FN Archimer Export Format PT J TI Deep Chlorophyll Maxima in the global ocean: occurrences, drivers and characteristics BT AF Cornec, M. Claustre, H. Mignot, A. Guidi, L. Lacour, L. Poteau, A. D'Ortenzio, F. Gentili, B. Schmechtig, C. AS 1:1;2:1;3:2;4:1;5:3,4;6:1;7:1;8:1;9:1; FF 1:;2:;3:;4:;5:;6:;7:;8:;9:; C1 CNRS & Sorbonne Université Laboratoire d'Océanographie de Villefranche LOV Villefranche‐sur‐Mer ,France Mercator Océan International Ramonville‐Saint‐Agne, France Takuvik Joint International Laboratory, Laval University (Canada) - CNRS (France), Département de biologie et Québec-Océan, Université Laval, Québec, Canada Takuvik Joint International Laboratory, Laval University (Canada) - CNRS (France), Département de biologie et Québec-Océan, Université Laval, Québec, Canada C2 CNRS, FRANCE MERCATOR OCEAN, FRANCE UNIV LAVAL, CANADA CNRS, FRANCE IF 6.5 TC 64 UR https://archimer.ifremer.fr/doc/00685/79669/82442.pdf https://archimer.ifremer.fr/doc/00685/79669/82443.docx LA English DT Article DE ;BGC‐Argo floats;deep chlorophyll maximum;irradiance;nitracline;open ocean;particle backscattering;stratification AB Stratified oceanic systems are characterized by the presence of a so‐called Deep Chlorophyll a Maximum (DCM) not detectable by ocean color satellites. A DCM can either be a phytoplankton (carbon) biomass maximum (Deep Biomass Maximum, DBM), or the consequence of photoacclimation processes (Deep photoAcclimation Maximum, DAM) resulting in the increase of chlorophyll a per phytoplankton carbon. Even though these DCM (further qualified as either DBMs or DAMs) have long been studied, no global‐scale assessment has yet been undertaken and large knowledge gaps still remain in relation to the environmental drivers responsible for their formation and maintenance. In order to investigate their spatial and temporal variability in the open ocean, we use a global dataset acquired by more than 500 Biogeochemical‐Argo floats given that DCMs can be detected from the comparative vertical distribution of chlorophyll a concentrations and particulate backscattering coefficients. Our findings show that the seasonal dynamics of the DCMs are clearly region‐dependent. High‐latitude environments are characterized by a low occurrence of intense DBMs, restricted to summer. Meanwhile, oligotrophic regions host permanent DAMs, occasionally replaced by DBMs in summer, while subequatorial waters are characterized by permanent DBMs benefiting from favorable conditions in terms of both light and nutrients. Overall, the appearance and depth of DCMs are primarily driven by light attenuation in the upper layer. Our present assessment of DCM occurrence and of environmental conditions prevailing in their development lay the basis for a better understanding and quantification of their role in carbon budgets (primary production and export). PY 2021 PD APR SO Global Biogeochemical Cycles SN 0886-6236 PU American Geophysical Union (AGU) VL 35 IS 4 UT 000644999800011 DI 10.1029/2020GB006759 ID 79669 ER EF