scholarly journals Sensitivity of the regional ocean acidification and carbonate system in Puget Sound to ocean and freshwater inputs

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Laura Bianucci ◽  
Wen Long ◽  
Tarang Khangaonkar ◽  
Gregory Pelletier ◽  
Anise Ahmed ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Puget Sound ◽  
Ocean Model ◽  
Total Alkalinity ◽  
Salish Sea ◽  
Carbonate System ◽  
Saturation State ◽  
Juan De Fuca ◽  
Freshwater Inputs

While ocean acidification was first investigated as a global phenomenon, coastal acidification has received significant attention in recent years, as its impacts have been felt by different socio-economic sectors (e.g., high mortality of shellfish larvae in aquaculture farms). As a region that connects land and ocean, the Salish Sea (consisting of Puget Sound and the Straits of Juan de Fuca and Georgia) receives inputs from many different sources (rivers, wastewater treatment plants, industrial waste treatment facilities, etc.), making these coastal waters vulnerable to acidification. Moreover, the lowering of pH in the Northeast Pacific Ocean also affects the Salish Sea, as more acidic waters get transported into the bottom waters of the straits and estuaries. Here, we use a numerical ocean model of the Salish Sea to improve our understanding of the carbonate system in Puget Sound; in particular, we studied the sensitivity of carbonate variables (e.g., dissolved inorganic carbon, total alkalinity, pH, saturation state of aragonite) to ocean and freshwater inputs. The model is an updated version of our FVCOM-ICM framework, with new carbonate-system and sediment modules. Sensitivity experiments altering concentrations at the open boundaries and freshwater sources indicate that not only ocean conditions entering the Strait of Juan de Fuca, but also the dilution of carbonate variables by freshwater sources, are key drivers of the carbonate system in Puget Sound.

scholarly journals CO<sub>2</sub> perturbation experiments: similarities and differences between dissolved inorganic carbon and total alkalinity manipulations

2009 ◽  
Vol 6 (10) ◽  
pp. 2145-2153 ◽  
Author(s):  
K. G. Schulz ◽  
J. Barcelos e Ramos ◽  
R. E. Zeebe ◽  
U. Riebesell
Keyword(s):  
Ocean Acidification ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Calcium Carbonate Precipitation ◽  
Carbonate Chemistry ◽  
Carbonate System ◽  
Experimental Conditions ◽  
Saturation State ◽  
Basic Approaches

Abstract. Increasing atmospheric carbon dioxide (CO2) through human activities and invasion of anthropogenic CO2 into the surface ocean alters the seawater carbonate chemistry, increasing CO2 and bicarbonate (HCO3−) at the expense of carbonate ion (CO32−) concentrations. This redistribution in the dissolved inorganic carbon (DIC) pool decreases pH and carbonate saturation state (Ω). Several components of the carbonate system are considered potential key variables influencing for instance calcium carbonate precipitation in marine calcifiers such as coccolithophores, foraminifera, corals, mollusks and echinoderms. Unravelling the sensitivities of marine organisms and ecosystems to CO2 induced ocean acidification (OA) requires well-controlled experimental setups and accurate carbonate system manipulations. Here we describe and analyse the chemical changes involved in the two basic approaches for carbonate chemistry manipulation, i.e. changing DIC at constant total alkalinity (TA) and changing TA at constant DIC. Furthermore, we briefly introduce several methods to experimentally manipulate DIC and TA. Finally, we examine responses obtained with both approaches using published results for the coccolithophore Emiliania huxleyi. We conclude that under most experimental conditions in the context of ocean acidification DIC and TA manipulations yield similar changes in all parameters of the carbonate system, which implies direct comparability of data obtained with the two basic approaches for CO2 perturbation.

scholarly journals OceanSODA-ETHZ: A global gridded data set of the surface ocean carbonate system for seasonal to decadal studies of ocean acidification

