Publications associées à Énergie d'inhibition de la convection

Supercell Thunderstorms in the Alpine Region - From Weather Radar Observations to Idealized Modeling

The high-impact nature and increasing occurrence of severe weather phenomena pushes forward research on their occurrence and improving our understanding thereof. Supercell thunderstorms are the focus of much severe convective research, as they represent on ...

EPFL2023

Unconfined Plunging of a Hyperpycnal River Plume Over a Sloping Bed and Its Lateral Spreading: Laboratory Experiments and Numerical Modeling

David Andrew Barry, Ulrich Lemmin, Koen Blanckaert, Haoran Shi

Hyperpycnal (negatively buoyant) river inflow into lakes and oceans often develops three-dimensional (3D) plunging flow patterns when laterally unconfined. To determine the 3D flow pattern characteristics, laboratory experiments of laterally unconfined plu ...

American Geophysical Union2022

Intercomparison of Large-Eddy Simulations of the Antarctic Boundary Layer for Very Stable Stratification

Etienne Gabriel Henri Vignon, Jing Huang

In polar regions, where the boundary layer is often stably stratified, atmospheric models produce large biases depending on the boundary-layer parametrizations and the parametrization of the exchange of energy at the surface. This model intercomparison foc ...

2020

LMDZ6A: The Atmospheric Component of the IPSL Climate Model With Improved and Better Tuned Physics

Etienne Gabriel Henri Vignon

This study presents the version of the LMDZ global atmospheric model used as the atmospheric component of the Institut Pierre Simon Laplace coupled model (IPSL-CM6A-LR) to contribute to the 6th phase of the international Coupled Model Intercomparison Proje ...

2020

Wintertime Coastal Upwelling in Lake Geneva: An Efficient Transport Process for Deepwater Renewal in a Large, Deep Lake

David Andrew Barry, Ulrich Lemmin, Andrea Cimatoribus, Rafael Sebastian Reiss

Combining field measurements, 3‐D numerical modeling, and Lagrangian particle tracking, we investigated wind‐driven, Ekman‐type coastal upwelling during the weakly stratified winter period 2017/2018 in Lake Geneva, Western Europe's largest lake (max. depth ...

2020

Absolute/convective secondary instabilities and the role of confinement in free shear layers

François Gallaire, Cristobal Manuel Arratia Martinez, Saviz Mowlavi

We study the linear spatiotemporal stability of an infinite row of equal point vortices under symmetric confinement between parallel walls. These rows of vortices serve to model the secondary instability leading to the merging of consecutive (Kelvin-Helmho ...

2018

Perturbations to the Spatial and Temporal Characteristics of the Diurnally-Varying Atmospheric Boundary Layer Due to an Extensive Wind Farm

Varun Sharma, Marc Parlange, Marc Calaf Bracons

The effect of extensive terrestrial wind farms on the spatio-temporal structure of the diurnally-evolving atmospheric boundary layer is explored. High-resolution large-eddy simulations of a realistic diurnal cycle with an embedded wind farm are performed. ...

Springer Verlag2017

Influence of atmospheric stability on wind-turbine wakes: A large-eddy simulation study

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation is combined with a turbine model to investigate the influence of atmospheric thermal stability on wind-turbine wakes. The simulation results show that atmospheric stability has a significant effect on the spatial distri ...

American Institute of Physics2015

The effect of atmospheric stability on wind-turbine wakes: A large-eddy simulation study

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation is used to investigate the influence of atmospheric stability on wind-turbine wakes. In the simulations, tuning-free Lagrangian scale-dependent dynamic models are used to model the subgrid-scale turbulent fluxes, while ...

IOP Publishing Ltd2014

Wind-Turbine Wakes in a Convective Boundary Layer: A Wind-Tunnel Study

Fernando Porté Agel, Corey Dean Markfort, Wei Zhang

Thermal stability changes the properties of the turbulent atmospheric boundary layer, and in turn affects the behaviour of wind-turbine wakes. To better understand the effects of thermal stability on the wind-turbine wake structure, wind-tunnel experiments ...

Springer Netherlands2013

Hydrology of the Sudanian Savannah in West Africa, Burkina Faso

Theophile Mande

As in all semi-arid regions, Tambarga, a small village surrounded by national parks in the landlocked country of Burkina Faso, is affected by the seasonality of the local hydrology. Seasonal and spatial variability of rainfall shapes the livelihoods of rur ...

EPFL2013

Role of data processing in measuring temperature gradients with DOE Schardin's schlieren #2

Pramod Rastogi, Sai Siva Gorthi

Flows having a variable fluid density can be visualized with optical methods. Recently, a background distortion technique, which can be considered a type of Schardin's schlieren #2, was proposed to study the refractive index variation in fluid and hence to ...

Elsevier2012

Diffusive-type of double diffusion in lakes - a review

Alfred Johny Wüest, Martin Schmid

This chapter is a contribution in honour of Gerhard H Jirka, who has been fascinated by the amazing variety of small-scale structures that nature surprises us with, particularly in stratified natural waters. Here, we focus on the diffusive regime of double ...

CRC Press2012

Statistical Analysis of Mountain Permafrost Temperatures

Evelyn Zenklusen Mutter

The consequences of climate change are clearly visible in the Swiss Alps. In the past decades, increasing air temperatures have induced pronounced glacier retreat and permafrost thawing. Thawing permafrost in steep terrain is a potential natural hazard, as ...

EPFL2012

Improving Alpine Flood Prediction through Hydrological Process Characterization and Uncertainty Analysis

Cara Christine Tobin

Among the many challenges of Alpine flood prediction is describing complex, meteo-hydrological processes in a simplified, robust manner that can be easily integrated into operational forecasting. In this dissertation, improved methods to characterize these ...

EPFL2012

A Simple Model for the Afternoon and Early Evening Decay of Convective Turbulence Over Different Land Surfaces

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

A simple model to study the decay of turbulent kinetic energy (TKE) in the convective surface layer is presented. In this model, the TKE is dependent upon two terms, the turbulent dissipation rate and the surface buoyancy fluctuations. The time evolution o ...

2011

Improved interpolation of meteorological forcings and hydrologic implications for a Swiss alpine region

Andrea Rinaldo, Alexis Berne, Cara Christine Tobin, Marc Parlange, Ludovico Nicotina

This paper presents a comparative study on the mapping of temperature and precipitation fields in complex Alpine terrain. Its relevance hinges on the major impact that inadequate interpolations of meteorological forcings bear on the accuracy of hydrologic ...

2011

Improving the Turbulence Coupling between High Resolution Numerical Weather Prediction Models and Lagrangian Particle Dispersion Models

Balazs Szintai

For the modelling of the transport and diffusion of atmospheric pollutants during accidental releases, sophisticated emergency response systems are used. These modelling systems usually consist of three main parts. The atmospheric flow conditions can be si ...

EPFL2010