Climate models have long struggled to accurately simulate both present-day and future cloud properties in polar regions, particularly low-level mixed-phase clouds. These clouds present unique challenges due to their composition of both liquid droplets and ice crystals, their close interaction with heterogeneous surfaces, and their governance by large- and cloud-scale dynamics. As a result, climate models must not only incorporate advanced microphysical parameterizations but also capture the full range of interactions and feedbacks among clouds, turbulence, surface fluxes, aerosols, radiation, and large-scale transport processes that drive the life cycle of low-level clouds. In this project, our efforts isolate and identify a poorly understood process that may significantly impact cloud representation in models – the subgrid processes associated with sea ice leads and their coupling with low clouds, particularly during non-summer seasons.

The Arctic has become emblematic of climate change, yet major uncertainties consistently persist in our ability to understand and predict Arctic climate, particularly concerning the radiative effects of clouds. By leveraging active satellite cloud observations from radar and lidar, we aim to quantify the full spectrum of radiative effects of Arctic low clouds, providing a comprehensive understanding of their radiative influence at the surface, atmosphere column, and TOA.

Sea ice leads (cracks) play a crucial role in the Arctic boundary layer as they contribute ~50% of heat loss from the ocean to the atmosphere in winter pack ice regions, thereby affecting boundary layer cloudiness and structure. Given that Arctic low clouds have a first-order impact on the surface energy budget and sea ice cracks are likely to become more frequent in a new Arctic, it is imperative to understand the modulators of these clouds, such as sea ice leads. In this work, we aim to address two key questions: What is the influence of sea ice leads on low cloud properties during the wintertime, when large surface-air temperature differences exist? And what physical mechanisms govern the interactions between leads and low-level clouds? These efforts aim to identify previously overlooked processes related to lead-cloud coupling, which are critical to advancing our understanding of the complex Arctic system and its climate.