2020 ◽  
Author(s):  
Luke Gregor ◽  
Nicolas Gruber
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Total Error ◽  
Total Alkalinity ◽  
Global Ocean ◽  
Carbonate System ◽  
Data Set ◽  
Saturation State ◽  
Mean Squared Errors ◽  
Surface Ocean

Abstract. Ocean acidification has altered the ocean's carbonate chemistry profoundly since preindustrial times, with potentially serious consequences for marine life. Yet, no long-term global observation-based data set exists that permits to study changes in ocean acidification for all carbonate system parameters over the last few decades. Here, we fill this gap and present a methodologically consistent global data set of all relevant surface ocean parameters, i.e., dissolved inorganic carbon (DIC), total alkalinity (TA), partial pressure of CO2 (pCO2), pH, and the saturation state with respect to mineral CaCO3 (Ω) at monthly resolution over the period 1985 through 2018 at a spatial resolution of 1 × 1°. This data set, named OceanSODA-ETHZ, was created by extrapolating in time and space the surface ocean observations of pCO2 (from the Surface Ocean CO2 ATlas (SOCAT)) and total alkalinity (TA, from the Global Ocean Data Analysis Project (GLODAP)) using the newly developed Geospatial Random Cluster Ensemble Regression (GRaCER) method. This method is based on a two-step (cluster-regression) approach, but extends it by considering an ensemble of such cluster-regressions, leading to higher robustness. Surface ocean DIC, pH, and Ω were then computed from the globally mapped pCO2 and TA using the thermodynamic equations of the carbonate system. For the open ocean, the cluster regression method estimates pCO2 and TA with global near-zero biases and root mean squared errors of 12 µatm and 13 µmol kg−1, respectively. Taking into account also the measurement and representation errors, the total error increases to 14 µatm and 21 µmol kg−1, respectively. We assess the fidelity of the computed parameters by comparing them to direct observations from GLODAP, finding surface ocean pH and DIC global biases of near zero, and root mean squared errors of 0.023 and 16 µmol kg−1, respectively. These errors are very comparable to those expected by propagating the total errors from pCO2 and TA through the thermodynamic computations, indicating a robust and conservative assessment of the errors. We illustrate the potential of this new dataset by analyzing the climatological mean seasonal cycles of the different parameters of the surface ocean carbonate system, highlighting their commonalities and differences. The OceanSODA-ETHZ data can be downloaded from https://doi.org/10.25921/m5wx-ja34 (Gregor and Gruber, 2020).

Ocean acidification as a multiple driver: how interactions between changing seawater carbonate parameters affect marine life

2020 ◽  
Vol 71 (3) ◽  
pp. 263 ◽  
Author(s):  
Catriona L. Hurd ◽  
John Beardall ◽  
Steeve Comeau ◽  
Christopher E. Cornwall ◽  
Jonathan N Havenhand ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Multiple Stressors ◽  
Rapid Expansion ◽  
Coralline Algae ◽  
Carbonate System ◽  
Saturation State ◽  
Marine Life ◽  
Key Terms

‘Multiple drivers’ (also termed ‘multiple stressors’) is the term used to describe the cumulative effects of multiple environmental factors on organisms or ecosystems. Here, we consider ocean acidification as a multiple driver because many inorganic carbon parameters are changing simultaneously, including total dissolved inorganic carbon, CO2, HCO3–, CO32–, H+ and CaCO3 saturation state. With the rapid expansion of ocean acidification research has come a greater understanding of the complexity and intricacies of how these simultaneous changes to the seawater carbonate system are affecting marine life. We start by clarifying key terms used by chemists and biologists to describe the changing seawater inorganic carbon system. Then, using key groups of non-calcifying (fish, seaweeds, diatoms) and calcifying (coralline algae, coccolithophores, corals, molluscs) organisms, we consider how various physiological processes are affected by different components of the carbonate system.

scholarly journals Development of a Biogeochemical and Carbon Model Related to Ocean Acidification Indices with an Operational Ocean Model Product in the North Western Pacific

