INFLUENCE OF DIFFERENT FACTORS ON THE ULT RAVIOLET AND BIOLOGICALLY-ACTIVE RADIATION

The sensitivity of UV fluxes in two spectral regions (lambda less than or equal to 320 nm and l less than or equal to 380 nm) and of biologi cally active ultraviolet radiation to the different procedures of calc ulations and to the changes of various atmospheric parameters has been studied by model simulations based on the delta-Eddington approximati on. Influence of major atmospheric parameters is not the same for diff erent spectral regions and becomes more pronounced with decrease in wa velength and with the growth of cloud optical thickness. Changes in bi ologically active radiation can exceed the effects of observed ozone t rends. Especially large attenuation of biologically active UV radiatio n and UV radiation with lambda less than or equal to 320 nm is observe d when the upper cloud layers become crystalline. The data obtained ca n be useful in the analysis of UV data measurements by different types of instruments especially in trend analysis and should be taken into consideration in the estimation of possible consequences of climate ch ange.