Premium
Analytic Formula for the Clear‐sky UV Index
Author(s) -
Madronich Sasha
Publication year - 2007
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2007.00200.x
Subject(s) - solar zenith angle , albedo (alchemy) , sky , radiative transfer , zenith , haze , column (typography) , environmental science , atmospheric radiative transfer codes , scale (ratio) , physics , remote sensing , computational physics , atmospheric sciences , meteorology , mathematics , optics , geometry , geology , connection (principal bundle) , art , quantum mechanics , performance art , art history
An approximate formula for the UV Index (UVI) under cloud‐free, unpolluted, low surface albedo conditions is:where μ o is the cosine of the solar zenith angle and Ω is the total vertical ozone column (in Dobson Units, DU). The dependence on μ o and Ω is based on a simple physical model of biologically weighted atmospheric transmission in the UV‐B and UV‐A spectral bands, with coefficients tuned to a detailed radiative transfer model, and is accurate to 10% or better over 0–60° and 200–400 DU. Other factors (clouds, haze, ground, etc. ) mostly conserve this dependence and scale simply.