Non-scanning UV-(A&B) spectroradiometers of our own design have been deployed for long-term measurements at NDSC sites in both polar regions. Since 1997 spectral resolved UV-spectra are continuously recorded at Neumayer Station (Antarctica, 70.65°S, 8.25°W) and at Ny-Aalesund (Spitsbergen, 78.9°N, 11.9°E). Concerning some parameters which are important for UV radiative transfer the conditions differ significantly at these two stations. Due to the differences in the stability of the northern and southern polar vortex ozone depletion in spring is found only in some years at Spitsbergen whereas the Antarctic ozone hole can be observed every year over Antarctica. Our UV measurements are evaluated by taking into account total ozone data from ozone sondes and TOMS (Total Ozone Mapping Spectrometer) satellite data. To suppress the dominating influence of cloud variations on the UV radiative transfer, the ratio of the irradiation at two wavelengths (300nm/320nm), the so-called ozone index, is being used. By making use of the daily available TOMS data the expected anticorrelation of the ozone index and the total ozone could be verified. For the observation period the comparison of changes in the ozone index and total ozone for different years leads to a quantitative relation between the two measurands, the radiation amplification factor of total ozone. Apart from the different variability in total ozone, there is a distinctive seasonal variation in ground albedo and cloud cover at Spitsbergen, which is not found at Neumayer Station. These parameters are determinative for UV fluxes at the ground. A comparison of the datasets from the two sites will be presented.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL1-Processes and interactions in the polar climate system