@article{fdi:010093601,
  title = {{S}patial and temporal variability of hydrodynamics on the {A}mazon {C}ontinental {S}helf : an observational approach},
  author = {de {F}reitas, {P}. {P}. and {C}irano, {M}. and {T}eixeira, {C}. {E}. {P}. and {M}elres, {S}. {J}. {R}. and de {S}ousa, {A}kcd and {G}omes, {V}. {J}. {C}. and {G}uerrero-{M}artin, {C}. {A}. and {K}och {L}arrouy, {A}riane},
  editor = {},
  language = {{ENG}},
  abstract = {{A}mazon {C}ontinental {S}helf ({ACS}) presents highly energetic hydrodynamics, modulated by multiple forcing mechanisms, and significant socio-economic and climate importance. {T}his study characterizes the spatial-temporal variability of hydrodynamics on the {ACS} between 2 degrees {S} and 4 degrees {N} based on in situ data of 6 coastal sea level stations provided by {IBGE}, {BNDO} and {S}i{MC}osta, velocity measurements from 201 drifters of {NOAA} {G}lobal {D}rifter {P}rogram and 3 moorings of the {AMANDES} {III} project, and 127 {CTD} profiles from {AMANDES} and {REVIZEE} projects. {T}he analysis of the coastal sea level shows that the tidal band contributes for 95 % ({S}antana, {A}map{\`a} shelf) to 99 % ({T}uria{\c{c}}u and {R}ibamar, {M}aranhão shelf) of the temporal variability of the sea level. {M}oreover, it shows that characteristics typical of a macrotidal regime occur up to 75 % and 41 % of the time at {T}uria{\c{c}}u and {S}alinópolis, the eastern and central regions of the {ACS}, respectively. {V}elocity time series from drifters and moorings reveal a northwestward flow pattern along the {ACS}, which is associated with wind-driven circulation. {T}he semidiurnal tides play a crucial role in the temporal variability of the cross-shelf velocity component, reaching a maximum percentage importance of 90 % on the central region of the {ACS}. {R}esidual currents (without tides) are more pronounced in the alongshelf component. {T}heir percentage importance increases towards the western shelf, from 68 % (73 %) and 20 % (10 %) in the upper (lower) water column at the eastern shelf, to 95 % (90 %) and 54 % (46 %) in the alongshelf and cross-shelf components, respectively. {T}he wavelet analysis of the residual currents reveals high energy in two distinct period bands between 4 and 20 days and longer than 20 days at all moorings. {T}he first period band is associated with wind modulations, while the second band indicates influence of the {N}orth {B}razil {C}urrent ({NBC}) fluctuations. {T}he time series of {R}ichardson numbers show that the central and western shelves are stable for most of the time (>70 %). {T}he stratification ({N}2) and vertical velocity shear ({S}2) parameters increase toward {MAM}4 (western shelf) associated with the spreading of the {A}mazon {R}iver plume and the increased influence of the {NBC} on the speed and direction of currents in the outer shelf. {T}he {TS} diagrams show the presence of three distinct water masses on the {ACS}: coastal water influenced by river discharge, mixed water, and oceanic water.},
  keywords = {{T}idal and residual currents ; {T}idal and residual sea level ; {R}ichardson number ; {BRESIL} ; {ATLANTIQUE} ; {AMAZONE} {COURS} {D}'{EAU}},
  booktitle = {},
  journal = {{C}ontinental {S}helf {R}esearch},
  volume = {291},
  numero = {},
  pages = {105491 [17 p.]},
  ISSN = {0278-4343},
  year = {2025},
  DOI = {10.1016/j.csr.2025.105491},
  URL = {https://www.documentation.ird.fr/hor/fdi:010093601},
}