FN Archimer Export Format PT J TI A New Glider-Compatible Optical Sensor for Dissolved Organic Matter Measurements: Test Case from the NW Mediterranean Sea BT AF Cyr, Frédéric Tedetti, Marc Besson, Florent Beguery, Laurent Doglioli, Andrea M. Petrenko, Anne A. Goutx, Madeleine AS 1:1;2:1;3:2;4:2;5:1;6:1;7:1; FF 1:;2:;3:;4:;5:;6:;7:; C1 Aix-Marseille Université, Université de Toulon, Centre National de la Recherche Scientifique/INSU, IRD, Mediterranean Institute of Oceanography, UM 110, Marseille, France ALSEAMAR, Meyreuil, France C2 UNIV AIX MARSEILLE, FRANCE ALSEAMAR, FRANCE SI TOULON SE CNRS IN DOAJ IF 5.247 TC 15 UR https://archimer.ifremer.fr/doc/00654/76597/77747.pdf LA English DT Article CR OSCAHR BO Téthys II DE ;MiniFluo-UV;fluorescence;glider;dissolved organic matter;tryptophan;phenanthrene;Mediterranean Sea AB The MiniFluo-UV is a new glider-compatible optical sensor for measurements of dissolved organic matter (DOM) in natural waters. The working principle, sensor design and challenges faced during the validation phase are reported. The first in situ application of the sensor during three glider deployments in the NW Mediterranean sea (spring, summer, and fall) are also presented. For these campaigns, the two channels of the sensor were adjusted to target Tryptophan-like (excitation/emission wavelengths λEx/λEm: 275/340 nm) and Phenanthrene-like (λEx/λEm: 255/360 nm) fluorescence. These were chosen because they represent fluorophores of interest commonly found in seawater. While Tryptophan (an amino-acid believed to be a by-product of biological activity) is naturally found in the ocean, Phenanthrene (a polycyclic aromatic hydrocarbon) is mainly introduced in the environment by human activities. The addition of these variables to more common physical and biogeochemical glider measurements reveals new features of DOM dynamics in the Mediterranean Sea. For example, the temporal and spatial decoupling between Tryptophan-like and Chl-a fluorescence suggests that the former is not only a marker of phytoplankton activity, but could also give more subtle information on the microbial processes occurring. The identification of a Phenanthrene-like layer just below the pycnocline at all seasons also raises questions on the mechanisms driving its presence in the Mediterranean. Knowing that the role of ocean DOM on atmospheric carbon sequestration is becoming clearer, the high spatio-temporal resolution possible with this new sampling strategy may represents a key step toward our deep understanding of DOM dynamics and its role on the biological pump. PY 2017 SO Frontiers In Marine Science SN 2296-7745 PU Frontiers Media SA VL 4 IS 89 UT 000457690600089 DI 10.3389/fmars.2017.00089 ID 76597 ER EF