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Toyama, Katsuya; Rodgers, Keith B.; Blanke, Bruno; Iudicone, Daniele; Ishii, Masao; Aumont, Olivier; Sarmiento, Jorge L.. |
We evaluate the output from a widely used ocean carbon cycle model to identify the subduction and obduction (re-emergence) rates of anthropogenic carbon (Cant) for climatological conditions during the World Ocean Circulation Experiment (WOCE) era in 1995 using a new set of Lagrangian diagnostic tools. The principal scientific value of the Lagrangian diagnostics is in providing a new means to connect Cant re-emergence pathways to the relatively rapid renewal timescales of mode waters through the overturning circulation. Our main finding is that for this model with 2.04 PgC/yr of uptake of Cant via gas exchange, the subduction and obduction rates across the base of the mixed layer (MLbase) are 4.96 PgC/yr and 4.50 PgC/yr, respectively, which are twice as... |
Tipo: Text |
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Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00395/50610/51323.pdf |
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Rodgers, Keith B.; Key, Robert M.; Gnanadesikan, Anand; Sarmiento, Jorge L.; Aumont, Olivier; Bopp, Laurent; Doney, Scott C.; Dunne, John P.; Glover, David M.; Ishida, Akio; Ishii, Masao; Jacobson, Andrew R.; Lo Monaco, Claire; Maier-reimer, Ernst; Mercier, Herle; Metzl, Nicolas; Perez, Fiz F.; Rios, Aida F.; Wanninkhof, Rik; Wetzel, Patrick; Winn, Christopher D.; Yamanaka, Yasuhiro. |
Here we use observations and ocean models to identify mechanisms driving large seasonal to interannual variations in dissolved inorganic carbon (DIC) and dissolved oxygen (O-2) in the upper ocean. We begin with observations linking variations in upper ocean DIC and O-2 inventories with changes in the physical state of the ocean. Models are subsequently used to address the extent to which the relationships derived from short-timescale (6 months to 2 years) repeat measurements are representative of variations over larger spatial and temporal scales. The main new result is that convergence and divergence (column stretching) attributed to baroclinic Rossby waves can make a first-order contribution to DIC and O-2 variability in the upper ocean. This results in... |
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Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11107/7415.pdf |
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Majkut, Joseph D.; Carter, Brendan R.; Froelicher, Thomas L.; Dufour, Carolina O.; Rodgers, Keith B.; Sarmiento, Jorge L.. |
The Southern Ocean is critically important to the oceanic uptake of anthropogenic CO2. Up to half of the excess CO2 currently in the ocean entered through the Southern Ocean. That uptake helps to maintain the global carbon balance and buffers transient climate change from fossil fuel emissions. However, the future evolution of the uptake is uncertain, because our understanding of the dynamics that govern the Southern Ocean CO2 uptake is incomplete. Sparse observations and incomplete model formulations limit our ability to constrain the monthly and annual uptake, interannual variability and long-term trends. Float-based sampling of ocean biogeochemistry provides an opportunity for transforming our understanding of the Southern Ocean CO2 flux. In this work,... |
Tipo: Text |
Palavras-chave: Carbon; Southern Ocean; Observational system simulation experiment. |
Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40115/38747.pdf |
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Ishii, Masao; Rodgers, Keith B.; Inoue, Hisayuki Y.; Toyama, Katsuya; Sasano, Daisuke; Kosugi, Naohiro; Ono, Hisashi; Enyo, Kazutaka; Nakano, Toshiya; Iudicone, Daniele; Blanke, Bruno; Aumont, Olivier; Feely, Richard A.. |
Identifying ocean acidification and its controlling mechanisms is an important priority within the broader question of understanding how sustained anthropogenic CO2 emissions are harming the health of the ocean. Through extensive analysis of observational data products for ocean inorganic carbon, here we quantify the rate at which acidification is proceeding in the western tropical Pacific Warm Pool, revealing ‐0.0013 ±0.0001 yr‐1 for pH and ‐0.0083±0.0007 yr‐1 for the saturation index of aragonite for the years 1985‐2016. However, the mean rate of total dissolved inorganic carbon increase (+0.81 ±0.06 μmol kg‐1 yr‐1) sustaining acidification was ~20% slower than what would be expected if it were simply controlled by the rate of atmospheric CO2 increase... |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00641/75337/76003.pdf |
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