A high-resolution time-depth view of dimethylsulphide cycling in the surface sea

Abstract

13 pages, 7 figures, tables, supporting information https://dx.doi.org/10.1038/srep32325 ; Emission of the trace gas dimethylsulphide (DMS) from the ocean influences the chemical and optical properties of the atmosphere, and the olfactory landscape for foraging marine birds, turtles and mammals. DMS concentration has been seen to vary across seasons and latitudes with plankton taxonomy and activity, and following the seascape of ocean's physics. However, whether and how does it vary at the time scales of meteorology and day-night cycles is largely unknown. Here we used high-resolution measurements over time and depth within coherent water patches in the open sea to show that DMS concentration responded rapidly but resiliently to mesoscale meteorological perturbation. Further, it varied over diel cycles in conjunction with rhythmic photobiological indicators in phytoplankton. Combining data and modelling, we show that sunlight switches and tunes the balance between net biological production and abiotic losses. This is an outstanding example of how biological diel rhythms affect biogeochemical processes ; This research has been funded by the successive Spanish Ministries of Science through projects SUMMER (CTM2008-03309/MAR) and PEGASO (CTM2012-37615), and through a PhD scholarship to S.-J.R. M.G. acknowledges the receipt of a Beatriu de Pinós post-doctoral fellowship funded by the Generalitat de Catalunya. Support was also provided to E.S.S. by the U.S. National Science Foundation (grants 0851472 and 1143709). O.N.R. acknowledges financial support from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007–2013/ under REA grant agreement n° 624170 as well as the AMICO-BIO project (12-MCGOT-GMES-1-CVS-047/MEDDE/CNRS-INSU). G.L.P. acknowledges an international mobility scholarship from CONICET (Argentina). A.S.M. acknowledges support from the Ministry of Earth Sciences, Government of India ; Peer Reviewed