Simultaneous measurement of UV radiation received by the biosphere and total ozone amount

Abstract

We have made ground‐based measurements of solar ultraviolet (UV) irradiance with a double monochromator. The measurements are calibrated in absolute units and used to evaluate the temporal and spectral variation of the UV radiation received at the ground. We derive the column density of atmospheric ozone by fitting calculated UV irradiances to the measurements, and show that it is in basic agreement with the ozone amount inferred by a nearby Dobson spectrometer. We have thus demonstrated the feasibility of determining atmospheric ozone abundances and spectral ultraviolet irradiances simultaneously with a UV sensitive spectrometer and thereby providing the missing link between stratospheric ozone content and UV radiation received at the ground. In view of the present concerns about potential ozone depletions and related increases in UV radiation reaching the biosphere, we suggest that this procedure be used in the future to monitor the relation between atmospheric ozone amounts and UV radiation transmitted through the atmosphere. We also suggest that a combination of UV measurements and appropriate radiative transfer modeling be used to assess the effects of other environmental parameters such as clouds, aerosols, and ground albedo on the transmitted UV irradiance and to estimate the amount of UV radiation penetrating into the ocean.