Chlorophyll enhancement in the central region of the Bay of Biscay as a result of internal tidal wave interaction

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Muacho, S (Author) Other; da Silva, JCB (Author) FCUP; Brotas, V (Author) Other; Oliveira, PB (Author) Other; Magalhaes, JM (Author) Other

Journal

Title: Journal of Marine Systems

Vol. 136

Pages: 22-30

ISSN: 0924-7963

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 5 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-009-DWT

DOI: 10.1016/j.jmarsys.2014.03.016

Abstract (EN): A multi-sensor satellite approach based on ocean colour, sunglint and Synthetic Aperture Radar imagery is used to study the impact of interacting internal tidal (IT) waves on near-surface chlorophyll-a distribution, in the central Bay of Biscay. Satellite imagery was initially used to characterize the internal solitary wave (ISW) field in the study area, where the "local generation mechanism" was found to be associated with two distinct regions of enhanced barotropic tidal forcing. IT beams formed at the French shelf-break, and generated from critical bathymetry in the vicinities of one of these regions, were found to be consistent with "locally generated" ISWs. Representative case studies illustrate the existence of two different axes of IT propagation originating from the French shelf-break, which intersect close to 46 degrees N, - 7 degrees E, where strong IT interaction has been previously identified. Evidence of constructive interference between large IT waves is then presented and shown to be consistent with enhanced levels of chlorophyll-a concentration detected by means of ocean colour satellite sensors. Finally, the results obtained from satellite climatological mean chlorophyll-a concentration from late summer (i.e. September, when ITs and ISWs can meet ideal propagation conditions) suggest that elevated IT activity plays a significant role in phytoplankton vertical distribution, and therefore influences the late summer ecology in the central Bay of Biscay.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9