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

Combined Earth observations reveal the sequence of conditions leading to a large algal bloom in Lake Geneva

Damien Bouffard, Abolfazl Irani Rahaghi, Marco Toffolon, Oscar Rodrigo Sepúlveda Steiner, Rafael Sebastian Reiss, Frédéric Charles Soulignac

Freshwater algae exhibit complex dynamics, particularly in meso-oligotrophic lakes with sudden and dramatic increases in algal biomass following long periods of low background concentration. While the fundamental prerequisites for algal blooms, namely ligh ...

Springernature2024

Turbulence and Heat exchange in the Near-Surface Boundary Layer over Patchy Snow

Michael Haugeneder

The atmospheric layer adjacent to the earth's surface is of crucial importance for weather models due to the exchange of energy between the surface and the atmosphere. This exchange is dependent on the various surface properties and influences the state of ...

EPFL2024

Waterborne Virus Transport and Risk Assessment in Lake Geneva Under Climate Change

Tamar Kohn, Chaojie Li

Climate changes influence lake hydrodynamics and radiation levels and thus may affect the fate and transport of waterborne pathogens in lakes. This study examines the impact of climate change on the fate, transport, and associated risks of four waterborne ...

2024

Performance of energy piles foundation in hot-dominated climate: A case study in Dubai

Lyesse Laloui, Elena Ravera, Sofie Elaine ten Bosch

Energy piles represent an innovative technology that can help provide sustainable geothermal heating or cooling energy for thermal conditioning purposes. In hot-dominated climates, the interest is to inject heat in the ground and extract energy for space-c ...

Pergamon-Elsevier Science Ltd2024

Unraveling submesoscale processes associated with meso- and basin-scale gyres in Lake Geneva

Seyed Mahmood Hamze Ziabari

In large lakes, basin-scale gyres and submesoscale eddies, i.e., rotating coherent water masses, play a key role in spreading biochemical materials and energy throughout the basin, thereby significantly impacting water quality. Due to their transient and s ...

EPFL2023

Chimney‐Like Intense Pelagic Upwelling in the Center of Basin‐Scale Cyclonic Gyres in Large Lake Geneva

Ulrich Lemmin, David Andrew Barry, Rafael Sebastian Reiss, Mehrshad Foroughan, Seyed Mahmood Hamze Ziabari

Basin-scale quasi-geostrophic gyres are common features of large lakes subject to Coriolis force. Cyclonic gyres are often characterized by dome-shaped thermoclines that form due to pelagic upwelling that takes place in their center. At present, the dynami ...

2023

Numerical simulation of the fate, transport and public health risks of enteric viruses in Lake Geneva

Chaojie Li

Lakes are a fundamental feature of nature with brilliance, profoundness and complexity. Various of physical, chemical and biological changes take place three dimensionally in deep lakes, regulated by complicated boundary conditions. To understand and predi ...

EPFL2023

Natural slicks on Lake Geneva: From small-scale effects to large-scale formation and distribution

Mehrshad Foroughan

Low wind speeds (< 4 m/s) are ubiquitous in many water bodies, yet the physical processes occurring at the air-water interface in this range are poorly understood. A notable example is smooth patches on the water surface, known as natural slicks, formed wh ...

EPFL2023

Disentangling the effects of climate change and reoligotrophication on primary production in a large lake

Alfred Johny Wüest, Emile Barbe, Hugo Nicolás Ulloa Sánchez, Shubham Krishna

Climate change and reduction in nutrient loads have significant effects on primary production and phytoplankton growth dynamics. Since in the last few decades in many regions, nutrients in lakes were reduced simultaneously as the climate changed. Yet, it r ...

SPRINGER BASEL AG2023

Vertical distribution and seasonal dynamics of planktonic cyanobacteria communities in a water column of deep mesotrophic Lake Geneva

Natacha Tofield-Pasche, Stéphane Joost, Tamar Kohn, Charlotte Gisèle Weil, Oliver Michele Selmoni, Anna Carratala Ripolles, Coralie Chappelier, Hannah Elisa Chmiel, Annie Sandrine Guillaume

Background: Temperate subalpine lakes recovering from eutrophication in central Europe are experiencing harmful blooms due to the proliferation of Planktothrix rubescens, a potentially toxic cyanobacteria. To optimize the management of cyanobacteria blooms ...

Frontiers Media SA2023

Snow transport in extreme environments: from small to large scale modeling

Daniela Brito Melo

The cold regions on Earth, such as the polar and high mountain regions, are snow covered for at least a part of the year. These snow-covered surfaces are highly dynamic, particularly under the influence of strong winds. The aeolian or wind-driven transport ...

