Measurement and modeling of diffuse ultraviolet radiation: A review

Area of Science:

• Environmental Science
• Atmospheric Physics
• Public Health

Background:

• Ultraviolet (UV) radiation comprises direct and diffuse components.
• Diffuse UV's proportion varies with atmospheric and surface conditions like clouds, aerosols, and albedo.
• Diffuse UV exposure significantly contributes to overall UV dose for humans.

Purpose of the Study:

• To review factors influencing diffuse UV exposure in human populations.
• To examine diffuse UV modeling techniques.
• To discuss broadband and spectral measurements of diffuse UV.

Main Methods:

• Literature review of factors affecting diffuse UV.
• Analysis of diffuse UV modeling approaches.
• Examination of measurement techniques for UV components.

Main Results:

• Diffuse UV is influenced by clouds, aerosols, albedo, Rayleigh scattering, and solar zenith angle.
• Diffuse UV can exceed direct UV, especially on cloudy or hazy days.
• Physical protection against diffuse UV is challenging due to its omnidirectional nature.

Conclusions:

• Diffuse UV radiation is a critical, often underestimated, component of total UV exposure.
• Current UV index reporting lacks specific diffuse UV information, potentially limiting public awareness and protection.
• Further research into diffuse UV modeling and measurement is essential for accurate risk assessment and public health guidance.