Premium
Intense oceanic uptake of oxygen during 2014–2015 winter convection in the Labrador Sea
Author(s) -
Koelling Jannes,
Wallace Douglas W. R.,
Send Uwe,
Karstensen Johannes
Publication year - 2017
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 - 10.1002/2017gl073933
Subject(s) - mixed layer , oxygen , convection , forcing (mathematics) , atmospheric sciences , mooring , environmental science , geology , deep convection , climatology , oceanography , chemistry , meteorology , physics , organic chemistry
Abstract Measurements of near‐surface oxygen (O 2 ) concentrations and mixed layer depth from the K1 mooring in the central Labrador Sea are used to calculate the change in column‐integrated (0–1700 m) O 2 content over the deep convection winter 2014/2015. During the mixed layer deepening period, November 2014 to April 2015, the oxygen content increased by 24.3 ± 3.4 mol m −2 , 40% higher than previous results from winters with weaker convection. By estimating the contribution of respiration and lateral transport on the oxygen budget, the cumulative air‐sea gas exchange is derived. The O 2 uptake of 29.1 ± 3.8 mol m −2 , driven by persistent undersaturation (≥5%) and strong atmospheric forcing, is substantially higher than predicted by standard (nonbubble) gas exchange parameterizations, whereas most bubble‐resolving parameterizations predict higher uptake, comparable to our results. Generally large but varying mixed layer depths and strong heat and momentum fluxes make the Labrador Sea an ideal test bed for process studies aimed at improving gas exchange parameterizations.