How is sea ice loss affecting clouds? A story about atmospheric stability in a warming Arctic

Ariel Morrison (1), Jennifer Kay (2)

Abstract
The multi-year record of combined CloudSat radar and CALIOP lidar data provides an unprecedented opportunity to observe the vertical structure, spatial and seasonal distribution, and phase of Arctic clouds. We use CloudSat and CALIOP data from 2007-2013 combined with complementary datasets (CERES, MODIS, AIRS, ERA Interim) to analyze the processes controlling clouds over the Beaufort, Chukchi and Siberian Seas, regions where recent sea ice loss has been particularly pronounced and where the mean state of the atmosphere has been relatively stable. We use shortwave radiation and lower tropospheric stability as analysis variables instead of traditional methods that rely on calendar dates and seasonal climatologies. Specifically, we are making scatterplots to assess the combined influence of sea ice concentration and atmospheric conditions on cloud properties (amount, height, phase, optical thickness, precipitation occurrence). Initial findings suggest that atmospheric stability is not the dominant control on Arctic cloud fraction over the Beaufort and Chukchi Seas during this time period. The influence of underlying surface ocean conditions on Arctic cloud properties depends on overlying atmospheric stability. Overall, this work seeks to quantify and understand cloud processes and impacts in a warming Arctic.