Relationships between the deep chlorophyll maximum and hydrographic characteristics across the Atlantic, Indian and Pacific oceansEstrada, Marta (Avtor) Latasa, Mikel (Avtor) Cabello, Ana Maria (Avtor) de la Fuente, Patricia (Avtor) Guallar, Carles (Avtor) Mozetič, Patricija (Avtor) Malaspina 2010chlorophyll anitraclinedeep chlorophyll maximumphytoplankton size fractionationAtlantic OceanPacific OceanIndian Oceanhydrobiologymarine biologyThe Malaspina-2010 circumnavigation expedition on board R/V Hesperides surveyed tropical and subtropical regions of the Atlantic, Indian and Pacific oceans between December 2010 and July 2011. This article examines the relationships between the distribution of chlorophyll a (Chl a), major inorganic nutrients and other hydrographic variables. A deep chlorophyll maximum (DCM) was found at most stations between 60 and 150 m depth; it occurred close to the level of 1% surface photosynthetically active radiation and was associated with the nitracline. There was a negative relationship between total Chl a at surface and the DCM depth, and between Chl a concentration at the DCM and DCM depth. In terms of Chl a concentration, picophytoplankton was the dominant size class at all sampled light intensities (surface, 20% of surface PAR and PAR at DCM), oceans and geoclimatic zones, except at some stations influenced by upwellings or divergences. Within the Chl a concentration ranges found in this study, the proportion of picophytoplankton increased with total Chl a, in contrast with some previous findings. Vertically integrated Chl a was positively correlated with surface Chl a, with similar slopes for the whole data set and for the different oceans and zones. In turn, surface Chl a and sea surface temperature showed a negative correlation for the Indian Ocean and the subtropical zone, a positive correlation for the Atlantic, and non-significant relationships for the remaining oceans and zones.20242025-04-04 10:42:22Neznano21830UDK: 574ISSN pri članku: 1886-8134DOI: 10.3989/scimar.05519.092COBISS_ID: 228680195sl