Moderation of Cloud Reduction of UV in the Antarctic Due to High Surface Albedo.

摘要: To gauge the impact of clouds on erythemal (sunburn causing) UV irradiances under different surface albedo conditions, measurements from two Antarctic sites (McMurdo and South Pole Stations) a midlatitude site (Lauder, New Zealand) are examined. The at remains high throughout year, McMurdo it has strong annual cycle, Lauder is low year. each divided into clear cloudy subsets compared with modeled clear-sky to assess attenuation by clouds. A radiative transfer model also used interpret observations. Results show increasing cloud optical depth, but can moderate this as result multiple scattering between base. This effect particular importance latitudes where snow may be present during summer months. There tendency toward greater solar zenith angle.