Ozone and UV-B radiation anticorrelations at fixed solar zenith angles in southern Brazil

Anticorrelation behavior between total ozone column and UV-B radiation was observed for clear sky conditions during the year 2000 at the Southern Space Observatory OES/CRSPE/INPE – MCT (29.44°S, 53.82°W) located in the southern part of Brazil. To eliminate geometrical dependence of the solar angular position in relation to the instrument, UV-B radiation was measured at fixed solar zenith angles. The UV-B radiation (280-315 nm) was measured by an Eko Instruments model MS-210W radiometer, and total ozone column data was obtained by a Total Ozone Mapping Spectrometer on board of the NASA Earth Probe satellite. Correlation coefficients varied from R = -0.86 at 70° and 55°, to R = -0.97 at 40°. Ozone variations explained 74 to 94% of the UV-B variability. A 1% reduction in ozone resulted in an increase of about 1% in UV-B for the solar zenith angles studied.