When do ultraviolet (UV) radiation levels, as noted by the EPA, typically peak regarding the sun’s position?
Answer
Around solar noon.
Ultraviolet (UV) radiation levels are highly dependent on the time of day because the amount of atmosphere the UV rays must pass through directly affects their penetration to the Earth's surface. The Environmental Protection Agency notes that these levels reach their maximum concentration when the sun is at its highest point in the sky, which corresponds to solar noon. This timing aligns with the shortest atmospheric path, allowing a greater percentage of biologically active UV rays, such as UVB, to reach the surface.
Related Questions
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