Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Measuring Solar UV on earth ?

  1. Jun 4, 2015 #1
    Is solar uv completely blocked from reaching earth or do we just need more sensitive uv detectors to make ground-based observations? In particular of the uv wavelengths corresponding to hydrogen Lyman series lines.
     
  2. jcsd
  3. Jun 4, 2015 #2

    Chronos

    User Avatar
    Science Advisor
    Gold Member

    Sunburns offer compelling evidence that some fraction of solar UV does reach the ground. The atmosphere screens out most, but not all UV radiation. I suspect some radiation at these wavelengths is visible in the Lyman series, but, most is in the Balmer series.
     
  4. Jun 4, 2015 #3
    Thanks - the reason I asked because we've got a whole lot of fancy hardware up in space examining distant stars and galaxies yet the data on our very own special star, the sun is pretty woeful as far as I can make out. I have researched sources of solar Lyman Alpha and Lyman Beta profiles and so far the best I can find is Artzner's 1978 profile and Lyman Beta extracted via 'densitometry' from Tousey's early rocket based observations. I would like to see Artzner's very careful profile at higher resolution. I would like to see what's going on in the small dips you see in left and right peaks. I would like to have a precision measurement of a key reference wavelength namely the geo-coronal absorption rather than seeing attempts to whitewash it out of the picture possibly compromising the profiles. I would also like to see precision measurements on the separation of the peaks in these profiles. Does that vary? Should it vary ? Do we need to be very careful where we measure (ie at disk centre of "quiet sun" rather than in wavy limb filaments or whatever) ?
     
  5. Jun 4, 2015 #4

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    If you're not too clear on how UV radiation affects the earth and things living on the surface, you should peruse these fact sheets from the US EPA:

    http://www.epa.gov/sunwise/doc/uvradiation.html

    After all, sun tans do not come solely out of a bottle.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Measuring Solar UV on earth ?
Loading...