Satellite radar imagery of the coastal zone: slicks and oil spills

Olga Lavrova, Marina Mityagina, Tatiana Bocharova
Space Research Institute of Russian Academy of Sciences, Moscow, Russia
olavrova@mx.iki.rssi.ru

ABSTRACT

Detection of oil pollution is among of the most important goals of monitoring of a coastal zone. Satellite radar imagery appears to be the most adequate tool for this purpose because the data can be obtained at any time of day irrespective of the weather. Analysis of radar images is basically hampered by the problem of distinguishing between slicks (sea surface smoothing) of natural origin and spilt oil patches, especially in low wind conditions.

This work is based on radar images obtained by ERS-2 SAR and Envisat ASAR instruments. To raise reliability of oil pollution detection as well as to determine probable trajectory of oil patches, all available satellite data on the state of the sea surface and near-surface layer of atmosphere are additionally considered. The work summarises oil pollution monitoring experience in coastal zones of the Black Sea (Novorossiisk -Ghelendjik), Caspian Sea (Neftyanye Kamni) and Baltic Sea (Courish Lagoon – Gdansk Bay). Basic suggestions for the organization of satellite radar monitoring in any coastal zone are put forward.

Slicks of natural origin manifested in radar images as long bands of low backscatter signal are used to study vortex structures and currents. Vortices of hundreds to ten thousands of metres in diameter can be detected with the help of such slicks. We discuss the impact of wind, wave strength and the state of the near-surface layer of atmosphere on the possibility to study sea current vorticity using slick patterns in radar images.

Last Update: 2005-03-16