2019 ◽  
Vol 11 (9) ◽  
pp. 2677 ◽  
Author(s):  
Miho Ishizu ◽  
Yasumasa Miyazawa ◽  
Tomohiko Tsunoda ◽  
Xinyu Guo
Keyword(s):  
Ocean Acidification ◽  
General Circulation ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Ocean Model ◽  
Western Pacific ◽  
Total Alkalinity ◽  
The North ◽  
North Western ◽  
North Western Pacific

We developed a biogeochemical and carbon model (JCOPE_EC) coupled with an operational ocean model for the North Western Pacific. JCOPE_EC represents ocean acidification indices on the background of the risks due to ocean acidification and our model experiences. It is an off-line tracer model driven by a high-resolution regional ocean general circulation model (JCOPE2M). The results showed that the model adequately reproduced the general patterns in the observed data, including the seasonal variability of chlorophyll-a, dissolved inorganic nitrogen/phosphorus, dissolved inorganic carbon, and total alkalinity. We provide an overview of this system and the results of the model validation based on the available observed data. Sensitivity analysis using fixed values for temperature, salinity, dissolved inorganic carbon and total alkalinity helped us identify which variables contributed most to seasonal variations in the ocean acidification indices, pH and Ωarg. The seasonal variation in the pHinsitu was governed mainly by balances of the change in temperature and dissolved inorganic carbon. The seasonal increase in Ωarg from winter to summer was governed mainly by dissolved inorganic carbon levels.

Organic and inorganic whole system metabolism in two acidified coastal systems in Ireland

2020 ◽  
Author(s):  
Maria Teresa Guerra ◽  
Carlos Rocha
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Carbonate System ◽  
Net Community Production ◽  
Coastal Acidification ◽  
Autumn And Winter ◽  
System Metabolism ◽  
Internal Buffer ◽  
Community Production

&lt;p&gt;Organic and inorganic whole system metabolism for two Irish coastal areas were compared to evaluate carbonate system resilience to acidification. The two systems are characterized by contrasting watershed input types and composition. Kinvara Bay is fed by Submarine Groundwater Discharge (SGD) derived from a karstic catchment while Killary Harbour is fed by river discharge draining a siliciclastic catchment. Freshwater sources to sea have distinct Total Alkalinity (TA) and Dissolved Inorganic Carbon (DIC) concentrations, higher and lower than the open ocean, respectively, but both evidence seasonally variable low pH, ranging from 6.20 to 7.50. Retention of TA and DIC was calculated for the two areas using LOICZ methodology. In Kinvara bay, annually averaged retention of DIC was greater than for TA (5 &amp;#215; 10&lt;sup&gt;4&lt;/sup&gt; and 1.5 &amp;#215; 10&lt;sup&gt;5&lt;/sup&gt; mol d&lt;sup&gt;-1&lt;/sup&gt;), suggesting the system is acidifying further. Conversely, Killary Harbour shows negative TA and DIC retention, with DIC:TA &lt;1, suggesting an internal buffer against ocean acidification is operating.&lt;/p&gt;&lt;p&gt;Net Community Production (NCP) was calculated for both systems using Dissolved Oxygen data. Subsequently, we estimated Net Community Calcification (NCC) from the ratio between TA and DIC. NCP was always positive in Killary Harbour with an average of 318 mmol O&lt;sub&gt;2&lt;/sub&gt; m&lt;sup&gt;-2 &lt;/sup&gt;d&lt;sup&gt;-1&lt;/sup&gt; (equivalent to 89 mol C m&lt;sup&gt;-2&lt;/sup&gt; y&lt;sup&gt;-1&lt;/sup&gt;). However, Kinvara Bay shows relatively lower positive NCP in spring and summer (average of 46 mmol O&lt;sub&gt;2&lt;/sub&gt; m&lt;sup&gt;-2&lt;/sup&gt; d&lt;sup&gt;-1&lt;/sup&gt;), but negative NCP in autumn and winter. Therefore, Kinvara Bay&amp;#8217;s Total Organic Carbon (TOC) production was low, at ~21 g m&lt;sup&gt;-2&lt;/sup&gt; y&lt;sup&gt;-1&lt;/sup&gt; and not enough to overcome acidification driven by the SGD source composition. These results emphasize the complexity of interactions between the drivers of coastal acidification rate, affecting our ability to accurately assess the resilience of the carbonate system in these areas to ocean acidification pressure in the future.&lt;/p&gt;

scholarly journals OceanSODA-ETHZ: a global gridded data set of the surface ocean carbonate system for seasonal to decadal studies of ocean acidification

