Current Events

  • Atmospheric CO2 Level Tops 400 ppm
    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm rep...Read more

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    Atmospheric CO2 Level Tops 400 ppm

    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well. The level of atmospheric greenhouse gases continues to increase, now over 120 ppm since the Industrial Revolution began. For more on the Keeling Curve, see http://keelingcurve.ucsd.edu/. Find out more about greenhouse gases and warming.
  • Massive Tornado Outbreak on Tornado Alley
    The week of May 19 brings dozens of tornadoes to Tornado Alley in the states of Oklahoma, Kansas, Io...Read more

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    Massive Tornado Outbreak on Tornado Alley

    The week of May 19 brings dozens of tornadoes to Tornado Alley in the states of Oklahoma, Kansas, Iowa, Illinois and Missouri. On May 20th, a massive tornado struck Moore, Oklahoma, devastating communities - destroying over 100 homes and hitting two elementary schools and a hospital - with many casualties and deaths. Our thoughts are with our friends and colleagues suffering from these storms. For more on the May 20th storms, see the NOAA Storm Prediction Center Storm Report.
  • Kansas Legislator Proposes Bill to Outlaw Sustainability Education
    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of ...Read more

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    Kansas Legislator Proposes Bill to Outlaw Sustainability Education

    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of sustainability. Here is a link to the one-page bill: http://www.kslegislature.org/li/b2013_14/measures/documents/hb2366_00_0000.pdf. See report on Bloomberg News.

Calcium Ions (Ca II K) in the Sun's Atmosphere

Calcium ion emits photonCalcium exists in small amounts in the solar atmosphere. Since atoms in the Sun's atmosphere are extremely hot, they move around very, very quickly. The atoms often collide, and such collisions can knock electrons loose from an atom. Atoms with missing (or extra!) electrons are called ions. A calcium (chemical element symbol Ca) atom that is missing one electron is called Ca II. Normal, neutral calcium is called Ca I.

Under conditions (temperatures around 10,000 kelvins) that exist in the Sun's upper photosphere and chromosphere, calcium loses 1 electron and becomes singly-ionized (Ca II). It then gives off light in the visible or near ultraviolet range at 393 nm (3,933Ĺ). Light at this wavelength is extremely faint but when the brilliant photospheric emissions are filtered out, the Ca II K line provides important information on the large-scale magnetic field structure in the chromosphere.

On Earth, calcium is a common gray metal that is found in chalk, limestone and the shells of mollusks. It is also crucial to the functioning of living organisms. It is essential for the growth of teeth and bones, helps control blood clotting and is used in transmitting messages along the body's nervous system.

Calcium II K emissions
Last modified May 14, 2010 by Randy Russell.

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