Spectral UV measurements in Austria from 1994 to 2006: investigations of short- and long-term changes

S. Simic (1) , P. Weihs (1) , A. Vacek (1) , H. Kromp-Kolb (1) , M. Fitzka (1)

1 Institute of Meteorology

Influences of atmospheric variability on short- and long-term changes of spectral UV irradiance measured at the Sonnblick observatory (47.03 N, 12.57 E, 3106 m) during the period from 1994 to 2006 is studied. Measurements are performed with a Brewer ozone single spectrophotometer and with a Bentham DM150 spectroradiometer (double monochromator). The influence of ozone, albedo and clouds on UV variability is evaluated separately using 10-year climatology. It is found that the effect of total ozone on short-term variability of UV irradiance at 305 nm can be more than 200% and on average more than 50%. Clouds can cause variability of 150% or more and on average 35%. Variability caused by albedo is maximum 32%. Long-term trends are investigated for the time period from 1994 to 2006 using the non-parametric Mann-Kendall trend test. Significant downwards trends (99% confidence level) were found for solar zenith angle 55° at wavelengths from 305 nm to 324 nm and CIE.

Domaines: Océan, Atmosphère

S. Simic, P. Weihs, A. Vacek, H. Kromp-Kolb, M. Fitzka. Spectral UV measurements in Austria from 1994 to 2006: investigations of short- and long-term changes. Atmospheric Chemistry and Physics Discussions, 2008, 8 (1), pp.2403-2428. ⟨hal-00303964⟩