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Impact of Intermittent Convection in the Northwestern Mediterranean Sea on Oxygen Content, Nutrients, and the Carbonate System
Author(s) -
Fourrier Marine,
Coppola Laurent,
D’Ortenzio Fabrizio,
Migon Christophe,
Gattuso JeanPierre
Publication year - 2022
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2022jc018615
Subject(s) - water column , oceanography , argo , nutrient , carbonate , mediterranean sea , environmental science , seawater , geology , mixed layer , mediterranean climate , chemistry , ecology , biology , organic chemistry
Using Argo profiling floats, cruises and mooring data, we reconstructed the dissolved oxygen (O 2 ) dynamics in the Gulf of Lion and the Ligurian Sea, with a focus on the intermediate waters. By applying the CANYON‐MED neural network‐based method on the large network of O 2 ‐equipped Argo floats we derived nutrients and carbonate system variables in the Gulf of Lion and the Ligurian Sea at different depths in the water column and derived trends over the 2012–2020 period. In these waters, the O 2 minimum is strongly affected by the intermittent convection process, and the two areas show dissimilar responses to the mixing events. In the absence of deep convection events, the O 2 ‐depleted layer tends to spread vertically and intensify even more so in the Ligurian than in the Gulf of Lion. In both areas, over the 2012–2020 period, nutrients increase overall in deep layers, with a concomitant impact on nutrient molar ratios tending toward an increase in P‐limitation. Acidification estimates derived in different layers of the water column show an overall increase in dissolved inorganic carbon and a concurrent pH decrease. These trends were strongly affected by convection events slowing down the overall acidification trend.