* Reflection: Some UV rays do reflect off the ground, particularly from surfaces like sand, water, snow, and concrete. These surfaces have a higher albedo, meaning they reflect more light (including UV) than others.
* Absorption: Other surfaces, like grass and soil, absorb more UV rays than they reflect. This is why shade from trees or buildings provides better protection from UV than standing on a sandy beach.
* Wavelength: Different wavelengths of UV light behave differently. Shorter wavelengths (UVC) are mostly absorbed by the atmosphere and don't reach the ground. UVB rays can penetrate the atmosphere, and some are reflected, but most are absorbed. UVA rays are the longest wavelength and are more likely to be reflected, especially from snow and water.
Important Note: While UV rays can reflect off the ground, the amount of reflection varies depending on the surface and the wavelength of UV light. It's important to remember that even if you're in the shade, you're still exposed to reflected UV rays, particularly near water or snow.
