Reconstruction of Interior Velocity and Density Fields from Satellite Surface Observations
Detta är ett förslag på examensarbete för kandidat- eller masternivå vid Institutionen för marina vetenskaper. Examensarbeten vid Institutionen för marina vetenskaper görs självständigt och bedöms individuellt.
Subject: Oceanography
Level and lenght: Bachelor’s (15hp) or Master’s (45-60 hp) thesis project
Supervisor: Anis Elyouncha
Co-supervisors: Göran Broström, Léon Chafik (Stockholm university)
Project Background
Understanding the three-dimensional (3D) structure of ocean currents and density fields is key to quantifying heat and salt transport, eddy dynamics, and large-scale circulation.
However, direct observations of subsurface velocity and stratification are sparse, typically limited to ship-based CTD and ADCP surveys. Satellite missions such as SWOT (Surface Water and Ocean Topography) now provide unprecedented high-resolution observations of sea surface height and other surface variables, which can potentially be used to infer subsurface structures through theoretical frameworks such as Surface Quasi-Geostrophy (SQG).
SQG theory links surface buoyancy anomalies to interior velocity and density fields, making it possible to reconstruct 3D fields from surface data. A systematic evaluation of these reconstructions against in situ ship data is necessary to assess the validity and limitations of this approach.
Project Description
This project will apply SQG theory to reconstruct subsurface velocity and density fields from satellite data and evaluate the method against ship-based and model datasets.
The student will:
- Use SWOT and other satellite surface data as input for SQG-based reconstruction of 3D velocity and density fields in the region between Iceland and the Faroe Islands.
- Compare reconstructed fields to available ship-based CTD and ADCP measurements, correcting the ADCP data for wind-driven and tidal components.
- Analyze the ability of SQG reconstructions to capture mesoscale eddy structures and their vertical extension.
- Test and validate the approach using model or reanalysis products provided by CMEMS as an additional reference.
This project will provide experience in combining theory, satellite remote sensing, in situ observations, and numerical data to address one of the key challenges in modern physical oceanography: linking surface observations to subsurface dynamics.
Skills Required
- Background in physical oceanography, fluid dynamics or remote sensing
- Programming and data analysis skills (Python, MATLAB).
- Familiarity with satellite oceanography (e.g., altimetry) is an advantage but not required.
- Experience with handling observational data (CTD, ADCP) is an advantage but not required.
Contact
Anis Elyouncha, Researcher
E-mail: anis.elyouncha@gu.se