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| Titel |
Observed effects of soil moisture on surface fluxes and slope winds in an alpine valley |
| VerfasserIn |
Megan Daniels, Eric Pardyjak, Wilfried Brutsaert, Daniel Nadeau, Susana Fernandez-Vidal, Guillermo Barrenetxea, Marc Parlange |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053266
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| Zusammenfassung |
| Soil moisture affects flow in the atmospheric boundary layer through the relative partitioning
of energy into the surface sensible and latent heat fluxes. While this effect has been
well-studied over flat terrain through both field experiments and simulations, in complex
terrain it has previously only been investigated through simulations. In the current study, we
use observations to investigate effects of surface soil moisture on the strength and onset of
buoyancy-driven slope winds following the diurnal cycle in an alpine valley. In the summers
of 2009 and 2010, the Val Ferret catchment (~20 km2) in southern Switzerland was
instrumented with surface weather stations measuring wind speed and direction (2 m), soil
moisture, surface skin temperature, air temperature (2 m), humidity (2 m), incoming solar
radiation, and precipitation. Results indicate that on calm, cloudless days, increased
soil moisture leads to weaker up-slope and up-valley winds. This is corroborated
through the calculation of surface sensible and latent heat fluxes using Monin-Obukov
similarity theory, which shows that increased soil moisture leads to increased latent heat
fluxes and correspondingly decreased sensible heat fluxes at stations within the
valley. |
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