Previous: Introduction Next: TOMS Satellite Data Up: Ext. Abst.

Ground-Based Measurements

Spectral measurements spanning several years are now available with well calibrated UV spectroradiometers from several sites.

Data from the groups responsible for data at the sites in Table 1 have been intercompared though an International effort to standardise ultraviolet spectroradiometry for a European Network (the SUSPEN intercomparison campaign in Greece in July 1997) and have been found to agree to within 2-3 % when corrections are applied to account for errors in the cosine response of the instruments . Data from the contributing groups were normalised to a common scale using the correction factors derived from this intercomparison campaign [Bais et al., 2000] and were provided in the form of daily doses of erythemally weighted UV irradiances [McKinlay and Diffey, 1987]. Measurements from the Brewer instruments (Greece and Canada) included small corrections to allow for the contribution to erythemal UV from wavelengths longer than the sampled region.

Table 1. Details of measurement sites

Previous: Introduction Next: TOMS Satellite Data Up: Ext. Abst.