Internal Wave Features In The Northeast Atlantic As Imaged by SEASAT-SAR

This paper presents results derived from a study of some 5 million square kilometres of optical survey processed SEASAT-SAR imagery of the Northeast Atlantic. In the study, markings often attributed to internal wave activity were collated on maps which also showed the bathymetry and surface meteorology at the time of each pass. Two thirds of the satellite coverage of the area shows evidence of such internal wave activity. The markings occur in well over one hundred separate locations from Iceland to the Azores. Most appear to be associated with long wavelength, single mode packets. The features occur in conjunction with a wide combination of surface wind speeds and water depths. The paper classifies them according to wind speed, water depth, geographic location and clarity against the image background. The number of observations of internal wave activity has also been related to the number possible for each wind speed and water depth. This work confirms the capability of spaceborne SAR to observe internal wave effects and illustrates the advantage it offers for deriving features of the internal wavefield on a scale unattainable with shipborne measurements.