[ESAC Seminar] Paul Nicknish

“Simple Models for Seasonal Snowpack Variability and Their Climate Sensitivity”

Wintertime accumulation of mountain snow and its delayed melt-off in spring and summer sustains vital ecosystems and annually replenishes water reserves for almost two billion people around the world. Mountainous regions have been shown to be particularly sensitive to climate warming, and thus understanding the interactions between meteorological variability and seasonal snow accumulation is essential for grasping how this critical resource might change in the future.

This work combines a simple model of seasonal snowpack dynamics with in situ observations from the western US to better understand how weather variability is integrated into variations in snow water equivalent (SWE). In the model, snow accumulates when precipitation falls at temperatures below  0°C, and ablation is modeled with a time-dependent degree-day factor. We find that neglecting winter ablation entirely in the model results in the best fit to the observations. We then analytically demonstrate a relationship between annual maximum SWE, winter-mean precipitation rate, and frozen season length; the product of these two quantities does a good job of capturing both interannual and geographic variability in annual maximum SWE.

This modeling framework can be used to assess the sensitivity of seasonal snowpacks to climate change and allows for a clear understanding of two potentially competing effects on snowpack development: a shortened accumulation season and increasing precipitation intensity with warming.

ESAC Early-Career Seminar Series —

A forum for students and postdocs to share recent research, hone presentation skills, and build community among peers, sponsored by the EAPS Student Advisory Committee. Open to current EAPS graduate and undergraduate students and postdocs. Typically hosted on Thursdays during the semester, including pizza lunch.

Contact: esac.officers@gmail.com