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Key Uncertainties in the Recent Air‐Sea Flux of CO2 5
Woolf, D.k.; Shutler, J.d.; Goddijn‐murphy, L.; Watson, A.j.; Chapron, Bertrand; Nightingale, P.d.; Donlon, C.j.; Piskozub, J.; Yelland, M.j.; Ashton, Ian; Holding, T.; Schuster, U.; Girard-ardhuin, Fanny; Grouazel, Antoine; Piolle, Jean-francois; Warren, M.; Wrobel‐niedzwiecka, I.; Land, P.e.; Torres, R.; Prytherch, J.; Moat, B.; Hanafin, J.; Ardhuin, Fabrice; Paul, Frederic.
The contemporary air‐sea flux of CO2 is investigated by the use of an air‐sea flux equation, with particular attention to the uncertainties in global values and their origin with respect to that equation. In particular, uncertainties deriving from the transfer velocity and from sparse upper ocean sampling are investigated. Eight formulations of air‐sea gas transfer velocity are used to evaluate the combined standard uncertainty resulting from several sources of error. Depending on expert opinion, a standard uncertainty in transfer velocity of either ~5% or ~10% can be argued and that will contribute a proportional error in air‐sea flux. The limited sampling of upper ocean fCO2 is readily apparent in the Surface Ocean CO2 Atlas (SOCAT) databases. The effect...
Tipo: Text Palavras-chave: Carbon dioxide; Air-sea flux; Uncertainty; Transfer velocity; Sampling.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00513/62450/66754.pdf
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Optimum satellite remote sensing of the marine carbonate system using empirical algorithms in the global ocean, the Greater Caribbean, the Amazon Plume and the Bay of Bengal 5
Land, Peter E.; Findlay, Helen S.; Shutler, Jamie D.; Ashton, Ian; Holding, Thomas; Grouazel, Antoine; Ardhuin, Fanny; Reul, Nicolas; Piolle, Jean-francois; Chapron, Bertrand; Quilfen, Yves; Bellerby, Richard G.j.; Bhadury, Punyasloke; Salisbury, Joseph; Vandemark, Douglas; Sabia, Roberto.
Improving our ability to monitor ocean carbonate chemistry has become a priority as the ocean continues to absorb carbon dioxide from the atmosphere. This long-term uptake is reducing the ocean pH; a process commonly known as ocean acidification. The use of satellite Earth Observation has not yet been thoroughly explored as an option for routinely observing surface ocean carbonate chemistry, although its potential has been highlighted. We demonstrate the suitability of using empirical algorithms to calculate total alkalinity (AT) and total dissolved inorganic carbon (CT), assessing the relative performance of satellite, interpolated in situ, and climatology datasets in reproducing the wider spatial patterns of these two variables. Both AT and CT in situ...
Tipo: Text Palavras-chave: Carbonate chemistry; Earth observation; Ocean acidification; Total alkalinity; Dissolved inorganic carbon; SMOS; Aquarius; CORA; HadGEM2-ES.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00591/70267/68368.pdf
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Refined sea state analysis from an array of four identical directional buoys deployed off the Northern Cornish coast (UK) 5
Saulnier, Jean Baptiste; Maisondieu, Christophe; Ashton, Ian; Smith, George H..
This paper presents an analysis of sea states carried out from extended wave measurements realized near the Wave Hub wave energy test facility in Cornwall (UK). The space directional information is derived from the spectro-directional processing of time-domain data provided by an array of four independent SEAWATCH Mini II displacement buoys separated by an approximate average distance of 500 m. It is observed that, even though the size of the array is small compared to the local wave trains' length, the estimation of the directional spectra - using maximum entropy and likelihood methods - may sometimes exhibit certain space variability over the array. It was also observed that the tidal currents variations produced a significant influence upon the wave...
Tipo: Text Palavras-chave: Directional wave spectrum; Directional buoys; Buoys array; Maximum entropy method; Maximum Likelihood Method; Sea state; Wave system; Spectro-directional partitioning; Wave stationarity/homogeneity; Wave/tide interactions.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00098/20922/18739.pdf
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Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean carbon inventory 5
Watson, Andrew J.; Schuster, Ute; Shutler, Jamie D.; Holding, Thomas; Ashton, Ian; Landschuetzer, Peter; Woolf, David K.; Goddijn-murphy, Lonneke.
The ocean is a sink for similar to 25% of the atmospheric CO2 emitted by human activities, an amount in excess of 2 petagrams of carbon per year (PgCyr(-1)). Time-resolved estimates of global ocean-atmosphere CO2 flux provide an important constraint on the global carbon budget. However, previous estimates of this flux, derived from surface ocean CO2 concentrations, have not corrected the data for temperature gradients between the surface and sampling at a few meters depth, or for the effect of the cool ocean surface skin. Here we calculate a time history of ocean-atmosphere CO2 fluxes from 1992 to 2018, corrected for these effects. These increase the calculated net flux into the oceans by 0.8-0.9 PgC yr(-1), at times doubling uncorrected values. We...
