The effects of summer snowfall on Arctic sea ice radiative forcing

• Main Author: Chapman-Dutton, Hannah
• Other Authors: Webster, Melinda, Sturm, Matthew, Ballinger, Thomas, Zweiback, Simon
• Format: Thesis
• Language: English
• Published: 2023
• Subjects: Sea ice; Arctic Ocean; Radioactive forcing; Albedo; Snow; Master of Science in Geosciences; albedo; Arctic; Alaska
• Online Access: http://hdl.handle.net/11122/14945

Thesis (M.S.) University of Alaska Fairbanks, 2023 The decline in Arctic sea ice has had major impacts on the climate system, particularly relating to the ice-albedo feedback. Since fresh snow on top of bare or melting sea ice increases the surface albedo on local scales, the impact of summer snow events can have a negative radiative forcing effect, which could inhibit sea ice surface melt. In this study, we compared snow depth and meteorological data from buoys and satellite retrievals of surface and atmospheric conditions to identify and characterize summer snow accumulation case studies across the Arctic from 2003 to 2017. Clouds and Earth's Radiant Energy System (CERES) retrievals were used to quantify the changes in surface albedo before and after the snow accumulation events. Information from these case studies was then scaled up to find similar events on a pan-Arctic scale using a Lagrangian sea ice parcel database. In this way, we characterized the frequency, magnitude, and duration of summer snow accumulation events similar to those observed by buoys. Finally, a simple radiative transfer model was used to quantify the impact of summer snowfall events on the surface and top-of-atmosphere radiative forcing over the entire Arctic region. The following work provides new information on observed snow accumulation events over Arctic sea ice in summer by combining multiple sources of in situ, satellite, and modeled data. Such results will be particularly useful in understanding the impacts of ephemeral summer weather on surface albedo and their propagating effects on the radiative forcing over Arctic sea ice.