Publications de Chad Higgins | EPFL Graph Search

Attenuation of wind-induced pressure perturbations in alpine snow

Wolf Hendrik Huwald, Marc Parlange, Chad Higgins

Windpumping has been identified as a process that could potentially enhance sublimation of surface snow at high forcing frequency and spawn air movement deeper in firn at lower frequencies. We performed an experiment to examine the relationship between hig ...

International Glaciological Society2016

Buoyant Turbulent Kinetic Energy Production in Steep-Slope Katabatic Flow

Marc Parlange, Chad Higgins, Holly Jayne Oldroyd, Eric Richard Pardyjak

We develop several critical concepts that should be considered when interpreting, modelling and designing future experiments for flows over sloping terrain. Vertical buoyancy fluxes in katabatic flows can be positive and a source of turbulent kinetic energ ...

Springer Verlag2016

Large Wind Farms and the Scalar Flux over an Heterogeneously Rough Land Surface

Marc Parlange, Chad Higgins, Marc Calaf Bracons

The influence of surface heterogeneities extends vertically within the atmospheric surface layer to the so-called blending height, causing changes in the fluxes of momentum and scalars. Inside this region the turbulence structure cannot be treated as horiz ...

Springer Verlag2014

Are atmospheric surface layer f lows ergodic?

Valentin Simeonov, Marc Parlange, Gabriel George Katul, Chad Higgins, Martin Froidevaux

The transposition of atmospheric turbulence statistics from the time domain, as conventionally sampled in field experiments, is explained by the so-called ergodic hypothesis. In micrometeorology, this hypothesis assumes that the time average of a measured ...

American Geophysical Union2013

Flow during the evening transition over steep Alpine slopes

Wolf Hendrik Huwald, Marc Parlange, Chad Higgins, Daniel Nadeau, Eric Richard Pardyjak

A field campaign, the Slope Experiment near La Fouly (SELF-2010), was conducted to monitor the evening transition of slope flows on clear-sky days from July to September 2010 in a narrow valley of the Swiss Alps. A steep west-facing slope with inclinations ...

Wiley-Blackwell2013

Measured and Estimated Water Vapor Advection in the Atmospheric Surface Layer

Valentin Simeonov, Marc Parlange, Chad Higgins, Martin Froidevaux, Eric Richard Pardyjak

The flux of water vapor due to advection is measured using high-resolution Raman lidar that was orientated horizontally across a land-lake transition. At the same time, a full surface energy balance is performed to assess the impact of scalar advection on ...

American Meteorological Society2013

Evaporation from a shallow water table: Diurnal dynamics of water and heat at the surface of drying sand

Marc Parlange, Ivan Lunati, Chad Higgins, Scott W. Tyler

Accurate estimates of water losses by evaporation from shallow water tables are important for hydrological, agricultural, and climatic purposes. An experiment was conducted in a weighing lysimeter to characterize the diurnal dynamics of evaporation under n ...

Amer Geophysical Union2013

Thermal diffusivity of seasonal snow determined from temperature profiles

Wolf Hendrik Huwald, Marc Parlange, Chad Higgins, Holly Jayne Oldroyd

Thermal diffusivity of snow is an important thermodynamic property associated with key hydrological phenomena such as snow melt and heat and water vapor exchange with the atmosphere. Direct determination of snow thermal diffusivity requires coupled point m ...

Elsevier2013

Similarity Scaling Over a Steep Alpine Slope

Marc Parlange, Chad Higgins, Eric Richard Pardyjak, Daniel Nadeau

In this study,we investigate the validity of similarity scaling over a steep mountain slope (30–41◦). The results are based on eddy-covariance data collected during the Slope Experiment near La Fouly (SELF-2010); a field campaign conducted in a narrow vall ...

Springer2013

A Raman lidar to measure water vapor in the atmospheric boundary layer

Hubert van den Bergh, Valentin Simeonov, Marc Parlange, Chad Higgins, Martin Froidevaux, Eric Richard Pardyjak, Pablo Roberto Ristori, Ilya Serikov

A new multi-telescope scanning Raman lidar designed to measure the water vapor mixing ratio in the atmospheric boundary layer for a complete diurnal cycle with high resolution spatial (1.25 m) and temporal (1 s) resolutions is presented. The high resolutio ...

Elsevier2013