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Ano: 2020 URL: https://archimer.ifremer.fr/doc/00676/78826/81135.pdf
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Satellites will address critical science priorities for quantifying ocean carbon 5
Shutler, Jamie D; Wanninkhof, Rik; Nightingale, Philip D; Woolf, David K; Bakker, Dorothee Ce; Watson, Andy; Ashton, Ian; Holding, Thomas; Chapron, Bertrand; Quilfen, Yves; Fairall, Chris; Schuster, Ute; Nakajima, Masakatsu; Donlon, Craig J.
The ability to routinely quantify global carbon dioxide (CO2) absorption by the oceans has become crucial: it provides a powerful constraint for establishing global and regional carbon (C) budgets, and enables identification of the ecological impacts and risks of this uptake on the marine environment. Advances in understanding, technology, and international coordination have made it possible to measure CO2 absorption by the oceans to a greater degree of accuracy than is possible in terrestrial landscapes. These advances, combined with new satellite‐based Earth observation capabilities, increasing public availability of data, and cloud computing, provide important opportunities for addressing critical knowledge gaps. Furthermore, Earth observation in...
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Ano: 2020 URL: https://archimer.ifremer.fr/doc/00590/70256/68305.pdf
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The FluxEngine air–sea gas flux toolbox: simplified interface and extensions for in situ analyses and multiple sparingly soluble gases 5
Holding, Thomas; Ashton, Ian; Shutler, Jamie D.; Land, Peter E.; Nightingale, Philip D.; Rees, Andrew P.; Brown, Ian; Piolle, Jean-francois; Kock, Annette; Bange, Hermann W.; Woolf, David K.; Goddijn-murphy, Lonneke; Pereira, Ryan; Paul, Frederic; Girard-ardhuin, Fanny; Chapron, Bertrand; Rehder, Gregor; Ardhuin, Fabrice; Donlon, Craig J..
The flow (flux) of climate-critical gases, such as carbon dioxide (CO2), between the ocean and the atmosphere is a fundamental component of our climate and an important driver of the biogeochemical systems within the oceans. Therefore, the accurate calculation of these air–sea gas fluxes is critical if we are to monitor the oceans and assess the impact that these gases are having on Earth's climate and ecosystems. FluxEngine is an open-source software toolbox that allows users to easily perform calculations of air–sea gas fluxes from model, in situ, and Earth observation data. The original development and verification of the toolbox was described in a previous publication. The toolbox has now been considerably updated to allow for its use as a Python...
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Ano: 2019 URL: https://archimer.ifremer.fr/doc/00598/70983/69247.pdf
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Winter weather controls net influx of atmospheric CO2 on the northwest European shelf 5
Kitidis, Vassilis; Shutler, Jamie D.; Ashton, Ian; Warren, Mark; Brown, Ian; Findlay, Helen; Hartman, Sue E.; Sanders, Richard; Humphreys, Matthew; Kivimae, Caroline; Greenwood, Naomi; Hull, Tom; Pearce, David; Mcgrath, Triona; Stewart, Brian M.; Walsham, Pamela; Mcgovern, Evin; Bozec, Yann; Gac, Jean-philippe; Van Heuven, Steven M. A. C.; Hoppema, Mario; Schuster, Ute; Johannessen, Truls; Omar, Abdirahman; Lauvset, Siv K.; Skjelvan, Ingunn; Olsen, Are; Steinhoff, Tobias; Koertzinger, Arne; Becker, Meike; Lefevre, Nathalie; Diverres, Denis; Gkritzalis, Thanos; Cattrijsse, Andre; Petersen, Wilhelm; Voynova, Yoana G.; Chapron, Bertrand; Grouazel, Antoine; Land, Peter E.; Sharples, Jonathan; Nightingale, Philip D..
Shelf seas play an important role in the global carbon cycle, absorbing atmospheric carbon dioxide (CO2) and exporting carbon (C) to the open ocean and sediments. The magnitude of these processes is poorly constrained, because observations are typically interpolated over multiple years. Here, we used 298500 observations of CO2 fugacity (fCO(2)) from a single year (2015), to estimate the net influx of atmospheric CO2 as 26.2 +/- 4.7 Tg C yr(-1) over the open NW European shelf. CO2 influx from the atmosphere was dominated by influx during winter as a consequence of high winds, despite a smaller, thermally-driven, air-sea fCO(2) gradient compared to the larger, biologically-driven summer gradient. In order to understand this climate regulation service, we...
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Ano: 2019 URL: https://archimer.ifremer.fr/doc/00607/71869/70566.pdf
Registros recuperados: 7
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