The role of advection in the energy balance of late‐lying snowfields: Niwot Ridge, Front Range, Colorado

TLDR: In this article, measured profiles of temperature, humidity, and wind above alpine tundra are used as upwind boundary conditions in a numerical model for simulating turbulent transfer over late-laying snow.

Abstract: Measured profiles of temperature, humidity, and wind above alpine tundra are used as upwind boundary conditions in a numerical model for simulating turbulent transfer over late-laying snow. Resulting simulations indicate that (1) sensible heat flux comprises the major source of turbulent melt energy, although its relative importance vis-a-vis latent heat flux depends upon ambient weather conditions, and (2) advected heat contributes greatly to the energy balance of late-lying alpine snow. Near the leading edge of a snowfield, advection may contribute more than 30 MJ m−2 d−1 of melt energy on a very windy day and more than 12 MJ m−2 d−1 on a relatively windless day. The totals decrease to circa 5 MJ m−2 d−1 and 2 MJ m−2 d−1 at a distance of 1000 m from the leading edge. These findings suggest that the sensible heat flux may exceed net radiation as the major source of energy available for melting late-lying snow in windy alpine environments.