| Summary: | The cryosphere consists of the frozen water and permafrost in the earth system. As a result of the current climate crisis, the cryosphere is undergoing major changes. The Arctic, containing important features of the cryosphere, is the fastest warming region in the world. Arctic glaciers and the Greenland Ice Sheet have started to experience an increase in mass loss rates leading to enhanced sea level rise contribution. Continued sea level rise through the 21st century will have wide-reaching impacts on the livelihoods of millions of people, especially those living in low-lying coastal areas. Understanding the different drivers of physical change in the Arctic is therefore important to accurately predict future climate conditions and identify effective climate justice policies. The Arctic mass loss is driven by temperature, albedo perturbations, and cloud cover and feedbacks. Some of the Arctic albedo change drivers are light absorbing particles (LAP), which include black carbon (BC), brown carbon (BrC), mineral dust, volcanic ash, and snow algae. However, observations of occurrence, sources, and magnitude of impacts of LAP across the cryosphere system remain scarce. Additionally, understanding the way LAP drive albedo changes is also underdeveloped. LAP radiative forcing is controlled by complex interactions and feedbacks over the Earth system that affect snow and cloud microphysics. This thesis expands the understanding of the LAP feedbacks and interactions in the cryosphere. The first part of this thesis characterizes LAP occurrence and its influence on snow albedo through the combined effect of surface darkening and snow metamorphism. Here, I find that LAP snow-aging feedback results in albedo reductions 3-8 times larger than previous studies associated with LAP alone have shown. In the second part, this thesis evaluates the connection between LAP and total particulate ability to enable the formation of ice crystals in clouds, or ice nucleation activity (INA). Although the glaciation in mixed-phase clouds, ...
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