Thread

1. herf · 1790117121 · focus · HN ↗

   Good post - the UV index is related to how short the "column of air" that the sun traverses to get to your skin - noon is the shortest distance. Scattering is a density function (more air, more scattering), so this is why it looks like cos^p when compared to normal irradiance (cos). It also explains why it is hard to get a sunburn in the temperate winter, since the sun always appears at an angle, it doesn't go directly overhead.

   1. saltcured · 1790117864 · focus · HN ↗

      As someone who has gotten sunburned in California winters and even around 7-9 PM in Alaska, I can't relate to your closing idea at all!

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