ИСТИНА

Abstract: We examined the impact of different natural (solar activity, stratospheric aerosol, sea surface temperature) and anthropogenic (ozone depleting substances) factors influencing erythemal UV irradiance (Qery) via total ozone column and cloudiness changes over Northern Eurasia. The ozone and cloudiness variations based on the results of numerical experiments were estimated from 1979 to 2099 using a chemistry climate INM-RSHU model. We showed that the most significant natural factor influencing Qery variations is sea surface temperature (SST), which noticeably affects the atmospheric dynamics. Several numerical experiments with various SST datasets (MetOffice, ERA-Interim, SOCOL CCM) were fulfilled according to which we showed that the most significant changes in ozone due to the application of different SST datasets were observed in winter and spring. Annual total ozone column variations are about 15-20% due to different SST. The numerical experiment with the only change in ozone depleting substances according to Montreal protocol showed the ozone recovery and, as a result, Qery reduction, but this recovery is not linear. During the 2016-2020 period we estimated the 2-5% increase in Qery values relative to the baseline period (1979-1983) with about 6% maximum over Russian polar region. During the 2035-2039 period the Qery change against 1979-1983 period is about zero, during the 2055-2059 period we obtained the decrease of about 4-6% over Northern Asia and 6-8% over Northern Europe, which reached 15-20% during the 2095-2099 period. These changes corresponded to the noticeable boundary location shift of UV resources, which are determined according to (Chubarova, Zhdanova, 2013), almost for all skin types. For example, by the end of the 21st century in spring and summer the UV excess zone over northern seas will be partly replaced by the area which is characterized with the UV optimum conditions. In winter and autumn the areas with the UV deficiency conditions will be significantly increased for 1,2 and 4 skin types. References: Chubarova, N., Zhdanova, Ye. Ultraviolet resources over Northern Eurasia, Journal of Photochemistry and Photobiology B: Biology, 2013, 127, 38-51.