[1] This paper reveals bands of enhanced levels of near-surface chlorophyll in the central Bay of Biscay in remotely-sensed images from the SeaWiFS ocean colour sensor, and shows that these are most probably associated with the crests of internal tidal waves travelling away from the shelf break. We are able to explain this effect as likely to result from the uplifting of a subsurface chlorophyll maximum by the passing internal tides, to such a level as may be ''seen'' by the satellite sensor, and have quantified the effect with a simple model. We believe this is the first time that internal tidal waves have been reported as having a direct and observable effect in such remotely-sensed ocean colour images.INDEX TERMS: 4544 Oceanography: Physical: Internal and inertial waves

[1] This paper presents new results showing that the Sofala shelf in the Mozambique Channel (20°S, 36°E) is a previously unknown ''hot spot'' for the generation of internal tides and internal waves. We investigate available Envisat advanced synthetic aperture radar imagery of the region, which is capable of showing the surface signatures of the internal waves. This is complemented by modeling of the ray pathways of internal tidal energy propagation, and of the P. G. Baines (1982) barotropic body force, which drives the generation of internal tides near the shelf break. The hot spot region is localized between 20°and 21°S because of the particular nature of the bathymetry there. Farther north and south, the forcing is reduced and insufficient to generate internal solitary waves in the synthetic aperture radar images. The analysis reveals two distinct types of internal wave trains that are observed traveling oceanward away from the shelf break, and we suggest that these result from direct generation at the shelf break and from ''local'' generation at about 80 km from the shelf break, respectively, because of the surfacing of internal tidal rays at the thermocline. Finally, we have investigated seasonal differences in the wave patterns, which penetrate more extensively into the channel during the southern summer and appear slightly farther to the south during the southern winter. We also conclude that the local generation process is more likely to occur during the winter when the stratification is reduced.

Synthetic Aperture Radar images revealed the two‐dimensional propagation characteristics of short‐period internal solitary waves in Race Point Channel in Massachusetts Bay. The images and in situ measurements of the flow in the channel are used to infer the likely generation mechanism of the waves. The solitary waves are generated during the ebb phase of the tide within the channel. On some occasions, two trains of internal waves are generated presumably at the same location but at slightly different phases of the ebb tide. The main characteristics of the (two‐layer) flow are described based on the criticality of the Froude number. It is suggested that these two individual packets of waves result from flow passage through resonance (where the Froude number is one). One packet is generated as the flow passes through the transcritical regime during the acceleration phase of the (ebb) tidal current, and another packet is generated during the deceleration phase. Both packets propagate upstream when the tide slacks, but with slightly different propagation directions.

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