Discrimination of oil spills from newly formed sea ice by synthetic aperture radar

- We present a theoretical model of relative permittivity for oil/sea ice mixtures.
- We investigate multi-channel SAR measurements of oil and sea ice.
- SAR shows promise in discriminating oil/sea ice emulsions from unpolluted sea ice.
- A compound dielectric model of oil/seawater/sea ice mixtures is needed.

In this paper we examine the potential of multi-polarization SAR systems to detect and discriminate oil pollution from uncontaminated recently formed thin sea ice in the Arctic Ocean, where both oil and thin sea ice have similar low backscatter returns on SAR imagery. In this study, we present a theoretical model of the relative permittivity of oil-in-sea-ice mixtures and apply it to determine the effect of dielectric properties on the co-polarized backscatter ratio for sea ice, ocean, and oil. To support the theoretical discussion, we investigate available multi-polarization and multi-frequency SAR measurements. We compare SAR data collected over oil spills in seawater in the Gulf of Mexico and the North Sea with available similar data covering sea ice in the Arctic region. The results suggest that multi-polarization SAR systems will be useful to detect Arctic oil spills should a spill occur in new and young sea ice conditions, particularly in the marginal ice zones adjacent to the main polar ice pack.