UVB irradiance and atmospheric optical depth at the Dead Sea basin, Israel: Measurements and modeling

An attempt has been made in this study to parameterize the three solar UVB radiant components, namely, direct, global and diffuse as a function of both UVB optical depth (δ) and relative optical air mass (ma). The available measurements of direct and global UVB irradiance components enable one to determine first the UVB optical depth of a real atmosphere. That is, the normal incident UVB irradiance was expressed as a function of the optical depth and relative air mass using Bouguer's law; whereas, the global UVB irradiance component was utilized to obtain the UVB optical depth through a modified version of the Lambert–Beer's law. The parameterization schemes of both direct and global UVB components are validated against independent data set, whereas the diffuse UVB component was obtained as the difference between the above radiant components. The parameterization schemes have been applied for both clear and all sky's conditions. Moreover, results obtained through the proposed parameterization schemes revealed adequate predictions for the three UVB radiant components.

► Bouguer's law correlates normal incidence UVB with optical depth and air mass.
► Turbid atmosphere optical depth determined using global and normal incidence UVB measurements.
► A parameterization procedure was used to parameterize normal incidence UVB as a function of air mass.
►  The same procedure was applied to both global and diffuse UVB.