ERS SAR imaging of long period internal (tidal) waves

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Ermakov, SA (Author) Other; Da Silva, JC (Author) Other; Robinson, IS (Author) Other

Journal

Title: European Space Agency, (Special Publication) ESA SP

Pages: 1299-1304

ISSN: 0379-6566

Publisher: European Space Agency

Indexing

ISI Web of Knowledge

Scopus - 0 Citations

Other information

Authenticus ID: P-007-NH9

Abstract (EN): Short-period internal waves (TW) with wavelength O (1Km) are often seen in Synthetic Aperture Radar (SAR) satellite images of the ocean as systems of bright and dark parallel bands. Here it is shown that larger scale bands (10-20km) parallel to the shelf break, consistent with the structure of internal tides, are also observed. According to conventional hydrodynamic modulation models [Ref. 1, 2] internal tides should not be imaged by SAR, as the surface currents associated with tidal frequency internal motions are ineffective for modulating the short-scale wind waves responsible for the radar signal. Such models, however, did not take into account surface-active films, which are often present on the sea surface over the shelf zone. Here we present an analysis of the modulation of short-scale surface roughness caused by the redistribution of surface-active substances by tidal flow, in order to explain how SAR imaging of internal tides can occur.

Language: English

Type (Professor's evaluation): Scientific