@inproceedings{fdi:010078256,
  title = {{H}ow does the low-frequency {E}quatorial {K}elvin {W}ave activity, local ocean stratification, and coastal winds modulate the south-eastern interannual {A}tlantic variability ? [r{\'e}sum{\'e}]},
  author = {{B}achelery, {M}.{L}. and {I}llig, {S}erena and {R}ouault, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he objective of this study is to describe the low-frequency modulation of the {E}quatorial {K}elvin {W}ave ({EKW}) activity in the tropical {A}tlantic as well as the low-frequency modulation of the local stratification and coastal winds along the coast of south-western {A}frica. {W}e aim at investigating the control of these forcings in modulating the oceanic interannual variability off the coasts of {A}ngola/{N}amibia and the phenomenology of {B}enguela {N}iño/{N}iña events. {T}he methodology is based on the development of a high resolution (1/12°) long-term (1958 - 2008) numerical simulation of the {S}outh-{A}tlantic {O}cean using the {R}egional {O}cean {M}odeling {S}ystem ({ROMS}). {T}he evaluation of the model performances show that the model is skilful in reproducing the mean state and the interannual variability. {T}he evaluation of the equatorial forcing reveals a low-frequency modulation of the {EKW} activity with a significant reduction of the {EKW} energy from 1958 to 1990, then re-energized up to 2008. {V}ariations are associated with change in {EKW} baroclinic mode contribution to interannual sea level anomalies: from 1958 the second baroclinic mode dominate, and is then balance by the third baroclinic mode after the late 1990's. {C}oncomitantly, further analyses show a decrease of the wind stress forcing and a modulation of the magnitude of wind projection coefficients according to the oceanic baroclinic modes in the {G}uinea gulf with in particular a strong increase of the third {EKW} mode. {C}hanges are associated with the increase (decrease) of the intensity (maximum depth) of the equatorial stratification. {O}ur results suggest that the change in the remote equatorial forcing may play an important role in the modulation of the variability off the coasts of {S}outh-{W}est {A}frica. {T}hese results will be confronted to the low frequency modulation of local wind variations and {C}oastal {T}rapped {W}aves ({CTW}) signature due to different stratification state along the south-eastern coast of {A}frica. {I}ndeed, modulation of the coastal stratification will most likely impact the characteristics of {CTW} propagation and their efficiency to imprint the coastal interannual variability in the {B}enguela {U}pwelling {S}ystem.},
  keywords = {{AFRIQUE} {SUBSAHARIENNE} ; {ANGOLA} ; {NAMIBIE} ; {ATLANTIQUE}},
  numero = {},
  pages = {63},
  booktitle = {{I}nternational conference {ICAWA} 2017 and 2018 : extended book of abstract : the {AWA} project : ecosystem approach to the management of fisheries and the marine environment in {W}est {A}frican waters},
  year = {2019},
  ISBN = {978-9553602-0-06},
  URL = {https://www.documentation.ird.fr/hor/fdi:010078256},
}