Estimating sublimation of intercepted and sub‐canopy snow using eddy covariance systems |
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| Authors: | Noah P Molotch Peter D Blanken Mark W Williams Andrew A Turnipseed Russell K Monson Steven A Margulis |
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| Institution: | 1. Department of Civil and Environmental Engineering, University of California, Los Angeles, California, 90095, USA;2. Department of Geography, University of Colorado, Boulder, Colorado, 80309, USA;3. Institute for Arctic and Alpine Research, University of Colorado, Boulder, Colorado 80309, USA;4. National Center for Atmospheric Research, Boulder, Colorado, 80305, USA;5. Department of Ecology and Evolutionary Biology;6. Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, USA |
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| Abstract: | Direct measurements of winter water loss due to sublimation were made in a sub‐alpine forest in the Rocky Mountains of Colorado. Above‐and below‐canopy eddy covariance systems indicated substantial losses of winter‐season snow accumulation in the form of snowpack (0·41 mm d?1) and intercepted snow (0·71 mm d?1) sublimation. The partitioning between these over and under story components of water loss was highly dependent on atmospheric conditions and near‐surface conditions at and below the snow/atmosphere interface. High above‐canopy sensible heat fluxes lead to strong temperature gradients between vegetation and the snow‐surface, driving substantial specific humidity gradients at the snow surface and high sublimation rates. Intercepted snowfall resulted in rapid response of above‐canopy latent heat fluxes, high within‐canopy sublimation rates (maximum = 3·7 mm d?1), and diminished sub‐canopy snowpack sublimation. These results indicate that sublimation losses from the sub‐canopy snowpack are strongly dependent on the partitioning of sensible and latent heat fluxes in the canopy. This compels comprehensive studies of snow sublimation in forested regions that integrate sub‐canopy and over‐story processes. Copyright © 2007 John Wiley & Sons, Ltd. |
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| Keywords: | vegetation canopy snow interception sublimation Rocky mountains eddy covariance |
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