This is a past event.

Environmental Engineering Graduate Seminar

Alden Adolph, Assistant Professor, Engineering Fundamentals and Mechanical and Aerospace Engineering, Michigan Technological University

Abstract

The naturally high albedo (or reflectivity) of snow provides a strong control on earth’s surface energy balance. Because of this critical role, accurately reproducing snow albedo is essential for effective climate modeling. Even in the Arctic, the already prevalent periods of wet snow are increasing due to more frequent rain on snow events and increased extent and duration of glacial surface melt; however, nearly all existing snow albedo models employ albedo schemes designed for dry snow. These models play a key role during snow melt because of the amplifying effects of the snow albedo feedback process, where melting snow leads to lower albedo, higher temperatures, and further snow melt. Therefore, explicitly incorporating the effects of liquid water content on snow albedo is a critical next step in improving model accuracy. This presentation will discuss analytical modeling and field observation approaches to quantifying the impact of liquid water on snow albedo. Preliminary results indicate that liquid water shifts spectral features in snow albedo due to differences in the imaginary index of refraction. Analytical modeling of wet snow shows that there is a roughly 3% increase in energy absorbed by the snowpack due to liquid water presence alone, without considering concurrent changes in grain shape and size due to melt. Improving our fundamental understanding of wet snow albedo can inform more accurate representation of snowmelt processes in climate models.  

Bio

Dr. Alden Adolph (she/her) received a BA and BE from Dartmouth College in Engineering Sciences with a concentration in Mechanical Engineering. She earned her PhD from Dartmouth in 2017 with a thesis titled “Snow and Firn: Impacts of Microscale Properties on Macroscale Climate Indicators.” She has studied gas transport in snow, snow albedo, and snow surface temperature using a variety of tools such as field observations, controlled experiments, modeling, and remote sensing. She has conducted fieldwork in seasonal snow for ten years and has been a part of three field research campaigns to the Greenland Ice Sheet. Prior to working at MTU, Alden was an Associate Professor of Physics at St. Olaf College in Northfield, Minnesota. Alden is originally from New Orleans, Louisiana and outside of her research and teaching, she enjoys spending time with her family, running, hiking, and cross country skiing.