Mesospheric Ice Clouds as Indicators of Upper Atmosphere Climate Change: Workshop on Modeling Polar Mesospheric Cloud Trends; Boulder, Colorado, 10–11 December 2009



The 20-year-old speculation that high-altitude summertime ice clouds (polar mesospheric, or noctilucent, clouds, here denoted MC) are affected by anthropogenic activities has recently received support from a 30-year time series of solar backscatter ultraviolet (SBUV) satellite measurements. SBUV data reveal a significant trend in bright MC properties. However, the robustness of the trend, extracted from interannual, local time, and solar cycle variability, and its underlying causes remains debatable.