Based on wintertime observations during the MOSAiC expedition in 2019-2020, it was found that Arctic cloud properties show significant differences when clouds are coupled to the fluxes of water vapor transport coming from upwind regions of sea ice leads. Among these differences are that cloud liquid water path is considerably increased as a function of lead fraction for observations of lead fraction above 0.02, whereas ice water path only shows some moderate level of dependency on lead fraction when deep precipitating clouds are considered. Cloud macro-physical properties like cloud base height and cloud thickness were found to be lower and thicker, respectively, for clouds coupled to the water vapor transport.

To substantiate the findings from the MOSAiC data set, long-term measurements (2012-2022) at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) at the North Slope Alaska (NSA) site in Utqiagvik, Alaska are being used to study the climatology of clouds and their properties coupled to the sea ice concentration in the Western Arctic. The same methodology used for the MOSAiC study is feasible to be applied to the NSA ARM site thanks to the standard instrumentation dataset provided by the ARM program. The study focuses on the atmospheric boundary layer topped water vapor transport as mechanism to link the influence of sea ice leads or polynyas, to the clouds. Statistical results will be presented and set into context to the results found for the MOSAiC expedition.