Turbulence and mixing in the surface layer of the ocean is a significant element in the combined ocean-atmosphere system, and plays a considerable role in the transfer of heat, gas and momentum across the air-sea boundary. Furthermore, improving knowledge of the evolution of energy within the ocean system, both globally and locally, holds importance for improving our understanding of the dynamics of the ocean at large- and small-scales. As such, insight into turbulence and turbulent flows at the ocean surface is becoming increasingly important for its role in ocean-atmosphere exchange and, from a wider perspective, climate change. A research project was initiated to understand the role that spacecraft remote-sensing may play in improving observation of “turbulence” (in a broad sense) in the ocean, and for identifying how steps towards such observation may be made. An initial, exploratory study identified the potential benefit of Synthetic Aperture Radar in “bridging the gap” between in-situ and remote observations of O(10 m) turbulence and flows. A simulation procedure was followed to derive theoretical profiles of radar backscattering cross-section arising from a candidate flow field (that of the turbulent wake arising from a surface moving body) in order to postulate the role of instrument configuration and ambient conditions on visibility and resolvability of turbulent flow structure. The results demonstrate the potential to observe and characterise surface turbulent wake flows in terms of radar backscattering: a range of simulated backscatter images are presented for a turbulent surface current field derived from flow moving past a towed sphere, yielding investigation of the impact of turbulent currents on simulated radar backscattering. This has developed insights into the feasibility of resolving small-scale turbulence with remote-sensing radar and highlights the potential for extracting details of the flow structure and characteristics of turbulence near the surface of the ocean using current and future SAR capability.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:628704 |
| Date | January 2014 |
| Creators | George, Simon Gareth |
| Contributors | Tatnall, Adrian |
| Publisher | University of Southampton |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://eprints.soton.ac.uk/366507/ |
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