Département Eaux de surface

Lakes are traditionally perceived as systems dominated by vertical fluxes, with horizontal heterogeneities and transport often considered secondary. However, overlooking horizontal processes can lead to an incomplete understanding of lake dynamics. This research seeks to assess the influence of horizontal processes, particularly the role of sub-mesoscale structures, in shaping lake behavior. We aim to answer key questions: What types of horizontal structures are present in lakes? When should this spatial variability be accounted for? How can it be quantified?

Our study will concentrate on two primary sub-mesoscale processes: internal waves and eddies. We will explore their occurrence and characteristics, focusing on their role in influencing horizontal transport. This includes identifying the Lagrangian Coherent Structures (LCS) they generate. To achieve this, we will develop three-dimensional high-resolution numerical models of Lake Geneva, Lake Neuchâtel, Lake Zug, and Lake Lucerne, using the MIT General Circulation Model (MITgcm).