A climatology of UV radiation, 1979-2000, 65S-65N

Solar ultraviolet (UV) radiation reaching earth's surface is of interest because of its role in the induction of various biological and chemical processes, including skin cancer. We present climatological distributions of monthly mean surface-level UV radiation, calculated using the Tropospheric Ultraviolet-Visible (TUV) radiative transfer model with inputs of ozone column amounts and cloud reflectivities (at 380 nm) measured by satellite instruments (Total Ozone Mapping Spectrometers (TOMS), aboard Nimbus-7, Meteor-3, and Earth Probe). The climatology is averaged over the years 1979-2000 for UV-A (315 nm-400 nm), UV-B (280 nm-315 nm), and radiation weighted by the action spectra for the induction of erythema (skin-reddening), pre-vitamin D₃ synthesis, and non-melanoma carcinogenesis. Coverage is global, excluding the poles. Comparisons with concurrent ground-based UV radiation measurements archived at the World Ozone and Ultraviolet Data Center show agreement at the 10%-20% level, except at high latitudes where the large surface albedo of snow and ice invalidates the use of satellite-observed reflectivity in estimating cloud cover. The climatology may be useful in epidemiological studies that assess the role of long-term environmental exposure to UV radiation.