Internal solitary waves in the Mozambique Channel: Observations and interpretation

• Type: Article in International Scientific Journal
• Date: 2009

Authors

da Silva, JCB (Author) Other; New, AL (Author) Other; Magalhaes, JM (Author) Other

Journal

Title: JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS

Vol. 114

ISSN: 2169-9275

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 56 Citations

Scopus - 57 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-003-KFA

DOI: 10.1029/2008jc005125

Abstract (EN): This paper presents new results showing that the Sofala shelf in the Mozambique Channel (20 degrees S, 36 degrees 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 degrees and 21 degrees 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12