Drivers for the Formation and Variability of Ice Layers in the Mesopause Region

We provide an overview of the latest three Polar Mesospheric Cloud (PMC) seasons as seen by the Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) experiment: the northern 2007 and 2008 seasons as well as the southern 2007/2008 season. These PMC results will be based on an algorithm similar to the Solar Backscatter Ultraviolet instrument (SBUV) algorithm and thus they facilitate a comparison to concurrent and historical SBUV data. Correlations between PMC data and measurements of temperature and water vapor from different satellite instruments such as the Microwave Limb Sounder (MLS) are used to investigate mechanisms contributing to PMC variability. To evaluate our understanding of the forcing variables underlying these mechanisms, we will compare simulations of mesospheric meteorology from the Whole Atmosphere Community Climate Model (WACCM) to satellite measurements.