The occurrence of ice production in slightly supercooled Arctic stratiform clouds as observed by ground‐based remote sensors at the ARM NSA site

Abstract Ice particle formation in slightly supercooled stratiform clouds is not well documented or understood. In this study, 4 years of combined lidar depolarization and radar reflectivity ( Z e ) measurements are analyzed to distinguish between cold drizzle and ice crystal formations in slightly supercooled Arctic stratiform clouds over the Atmospheric Radiation Measurement Program Climate Research Facility North Slope of Alaska Utqiaġvik (“Barrow”) site. Ice particles are detected and statistically shown to be responsible for the strong precipitation in slightly supercooled Arctic stratiform clouds at cloud top temperatures as high as −4°C. For ice precipitating Arctic stratiform clouds, the lidar particulate linear depolarization ratio ( δ par_lin ) correlates well with radar Z e at each temperature range, but the δ par_lin ‐ Z e relationship varies with temperature ranges. In addition, lidar depolarization and radar Z e observations of ice generation characteristics in Arctic stratiform clouds are consistent with laboratory‐measured temperature‐dependent ice growth habits.