2021 ◽  
Vol 13 (2) ◽  
pp. 777-808
Author(s):  
Luke Gregor ◽  
Nicolas Gruber
Keyword(s):  
Ocean Acidification ◽  
Total Alkalinity ◽  
Global Ocean ◽  
Carbonate System ◽  
Data Set ◽  
Saturation State ◽  
Total Uncertainty ◽  
Mean Squared Errors ◽  
Surface Ocean ◽  
Basin Scale

Abstract. Ocean acidification has profoundly altered the ocean's carbonate chemistry since preindustrial times, with potentially serious consequences for marine life. Yet, no long-term, global observation-based data set exists that allows us to study changes in ocean acidification for all carbonate system parameters over the last few decades. Here, we fill this gap and present a methodologically consistent global data set of all relevant surface ocean parameters, i.e., dissolved inorganic carbon (DIC), total alkalinity (TA), partial pressure of CO2 (pCO2), pH, and the saturation state with respect to mineral CaCO3 (Ω) at a monthly resolution over the period 1985 through 2018 at a spatial resolution of 1∘×1∘. This data set, named OceanSODA-ETHZ, was created by extrapolating in time and space the surface ocean observations of pCO2 (from the Surface Ocean CO2 Atlas, SOCAT) and total alkalinity (TA; from the Global Ocean Data Analysis Project, GLODAP) using the newly developed Geospatial Random Cluster Ensemble Regression (GRaCER) method (code available at https://doi.org/10.5281/zenodo.4455354, Gregor, 2021). This method is based on a two-step (cluster-regression) approach but extends it by considering an ensemble of such cluster regressions, leading to improved robustness. Surface ocean DIC, pH, and Ω were then computed from the globally mapped pCO2 and TA using the thermodynamic equations of the carbonate system. For the open ocean, the cluster-regression method estimates pCO2 and TA with global near-zero biases and root mean squared errors of 12 µatm and 13 µmol kg−1, respectively. Taking into account also the measurement and representation errors, the total uncertainty increases to 14 µatm and 21 µmol kg−1, respectively. We assess the fidelity of the computed parameters by comparing them to direct observations from GLODAP, finding surface ocean pH and DIC global biases of near zero, as well as root mean squared errors of 0.023 and 16 µmol kg−1, respectively. These uncertainties are very comparable to those expected by propagating the total uncertainty from pCO2 and TA through the thermodynamic computations, indicating a robust and conservative assessment of the uncertainties. We illustrate the potential of this new data set by analyzing the climatological mean seasonal cycles of the different parameters of the surface ocean carbonate system, highlighting their commonalities and differences. Further, this data set provides a novel constraint on the global- and basin-scale trends in ocean acidification for all parameters. Concretely, we find for the period 1990 through 2018 global mean trends of 8.6 ± 0.1 µmol kg−1 per decade for DIC, −0.016 ± 0.000 per decade for pH, 16.5 ± 0.1 µatm per decade for pCO2, and −0.07 ± 0.00 per decade for Ω. The OceanSODA-ETHZ data can be downloaded from https://doi.org/10.25921/m5wx-ja34 (Gregor and Gruber, 2020).

scholarly journals The Sensitivity of the Marine Carbonate System to Regional Ocean Alkalinity Enhancement

2021 ◽  
Vol 3 ◽  
Author(s):  
Daniel J. Burt ◽  
Friederike Fröb ◽  
Tatiana Ilyina
Keyword(s):  
Southern Ocean ◽  
Dissolved Inorganic Carbon ◽  
Ocean Model ◽  
Total Alkalinity ◽  
Surface Pattern ◽  
Carbon Uptake ◽  
Max Planck ◽  
Carbonate System ◽  
Carbon Cycle Model ◽  
Marine Carbonate

