Laura Sunberg, University of Colorado Boulder, Civil, Environmental, and Architectural Engineering Department and Institute of Arctic and Alpine Research, Boulder, United States, Julia Moriarty, University of Colorado Boulder, Department of Atmospheric and Oceanic Sciences and the Institute of Arctic and Alpine Research, Boulder, United States and Melissa Moulton, National Center for Atmospheric Research, Climate and Global Dynamics, Boulder, United States; Applied Physics Laboratory University of Washington, Seattle, United States