On the dielectric properties and normalized radar cross-section of crude oil-contaminated sea ice
Neusitzer, Thomas David
This thesis explores the effects of crude oil spilled beneath young sea ice on the dielectric properties and normalized radar cross-section of the ice at microwave (C-band) frequencies. The dielectric profile, also referred to as the complex permittivity profile, of sea ice is a governing factor in how the ice scatters incident electromagnetic waves, thus affecting its associated normalized radar cross-section. The dielectric profile of sea ice is dependent on both the geophysical and thermal properties of the ice. Crude oil contained beneath, within, or on the surface of young sea ice was expected to change these properties, thus impacting both the dielectric profile and normalized radar cross-section of the ice. Differences between the dielectric profile and normalized radar cross-section of uncontaminated and oil-contaminated sea ice is expected to facilitate detection of oil-contaminated sea ice through active microwave remote sensing technologies. As such, a discussion of the geophysical, thermodynamic, and electromagnetic properties of sea ice is presented, as well as an overview of the behaviour of oil in ice infested environments and the efforts undertaken to detect crude oil-contaminated sea ice. Following this, the details of a preliminary laboratory experiment conducted to explore the differences in the dielectric profiles of uncontaminated and contaminated sea ice are presented. Next, a comprehensive description of the meso-scale crude oil-in-sea ice experiment and the results, including the modelled dielectric profiles and measured normalized radar cross-sections of uncontaminated and oil-contaminated sea ice, is provided. Finally, a simulation study comparing the normalized radar cross-section for the uncontaminated and oil-contaminated cases is presented. Based on the experimental and simulation work conducted, the observed differences in the temperature profiles and normalized radar cross-sections of uncontaminated and oil-contaminated sea ice suggest that differentiation between uncontaminated and oil-contaminated young sea ice using microwave remote sensing technologies may be possible.
Arctic remote sensing