists tackle the Sun and one of physics’ biggest unsolved problems
Nov 18, 2013 by Beth Kwon

picture of the sun with a coronal hole (the large dark region at the bottom). Credit: NASA

picture of the sun with a coronal hole (the large dark region at the bottom). Credit: NASA

Daniel Wolf Savin and Michael Hahn have been fascinated by the universe since they were boys. For Savin, a senior research scientist in the Columbia Astrophysics Laboratory, discovering Albert Einstein at age 12 spurred the desire to “learn everything about the universe.” Years later, Hahn, an associate research scientist who grew up 40 miles from Savin’s home town in Connecticut, started gazing at the stars as a teenager; he eventually became president of the astronomy club at his alma mater, Carnegie Mellon.

Now the two have made a big leap toward cracking one of the biggest mysteries in astrophysics—why the corona, or plasma surrounding the sun, is so much hotter than the sun’s surface.

The coronal heating problem, as it is known, is important because the corona is the source of solar wind, which is responsible for the northern and southern lights and can also disrupt telecommunications and power grids. “Satellites can be slowly pushed out of their orbits if they’re deflected by the solar wind so if we can better understand the cause, we can create better models for space weather,” says Savin, referring to conditions beyond the atmosphere.

Continue Learning: http://phys.org/news/2013-11-astrophysicists-tackle-sun-physics-biggest.html

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