INVESTIGATING BIOLOGICAL RESPONSE IN THE UVB AS A FUNCTION OF OZONE VARIATION USING PERTURBATION-THEORY

In order to determine a biological response to ultraviolet radiation, calculations of biologically weighted dose rates are required, which i n turn involve the integral over wavelength of an action spectrum mult iplied by appropriate surface flux data. To determine a biologically w eighted dose rate accurately, a reasonable wavelength resolution is re quired, involving a full radiative transfer solution to be performed f or each wavelength in order to obtain the surface flux information. If biologically weighted dose rates are needed as a function of ozone va riation, then the number of radiative transfer solutions quickly makes a large number of ozone variations cumbersome. This paper shows that the perturbation theory developed for atmospheric radiative transfer b y Box and co-workers can predict surface fluxes and hence biologically weighted dose rates for a large range of ozone variations very effici ently. The method is then extended to calculate radiation amplificatio n factors. Results for biologically weighted dose rates are presented for a large range of solar zenith angles and ozone loadings using pert urbation theory and a full radiative transfer code and show that the p erturbation predictions never deviate very far from the radiative tran sfer solutions. (C) 1998 Elsevier Science S.A. All rights reserved.