Ocean Alkalinity Enhancement (OAE) simultaneously mitigates atmospheric concentrations of CO2 and ocean acidification; however, no previous studies have investigated the response of the non-linear marine carbonate system sensitivity to alkalinity enhancement on regional scales. We hypothesise that regional implementations of OAE can sequester more atmospheric CO2 than a global implementation. To address this, we investigate physical regimes and alkalinity sensitivity as drivers of the carbon-uptake potential response to global and different regional simulations of OAE. In this idealised ocean-only set-up, total alkalinity is enhanced at a rate of 0.25 Pmol a-1 in 75-year simulations using the Max Planck Institute Ocean Model coupled to the HAMburg Ocean Carbon Cycle model with pre-industrial atmospheric forcing. Alkalinity is enhanced globally and in eight regions: the Subpolar and Subtropical Atlantic and Pacific gyres, the Indian Ocean and the Southern Ocean. This study reveals that regional alkalinity enhancement has the capacity to exceed carbon uptake by global OAE. We find that 82–175 Pg more carbon is sequestered into the ocean when alkalinity is enhanced regionally and 156 PgC when enhanced globally, compared with the background-state. The Southern Ocean application is most efficient, sequestering 12% more carbon than the Global experiment despite OAE being applied across a surface area 40 times smaller. For the first time, we find that different carbon-uptake potentials are driven by the surface pattern of total alkalinity redistributed by physical regimes across areas of different carbon-uptake efficiencies. We also show that, while the marine carbonate system becomes less sensitive to alkalinity enhancement in all experiments globally, regional responses to enhanced alkalinity vary depending upon the background concentrations of dissolved inorganic carbon and total alkalinity. Furthermore, the Subpolar North Atlantic displays a previously unexpected alkalinity sensitivity increase in response to high total alkalinity concentrations.

scholarly journals Current estimates of K<sub>1</sub>* and K<sub>2</sub>* appear inconsistent with measured CO<sub>2</sub> system parameters in cold oceanic regions

Ocean Science ◽  
2020 ◽  
Vol 16 (4) ◽  
pp. 847-862 ◽  
Author(s):  
Olivier Sulpis ◽  
Siv K. Lauvset ◽  
Mathilde Hagens
Keyword(s):  
Surface Water ◽  
Ocean Acidification ◽  
Carbonic Acid ◽  
Dissolved Inorganic Carbon ◽  
Dissociation Constants ◽  
Total Alkalinity ◽  
Global Ocean ◽  
Polar Regions ◽  
Carbonate System ◽  
System Variables

Abstract. Seawater absorption of anthropogenic atmospheric carbon dioxide (CO2) has led to a range of changes in carbonate chemistry, collectively referred to as ocean acidification. Stoichiometric dissociation constants used to convert measured carbonate system variables (pH, pCO2, dissolved inorganic carbon, total alkalinity) into globally comparable parameters are crucial for accurately quantifying these changes. The temperature and salinity coefficients of these constants have generally been experimentally derived under controlled laboratory conditions. Here, we use field measurements of carbonate system variables taken from the Global Ocean Data Analysis Project version 2 and the Surface Ocean CO2 Atlas data products to evaluate the temperature dependence of the carbonic acid stoichiometric dissociation constants. By applying a novel iterative procedure to a large dataset of 948 surface-water, quality-controlled samples where four carbonate system variables were independently measured, we show that the set of equations published by Lueker et al. (2000), currently preferred by the ocean acidification community, overestimates the stoichiometric dissociation constants at temperatures below about 8 ∘C. We apply these newly derived temperature coefficients to high-latitude Argo float and cruise data to quantify the effects on surface-water pCO2 and calcite saturation states. These findings highlight the critical implications of uncertainty in stoichiometric dissociation constants for future projections of ocean acidification in polar regions and the need to improve knowledge of what causes the CO2 system inconsistencies in cold waters.

