FN Archimer Export Format PT J TI Oxygen Saturation Surrounding Deep Water Formation Events in the Labrador Sea From Argo-O-2 Data BT AF WOLF, Mitchell K. HAMME, Roberta C. GILBERT, Denis YASHAYAEV, Igor THIERRY, Virginie AS 1:1;2:1;3:2;4:3;5:4; FF 1:;2:;3:;4:;5:PDG-ODE-LOPS-OH; C1 Univ Victoria, Sch Earth & Ocean Sci, Victoria, BC, Canada. Fisheries & Oceans Canada, Maurice Lamontagne Inst, Mont Joli, PQ, Canada. Fisheries & Oceans Canada, Bedford Inst Oceanog, Dartmouth, NS, Canada. IFREMER, Lab Oceanog Phys & Spatiale, Plouzane, France. C2 UNIV VICTORIA, CANADA MPO INST MAURICE LAMONTAGNE, CANADA MPO BEDFORD INST OCEANOG, CANADA IFREMER, FRANCE SI BREST SE PDG-ODE-LOPS-OH UM LOPS IN WOS Ifremer jusqu'en 2018 copubli-int-hors-europe IF 5.733 TC 25 UR https://archimer.ifremer.fr/doc/00442/55329/56829.pdf https://archimer.ifremer.fr/doc/00442/55329/56830.pdf LA English DT Article DE ;oxygen saturation;convection;Argo;Labrador Sea;deep water formation AB Deep water formation supplies oxygen-rich water to the deep sea, spreading throughout the ocean by means of the global thermohaline circulation. Models suggest that dissolved gases in newly formed deep water do not come to equilibrium with the atmosphere. However, direct measurements during wintertime convection are scarce, and the controls over the extent of these disequilibria are poorly quantified. Here we show that, when convection reached deeper than 800 m, oxygen in the Labrador Sea was consistently undersaturated at -6.1% to -7.6% at the end of convection. Deeper convection resulted in greater undersaturation, while convection ending later in the year resulted in values closer to equilibrium, from which we produce a predictive relationship. We use dissolved oxygen data from six profiling Argo floats in the Labrador Sea between 2003 and 2016, allowing direct observations of wintertime convection. Three of the six optode oxygen sensors displayed substantial average in situ drift of -3.03 mu mol O-2 kg(-1)yr(-1) (-0.94% O-2 yr(-1)), which we corrected to stable deepwater oxygen values from repeat ship surveys. Observations of low oxygen intrusions during restratification and a simple mixing calculation demonstrate that lateral processes act to lower the oxygen inventory of the central Labrador Sea. This suggests that the Labrador Sea is a net sink for atmospheric oxygen, but uncertainties in parameterizing gas exchange limit our ability to quantify the net uptake. Our results constrain the oxygen concentration of newly formed Labrador Sea Water and allow more precise estimates of oxygen utilization and nutrient regeneration in this water mass. PY 2018 PD APR SO Global Biogeochemical Cycles SN 0886-6236 PU Amer Geophysical Union VL 32 IS 4 UT 000431991800007 BP 635 EP 653 DI 10.1002/2017GB005829 ID 55329 ER EF