Summary
Measurements of UV irradiance were collected near Davis Station (68.58o S, 77.97o E), East Antarctica during November/December 1997 in order to examine the effect of inhomogeneous surface albedo on UV irradiance. Measurements were taken in transects perpendicular to an ice/water boundary, while one instrument continuously measured at the ice edge. Irradiances along the transects were normalised by coincident measurements at the ice edge and converted into ratios. Systematic differences in downwelling surface irradiance were observed over the high reflective surface and open water near the ice edge. For cloudless conditions, the relative change in irradiance reached a constant value of ~ 5% at a distance of 2.5 km from the ice edge, both over water and snow. In overcast conditions, much higher relative changes in irradiance were observed (reaching ~ 30% at a distance of 2.5 km from the ice edge on 17 November 1997) with no sign of a constant relative change being reached.