Seasonal and interannual variability of ocean color and composition of phytoplankton communities in the North Atlantic, Equatorial Pacific and South Pacific

• Published in: Deep Sea Research Part II: Topical Studies in Oceanography
• Main Authors: Dandonneau, Yves, Deschamps, Pierre-Yves, Nicolas, Jean-Marc, Loisel, Hubert, Blanchot, Jean, Montel, Yves, Thieuleux, Francois, Bécu, Guislain
• Other Authors: Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), UR CYROCO (IRD/ARVAM), INSU/CNES/IRD, GeP&SIMBAD
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: chlorophyll; global; satellite; variability; seasonal; interannual; 92.20.Sg; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Austral; Pacific; Indian; North Atlantic
• Online Access: https://hal.science/hal-00155032; https://hal.science/hal-00155032/document; https://hal.science/hal-00155032/file/yd_swfs.pdf; https://doi.org/10.1016/j.dsr2.2003.07.018

International audience Monthly averaged level-3 SeaWiFS chlorophyll concentration data from 1998 to 2001 are globally analyzed using Fourier's analysis to determine the main patterns of temporal variability in all parts of the world ocean. In most regions, seasonal variability dominates over interannual variability, and the timing of the yearly bloom can generally be explained by the local cycle of solar energy. The studied period was influenced by the late consequences of the very strong El Niño of 1997-98. After this major event, the recovery to normal conditions followed different patterns at different locations. Right at the equator, chlorophyll concentration was abnormally high in 1998, and then decreased, while aside from the equator, it was low in 1998, and increased later when equatorial upwelled waters spread poleward. This resulted in opposed linear trends with time in these two zones. Other noticeable examples of interannual variability in the open ocean are blooms of Trichodesmium that develop episodically in austral summer in the south-western tropical Pacific, or abnormally high chlorophyll concentration at 5°S in the Indian Ocean after a strong Madden-Julian oscillation. Field data collected quarterly from November 1999 to August 2001, owing to surface sampling from a ship of opportunity, are presented to document the succession of phytoplankton populations that underlie the seasonal cycles of chlorophyll abundance. Indeed, the composition of the phytoplankton conditions the efficiency of the biological carbon pump in the various oceanic provinces. We focus on the north Atlantic, Caribbean Sea, Gulf of Panama, equatorial Pacific, south Pacific subtropical gyre, and south-western tropical Pacific where these field data have been collected,. These data are quantitative inventories of pigments (measured by HPLC and spectrofluorometry), and picoplankton abundance (Prochlorococcus, Synechococcus, Picoeucaryotes and bacteria). There is a contrast between temperate waters where nanoplankton (as ...