scholarly journals An initial study on ocean acidification in Southern waters of Vietnam

2021 ◽  
Vol 21 (1) ◽  
pp. 47-55
Author(s):  
Phu Le Hung ◽  
Tuan Linh Vo Tran ◽  
Ngoc Pham Hong
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Initial Study ◽  
The State ◽  
Total Alkalinity ◽  
Saturation State ◽  
Aragonite Saturation ◽  
Mean Values ◽  
Co2 Partial Pressure ◽  
Average Value

Ocean acidification (OA) refers to the increase of dissolved CO2 and the reduction in the pH of seawater as a consequence of the absorption of large amounts of carbon dioxide (CO2) by the oceans. This process is the result of large quantities of CO2, produced by vehicles and industrial and agricultural activities. Over the past decades there have been many worldwide studies focusing on potential impacts of OA. However, researches regarding this issue remain scarce in Vietnam. In this paper, data of pH, total alkalinity (TA), dissolved inorganic carbon (HCO3-, CO32-, CO2), partial pressure of CO2 (pCO2) and the state of aragonite saturation (Ωar) measured in Southern waters of Vietnam in 2018 were used to: (1) Provide the initial data of OA parameters in Southern waters of Vietnam; (2) Compare the current situation of OA in Southern waters of Vietnam with the situation of world oceans. The results showed that mean values of pH, TA and CO32- concentrations were 8.04 (7.92–8.11), 2300.28 µmol/kgSW (2,144.10–2,523.15), 218.83 µmol/kgSW (151.32–262.83), respectively. These values were higher in offshore areas than in coastal areas, especially at the estuaries. The average value of pCO2 was 414.47 µatm (327.93–568.59), higher when compared with that of other areas (370 µatm). On the other hand, the state of aragonite saturation of the studied area had the similar patterns of TA and CO32- concentrations. Most of values were always greater than 3, with this saturation state, the marine calcifiers are more likely to survive and reproduce.

scholarly journals Current estimates of K<sub>1</sub><sup>*</sup> and K<sub>2</sub><sup>*</sup> appear inconsistent with measured CO<sub>2</sub> system parameters in cold oceanic regions

2020 ◽  
Author(s):  
Olivier Sulpis ◽  
Siv K. Lauvset ◽  
Mathilde Hagens
Keyword(s):  
Surface Water ◽  
Ocean Acidification ◽  
Carbonic Acid ◽  
Dissolved Inorganic Carbon ◽  
Dissociation Constants ◽  
Total Alkalinity ◽  
Global Ocean ◽  
Polar Regions ◽  
Carbonate System ◽  
System Variables

Abstract. Seawater absorption of anthropogenic atmospheric carbon dioxide (CO2) has led to a range of changes in carbonate chemistry, collectively referred to as ocean acidification. Stoichiometric dissociation constants used to convert measured carbonate system variables (pH, pCO2, dissolved inorganic carbon, total alkalinity) into globally comparable parameters are crucial for accurately quantifying these changes. The temperature and salinity coefficients of these constants have generally been experimentally derived under controlled laboratory conditions. Here, we use field measurements of carbonate system variables taken from the Global Ocean Data Analysis Project version 2 and the Surface Ocean CO2 Atlas databases to evaluate the temperature dependence of the carbonic acid stoichiometric dissociation constants. By applying a novel iterative procedure to a large dataset of 948 surface-water, quality-controlled samples where four carbonate system variables were independently measured, we show that the set of equations published by Lueker et al. (2000), currently preferred by the ocean acidification community, overestimates the stoichiometric dissociation constants at low temperatures, below ~ 8 °C. We apply these newly derived temperature coefficients to high-latitude Argo float and cruise data to quantify the effects on surface-water pCO2 and calcite saturation states. These findings highlight the critical implications of uncertainty in stoichiometric dissociation constants for future projections of ocean acidification in polar regions, and the need to improve knowledge of what causes the CO2 system inconsistencies in cold waters.

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