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Light‐driven cycling of dimethylsulfide (DMS) in the Sargasso Sea: Closing the loop
Author(s) -
Toole Dierdre A.,
Siegel David A.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl019581
Subject(s) - phytoplankton , environmental science , dimethylsulfoniopropionate , oceanography , eutrophication , cycling , biogeochemical cycle , sargasso sea , forcing (mathematics) , microbial loop , climatology , environmental chemistry , nutrient , ecology , chemistry , biology , geology , history , archaeology
The factors driving dimethylsulfide (DMS) cycling in oligotrophic environments are isolated using a time‐series of DMS sampled in the Sargasso Sea. The observed distribution of DMS is inconsistent with bottom‐up processes related to phytoplankton production, biomass, or community structure changes. DMS concentrations and estimates of net biological community production are most highly correlated with physical and optical properties, with the dose of ultraviolet radiation (UVR) accounting for 77% of the variability in mixed layer DMS concentrations. Physiological stresses associated with shallow mixed layers and high UVR are the first order determinant of biological production of DMS, indicating that DMS cycling in open‐ocean regions is fundamentally different than in eutrophic regions where phytoplankton blooms provide the conditions for elevated DMS concentrations. The stress regime presented here effectively closes the DMS‐climate feedback loop for open‐ocean environments. This response may also provide a climatic role for phytoplanktonic processes in response to anthropogenic forcing.