TY - JOUR T1 - Role of Iron in the Marquesas Island Mass Effect A1 - Raapoto,Hirohiti A1 - Martinez,Elodie A1 - Petrenko,Anne A1 - Doglioli,Andrea A1 - Gorgues,Thomas A1 - Sauzède,Raphaëlle A1 - Maamaatuaiahutapu,Keitapu A1 - Maes,Christophe A1 - Menkes,Christophe A1 - Lefèvre,Jérôme AD - UPF, IRD, ILM, Ifremer, Écosystèmes Insulaires Océaniens Tahiti ,French Polynesia AD - Université Brest, Ifremer, CNRS, IRD, Laboratoire d'Océanographie Physique et Spatiale, IUEM Brest ,France AD - Aix‐Marseille University, Université de Toulon, CNRS, IRD, OSU PYTHEAS, Mediterranean Institute of Oceanography MIO, UM 110, 13288 Marseille ,France AD - Sorbonne Université, CNRS, Institut de la Mer de Villefranche, Laboratoire d'Océanographie de Villefranche Villefranche‐sur‐Mer ,France AD - Université de la Polynésie française, GePaSud Laboratory Tahiti ,French Polynesia AD - IRD/Sorbonne Universités Nouméa, New Caledonia UR - https://archimer.ifremer.fr/doc/00592/70397/ DO - 10.1029/2019JC015275 N2 - A remarkable chlorophyll‐a concentration (Chl, a proxy of phytoplankton biomass) plume can be noticed on remotely sensed ocean color observations at the boundary separating the equatorial mesotrophic from the subtropical oligotrophic waters in the central South Pacific Ocean. This prominent biological feature is known as the island mass effect of the Marquesas archipelago. Waters surrounding these islands present high macronutrient concentrations but an iron depletion. In this study, the origin of Chl enhancement is investigated using a modeling approach. Four simulations based on identical physical and biogeochemical forcings but with different iron sources are conducted and analyzed. Only simulations considering an iron input from the island sediments present similar patterns (despite being too weak) of vertical and horizontal Chl distributions as compared to biogeochemical‐Argo profiling float and satellite observations. In addition, simulations with no other iron input than the boundary forcings reveal the relative importance of remote processes in modulating the seasonal pattern of Chl around the archipelago through horizontal advection of nutrient‐rich waters from the equator toward the archipelago and vertical mixing uplifting deep nutrient‐rich waters toward the upper lit layer. Y1 - 2019/11 PB - American Geophysical Union (AGU) JF - Journal Of Geophysical Research-oceans SN - 2169-9275 VL - 124 IS - 11 SP - 7781 EP - 7796 ID - 70397 ER -