Climate Dynamics Group
at the University of California, Santa Cruz

Poleward moisture transport into the Arctic occurs via short-lived, episodic intrusions of warm, moist air masses. These extreme transport events are associated with an enhanced greenhouse effect that is expected to slow sea-ice growth in winter and hasten the start of spring melt season. Yet, their impact on the Arctic energy balance averaged over longer time scales has been difficult to quantify, in part due to the challenge in separating local and remote Arctic moisture sources. We implement numerical water tracers and source-aware radiative locking in an Earth system model to reveal how moist intrusions and their vertical structure sustain water vapor and cloud feedbacks over the Arctic and thereby elicit sea ice retreat and its attendant feedbacks. This research is supported by the Department of Energy under Award DE-SC0023070.