Publications de Rafael Sebastian Reiss

Identifying and quantifying unexpected deep zooplankton diel vertical migration in a large deep lake

Ulrich Lemmin, David Andrew Barry, Htet Kyi Wynn, Valentin Kindschi, Rafael Sebastian Reiss, Violaine Florette Piton

Diel Vertical Migration (DVM), a widespread zooplankton behavior in freshwater and marine systems, affects ecological interactions and biogeochemical cycles. In lakes, DVM has mainly been studied in the upper 50 m of the water column. However, based on aco ...

American Society of Limnology and Oceanography2025

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

Deepwater Renewal in a Large, Deep Lake (Lake Geneva): Identifying and Quantifying Winter Cooling Processes Using Heat Budget Decomposition

Ulrich Lemmin, David Andrew Barry, François Mettra, Rafael Sebastian Reiss, Naifu Peng

Wintertime deepwater renewal, which is important for heat-oxygen-nutrient exchange in lakes, is traditionally considered to be mainly driven by 1D vertical convective cooling. However, differential cooling between shallow and deep waters can produce densit ...

Amer Geophysical Union2024

Strong bottom currents in large, deep Lake Geneva generated by higher vertical-mode Poincaré waves

Ulrich Lemmin, David Andrew Barry, Rafael Sebastian Reiss

Although internal seiches are ubiquitous in large, deep lakes, little is known about the effect of higher vertical-mode seiches on deepwater dynamics. Here, by combining entire summer season current and temperature observations and 3D numerical modeling, w ...

Springer Science and Business Media LLC2024

What role does stratification play during winter in wind-induced exchange between the multi-depth basins of a large lake (Lake Geneva)?

Ulrich Lemmin, David Andrew Barry, Rafael Sebastian Reiss

Detailed studies of wind-driven interbasin exchange in lakes, focusing on the underlying driving forces and how they are affected by stratification, are presently lacking. We therefore investigated how strati-fication modifies wind-induced exchange between ...

2023

The role of submesoscale filaments in restratification of the surface mixed layer and dissolved oxygen variability in large Lake Geneva: field evidence complemented by Lagrangian particle-tracking

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

Theoretical studies on oceans and large lakes have shown that submesoscale instabilities in frontal zones tend to reduce horizontal density gradients and enhance vertical density gradients, thereby re-stratifying the Surface Mixed Layer (SML). Submesoscale ...

2023

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

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

Dynamics of wind-induced coastal upwelling and interbasin exchange in Lake Geneva during winter: Implications for deepwater renewal

Rafael Sebastian Reiss

Water quality in lakes is closely linked to hydrodynamics and often dominated by stratification, limiting the exchange between the epi- and hypolimnion. Thus, the vertical redistribution of biogeochemical tracers such as dissolved oxygen and nutrients by c ...

EPFL2021

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

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

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