Intraseasonal variability of nearshore productivity in the Northern Humboldt Current System: the role of coastal trapped waves
|Author(s)||Echevin Vincent1, Albert Aurelie1, Levy Marina1, Graco Michelle2, Aumont Olivier3, Pietri Alice4, Garric Gilles5|
|Affiliation(s)||1 : UPMC, CNRS, IRD, MNSN,IPSL,LOCEAN, F-75252 Paris, France.
2 : Inst MAR PEru IMARPE, Callao, Peru.
3 : Ifremer, Ctr Brest, UBO, CNRS,IRD,LPO, F-29280 Plouzane, France.
4 : Helmolz Ctr Ocean Res, Kiel, Germany.
5 : Mercator Ocean, F-31520 Ramonville St Agne, France.
|Source||Continental Shelf Research (0278-4343) (Pergamon-elsevier Science Ltd), 2014-02 , Vol. 73 , P. 14-30|
|WOS© Times Cited||18|
|Keyword(s)||Coastally trapped waves, Upwelling dynamics, Humboldt system, Intraseasonal variability, Primary productivity|
|Abstract||The impact of intraseasonal coastal-trapped waves on the nearshore Peru ecosystem is investigated using observations and a regional eddy-resolving physical-ecosystem coupled model. Model results show that intraseasonal variability over the period 2000–2006 represents about one fourth of the total surface chlorophyll variance and one third of the carbon export variance on the Peruvian shelf. Evidence is presented that subsurface nutrient and chlorophyll intraseasonal variability are mainly forced by the coastally trapped waves triggered by intraseasonal equatorial Kelvin waves reaching the south american coast, and propagate poleward along the Peru shore at a speed close to that of high order coastal trapped waves modes. The currents associated with the coastal waves induce an input of nutrients that triggers a subsequent phytoplankton bloom and carbon export. The impact of the local wind-forced intraseasonal variability on the ecosystem is of a similar order of magnitude to that remotely forced in the northern part of the Peru shelf on [50–90] day time scales and dominates over the entire shelf on [20–30] day time scales.|