Aerosol impacts on clouds are of particular importance in the Arctic, where clouds significantly modulate the energy budget at the rapidly-declining sea ice surface. However, quantifying the abundance and determining the key sources of aerosols that affect Arctic cloud formation, particularly those that impact the formation of cloud ice, remains a significant challenge. Here, I highlight several recent campaigns from our group at Colorado State University that aim to improve our characterization of major marine and terrestrial sources of aerosols that seed cloud ice in the Arctic.