For example in Perth, WA today the UV was only “1 – Low” at 6pm, when the sun was still quite high in the sky. The temperature was still 34 degrees and you could really feel the sun’s heat.
How could you be at such low risk of sunburn under those conditions?
In: Planetary Science
Hey Perth! It’s the angle of the sun at 6pm. Think of the atmosphere like a thick blanket. At noon, the light of the sun is coming straight down, so it pierces through the atmosphere via the shallowest path. After mid-day, the light comes from an angle, and so the depth of the atmosphere it has to cross is larger; this allows for more scattering due to whatever particulates are in the atmosphere, so less UV intensity. This is also why “dusk” feels like less intense and colored light.
I miss that Perth sunshine.
I bet if you looked back at the UV at noon, it’ll be much higher.
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