Physikalischer Ozeanograph mit Schwerpunkt, numerische Modelle zur Erforschung der mesoskaligen und großskaligen ozeanischen Zirkulation zu verwenden und interdisziplinär an den Wechselwirkungen in der Geosphäre und mit der Biologie zu arbeiten.
Lagrangian Connectivity Studies in Ocean General Circulation Models – a powerful tool in physical oceanography with a wide range of interdisciplinary applications
The Lagrangian description of flow fields is a powerful tool to investigate the oceanic circulation, and to trace movements of, e.g., biological particles. Lagrangian approaches have been widely used in observational oceanography, and more recently gained relevance in assessing ocean general circulation models (OGCMs). Although the simulation of trajectories using OGCM velocity outputs in an offline mode is well established, the analysis of up to millions of individual pathways is typically limited to qualitative descriptions and basic statistics, such as the calculation of mean transports. In addition, results may be biased due to poorly represented influence of meso- and submesoscale processes. This project aims to assess and improve Lagrangian connectivity studies, using output of a hierarchy of realistically driven OGCMs, including eddy-resolving configurations. Particular focus will be on the spreading of water masses within the Atlantic Meridional Overturning Circulation. Amounts, pathways, and timescales of deep water masses originating in the subpolar North Atlantic and arriving in the subtropics will be identified and contrasted to those of surface and intermediate water masses from sources in the Southern Hemisphere. An important component will be the testing and application of the improved methodology on examples of biological connectivity. The project will be supervised by Arne Biastoch (GEOMAR) and will be incorporated within R11 “Predicted Ocean”. It will benefit from multidisciplinary expertise through collaboration with Thorsten Reusch (GEOMAR) in R8 “Evolving Ocean”, Steffen Börm (CAU Kiel) and Bruno Blanke (LPO, Brest, France).
Deciphering the Lost Years, novel in‐situ/silico tracking of neonate seaturtles
The dispersal of juvenile organisms drives the life-history evolution, dynamics and habitats of many endangered marine vertebrate populations. However, the movements/behaviours of small organisms, like hatchling sea turtles, remain enigmatic. We thus propose a novel interdisciplinary campaign to utilise advances in the miniaturisation of animal tracking devices and conduct the first multi-day hatchling tracking study to gain crucial information on their movements/swimming behaviours whilst dispersing offshore. Custom-made “hatchling shaped drifters” will also be released into the ocean to acquire in-situ Lagrangian data on surface currents experienced by hatchlings and to track passive dispersal trajectories. These observations will be analysed in-silico with currents and particle drift simulated using ocean models that resolve current variability down to length scales of c.10 km.