EPFL2023

Near-bed stratification controls bottom hypoxia in ice-covered alpine lakes

Damien Bouffard, Pascal Perolo, Tomy Doda, Nicolas Thomas Georges Escoffier, Janine Rüegg, Hannah Elisa Chmiel, Hugo Nicolás Ulloa Sánchez, Camille Roland Marie Minaudo

In ice-covered lakes, near-bottom oxygen concentration decreases for most of the wintertime, sometimes down to the point that bottom waters become hypoxic. Studies insofar have reached divergent conclusions on whether climate change limits or reinforces th ...

American Society of Limnology and Oceanography2023

Controlling factors of phytoplankton distribution in the river–lake transition zone of a large lake

David Andrew Barry, Matthieu Fallet, Frédéric Charles Soulignac

River–lake transition zones have been identified as major drivers of phytoplankton growth. With climate change reducing the frequency of complete lake overturns, it is expected that the Rhône River, the main tributary to Lake Geneva (France/Switzerland), w ...

2023

Basin-scale gyres and mesoscale eddies in large lakes: A novel procedure for their detection and characterization, assessed in Lake Geneva

Ulrich Lemmin, David Andrew Barry, Mehrshad Foroughan, Frédéric Charles Soulignac, Seyed Mahmood Hamze Ziabari

In large lakes subject to the Coriolis force, basin-scale gyres and mesoscale eddies, i.e. rotating coherent water masses, play a key role in spreading biochemical materials and energy throughout the lake. In order to assess the spatial and temporal extent ...

2022

Detecting submesoscale cold filaments in a basin-scale gyre in large, deep Lake Geneva (Switzerland/France)

Ulrich Lemmin, David Andrew Barry, Amir Mehdi Razmi, Seyed Mahmood Hamze Ziabari

Submesoscale filaments are a well-documented feature of oceanic flow fields. Based on the analysis of high-resolution 3D numerical simulations, field observations and remote sensing imagery, this study, carried out in Lake Geneva, Western Europe's largest ...

2022

Monitoring Mesoscale to Submesoscale Processes in Large Lakes with Sentinel-1 SAR Imagery: The Case of Lake Geneva

Ulrich Lemmin, David Andrew Barry, Mehrshad Foroughan, Seyed Mahmood Hamze Ziabari

As in oceans, large-scale coherent circulations such as gyres and eddies are ubiquitous features in large lakes that are subject to the Coriolis force. They play a crucial role in the horizontal and vertical distribution of biological, chemical and physica ...

2022

Density currents driven by differential cooling in lakes: occurrence, dynamics and implications for littoral-pelagic exchange

Tomy Doda

Cross-shore flows exchange water laterally in lakes, with ecological implications for the ecosystem. One example is the convective circulation induced by differential cooling, also known as the thermal siphon. This lateral flow forms when the sloping sides ...

EPFL2022

Flushing the Lake Littoral Region: The Interaction of Differential Cooling and Mild Winds

Damien Bouffard, Tomy Doda, Hugo Nicolás Ulloa Sánchez, Cintia Luz Ramon Casanas

The interaction of a uniform cooling rate at the lake surface with sloping bathymetry efficiently drives cross-shore water exchanges between the shallow littoral and deep interior regions. The faster cooling rate of the shallows results in the formation of ...

AMER GEOPHYSICAL UNION2022

Wind‐Induced Hypolimnetic Upwelling Between the Multi‐Depth Basins of Lake Geneva During Winter: An Overlooked Deepwater Renewal Mechanism?

Ulrich Lemmin, David Andrew Barry, Rafael Sebastian Reiss

Combining field observations, 3D hydrodynamic modeling, and particle tracking, we investigated wind-induced interbasin exchange between the Petit Lac (PL) (depth 75 m) and Grand Lac (GL) (depth 309 m) basins of Lake Geneva in early winter. Following a stro ...

2022

Convective regimes induced by surface cooling and topography in stratified waterbodies

Damien Bouffard, Tomy Doda, Hugo Nicolás Ulloa Sánchez, Cintia Luz Ramon Casanas

Gravitational convection plays a significant role in the ventilation, heat and mass distribution of aquatic systems. This study investigates thermally driven convection resulting from heat loss at the air-water interface during cooling periods in freshwate ...

Iahr-Int Assoc Hydro-Environment Engineering Research2022