Drivers of fluorescent dissolved organic matter in the global epipelagic ocean

Catalá, Teresa S. ... et al.-- 19 pages, 7 figures, 1 table, supporting information https://dx.doi.org/10.1002/lno.10281Fluorescent dissolved organic matter (FDOM) in open surface waters ( 70%) than for the amino acid-like components ( 200 m), the relationships of C1 and C2 with AOU indicate a higher C1/AOU and C2/AOU ratios of the humic-like substances in the dark ocean than in the surface ocean where a net effect of photobleaching is also detected. C3 (tryptophan-like) and C4 (tyrosine-like) variability was mostly dictated by salinity (S), by means of positive non-linear relationships, suggesting a primary physical control of their distributions at the global surface ocean scale that could be related to the changing evaporation-precipitation regime. Remarkably, bacterial biomass (BB) only contributed to explain a minor part of the variability of C1 and C4T.S.C acknowledges funding through a predoctoral fellowship (reference AP2009-2138) from the Ministerio de Educación, Cultura y Deporte. [...] J. Otero was supported by “Junta para la Ampliación de Estudios” Fellowship (JAE-Doc program 2011) from the CSIC and ESF. M. Nieto-Cid was funded by the EU FP/-IOF project FeBOL-220172 and the CSIC Program “Junta para la Ampliación de Estudios” co-financed by the ESF. B. Horstkotte was supported by JAE 2010 Postdoctoral fellowship from the CSIC. This study was financed by the Malaspina 2010 circumnavigation expedition (grant number CSD2008–00077)Peer Reviewe