Submitted to: Hydrology in Mountain Regions: Observations, Processes and Dynamics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2008
Publication Date: 2/1/2009
Citation: Reba, M., D. Marks, T. Link and J. Pomeroy, 2009, Inter-Annual Comparison of Measured Turbulent Fluxes over Snow at a Wind-Sheltered and Wind-Exposed Site Using Eddy Covariance. In: Hydrology in Mountain Regions: Observations, Processes and Dynamics,IAHS Publication 326, Center for Ecology and Hydrology, edited by Pomeroy, J. and MArks, D. p. 34-40.
Interpretive Summary: Snow makes up a significant portion of the precipitation received annually in the inter-mountain western US. Sensible and latent heat flux contribute to the melting of the seasonal snow cover. Some studies have shown that as climate warms, rain-on-snow events will become more common. These events are driven by large sensible and latent heat fluxes. This study reports measurements of sensible and latent heat fluxes at two contrasting sites for three consecutive years. Both fluxes are several magnitudes larger at the exposed site than at the sheltered site. These findings can be used to generalize sensible and latent heat flux contributions across the landscape.
Technical Abstract: Measurements of sensible and latent heat fluxes using eddy covariance (EC) instrumentation over snow in complex terrain have become more common in the past decade. Analysis of EC measurements at two sites, wind-exposed and wind-protected, for three consecutive years is presented. The analysis focused on how site conditions influence inter-annual variability of EC-measured turbulent fluxes. The protected site yields essentially the same turbulent fluxes, regardless of meteorological inter-annual variability. The exposed site yields turbulent fluxes that are several times the magnitude of the fluxes measured at the protected site. Sublimation for the season is relatively constant for the years studied, and hence constitute a larger percentage of the snow pack during below average water years. Sensible heat dominates the turbulent flux early in the season while latent heat dominates turbulent fluxes later in the season.