Feb 6, 2018

Humidity determines snowpack ablation under a warming climate

by
Adrian A. Harpold, Paul D. Brooks
,
Proceedings of the National Academy of Sciences
  • Uses long-term records from across the western United States to demonstrate that atmospheric humidity is a major control on how seasonal snow responds to warming temperatures
  • Demonstrates how atmospheric humidity and solar radiation interact with warming temperature to control snowpack ablation at 462 sites spanning a gradient in mean winter temperature from −8.9 to +2.9 °C
  • Observes an increase in the frequency and magnitude of episodic winter melt events under higher humidity that may alter the timing of water availability
  • Finds in lower-humidity regions, however, warming is associated with increased sublimation and/or evaporation from the snowpack further reducing the amount of available water in these dry regions