2 Proposed Programme

Our measurements during 1990 identified low maximum polarisation of sky light and strong low-azimuth back-scattered light as two characteristic features of the Antarctic skies. We suggested in our analysis of these features that they came about by multiple reflections from the snow-ice surfaces surrounding the Tent Island site (and most of Antarctica). Our hypothesis was that the skies over the Dry Valleys would differ, since the amount of back-scattering would bevery much reduced. The two sites have essentially the same latitude, and the same unpolluted air, so a direct comparison should put in evidence the effects of surface albedo.

We planned to look for enhancement of UVB radiation at these sites associated with any ozone hole. We planned to study algae sensitivity to UV radiation.