Wind-induced barotropic oscillations around the Saint Pierre and Miquelon archipelago (North-west Atlantic)
|Author(s)||Bezaud Marion1, Lazure Pascal1, Le Cann Bernard2|
|Affiliation(s)||1 : Ifremer, Laboratoire D'Océanographie Physique et Spatiale (LOPS), IUEM, Brest
2 : CNRS, Laboratoire D'Océanographie Physique et Spatiale (LOPS), IUEM, Brest
|Source||Continental Shelf Research (0278-4343) (Elsevier BV), 2020-04 , Vol. 195 , P. 104062 (19p.)|
|Keyword(s)||Barotropic modelling, Wind induced oscillations, Continental shelf wave, Saint Pierre and Miquelon archipelago, Newfoundland|
We investigate the nearly barotropic oscillations recently observed around the Saint Pierre and Miquelon (SPM) archipelago. They were recorded by two ADCPs at about 30 m depth during winter and spring 2014. These oscillations were the dominant signal on the currents with a period of 2 to 4 days. Our analysis shows that these oscillations were triggered by the wind. To investigate these oscillations, a 2D numerical model was implemented at a regional scale. The results from a realistic simulation confirmed the impact of wind forcing on ocean dynamics in the region. They also showed amplification of these oscillations around SPM, particularly in the north-west of the archipelago and near Burin Peninsula. Analyses suggested the influence of continental shelf wave dynamics at a ‘regional’ scale. This regional wave then triggers a ‘local’ scale continental shelf wave propagating anticyclonically around SPM in ∼2 days. Schematic modelling simulations with periodic wind stress forcing and relaxation after a gust of wind show a strong current response in this region with a wind stress periodicity centred around 2 days, which is attributed to resonance in the SPM area.