What Drives the Salinity in the Global Ocean under Changing Climate Forcing? Responses in Climate-Models within an Experiment of a Model-Intercomparison Framework

• Main Author: Schreiber, Lukas
• Format: Thesis
• Language: English
• Published: 2023
• Subjects: Course of study: MSc Climate Physics; Antarctic; The Antarctic; Antarc*; North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/58629/; https://oceanrep.geomar.de/id/eprint/58629/1/Master_Thesis_Schreiber.pdf

The main aim of this thesis is to investigate the responses of the Ocean Salt Content (OSC) change to perturbed surface flux forcings and its spread across climate models within the Flux-Anomaly-Forced Intercomparison Project (FAFMIP) experiments. The decompostion of the OSC into different physical processes as contributions to vertical salt transport reveals that the resolved mean and parameterised eddy advection are the main drivers for change in OSC, which are also the main processes of the global vertical salt balance. The regions of change are mainly found in eddy energetic and frontal regions such as North Atlantic Subpolar Gyre, Western Boundary Currents (WBCs) or the Antarctic Circumpolar Current (ACC). However, these are the locations where inter-model spread are also largest for control simulation as well as for the simulations with the applied surface flux perturbations. The changes and spread of OSC responses to perturbed surface heat fluxes are strongest followed by the experiment with altered surface freshwater fluxes. The signals are weakest in the experiment with changed wind stress forcing.