@article{fdi:010095564,
  title = {{I}mpact of internal tides on chlorophyll a distribution and primary production off the {A}mazon shelf from glider measurements and satellite observations},
  author = {{M}'{H}amdi, {A}. and {K}och {L}arrouy, {A}riane and {C}osta da {S}ilva, {A}. and {D}adou, {I}. and de {M}acedo, {C}. and {B}osse, {A}. and {V}antrepotte, {V}incent and {A}guedjou, {H}. and {T}ran, {T}. {K}. and {T}estor, {P}. and {M}ortier, {L}. and {B}ertrand, {A}rnaud and {M}endes de {C}astro {M}elo, {P}. and {L}ee, {J}. {M}. and {R}ollnic, {M}. and {A}raujo, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he ocean region off the {A}mazon shelf including the shelf break presents a hotspot for internal tide ({IT}) generation, yet its impact on phytoplankton distribution remains poorly understood. {W}hile previous studies have extensively examined the physical characteristics and dynamics of {IT}s, their biological implications - particularly in nutrient-limited environments - remain underexplored. {T}o address this question, we analyzed a 26 d glider mission deployed over {S}eptember-{O}ctober 2021 sampling hydrographic and optical properties (chlorophyll a) at high resolution along an {IT} pathway as well as satellite chlorophyll a and altimetry data to assess mesoscale interactions. {C}hlorophyll a dynamics were analyzed under varying {IT} intensities, comparing strong ({HT}) and weak ({LT}) internal tide conditions. {R}esults reveal that {IT}s drive vertical displacements of the deep chlorophyll maximum ({DCM}) from 15 to 45 m, accompanied by 50 % expansion in its thickness during {HT} events. {T}his expansion is observed with a dilution of the chlorophyll a maximum concentration within the {DCM} depth. {W}hile direct turbulence measurements were not collected, the observed vertical redistribution of chlorophyll a is indicative of tidally driven cross-isopycnal exchanges, the only physical mechanism explaining the transfer of biomass above and below the {DCM}. {A}t the surface, turbulent fluxes provide 38 % of the chlorophyll a input, while the remainder is supplied by in situ biological activity. {N}otably, total chlorophyll a in the water column increases by 14 %-29 % during high internal tide phases, indicating a net enhancement of primary productivity driven by the combined effects of vertical mixing and stimulated surface-layer biological activity. {T}hese findings indicate that internal tides can be an important driver of chlorophyll a distribution and short-term biological variability in our study region. {B}y reshaping the vertical chlorophyll a profile through vertical mixing, active internal tides influence primary productivity and may contribute to carbon cycling, particularly in oligotrophic oceanic environments where both a deep chlorophyll maximum and strong internal tides are present.},
  keywords = {{ATLANTIQUE} ; {BRESIL} ; {AMAZONE}},
  booktitle = {},
  journal = {{O}cean {S}cience},
  volume = {21},
  numero = {6},
  pages = {2873--2894},
  ISSN = {1812-0784},
  year = {2025},
  DOI = {10.5194/os-21-2873-2025},
  URL = {https://www.documentation.ird.fr/hor/fdi:010095564},
}