scholarly journals Evidence for preindustrial variations in the marine surface water carbonate system from coralline sponges

2002 ◽  
Vol 3 (3) ◽  
pp. 1-13 ◽  
Author(s):  
F. Böhm ◽  
A. Haase-Schramm ◽  
A. Eisenhauer ◽  
W.-C. Dullo ◽  
M. M. Joachimski ◽  
...  
Keyword(s):  
Surface Water ◽  
Carbonate System ◽  
Marine Surface ◽  
Water Carbonate

scholarly journals Ocean acidification state in western Antarctic surface waters: drivers and interannual variability

2013 ◽  
Vol 10 (5) ◽  
pp. 7879-7916 ◽  
Author(s):  
M. Mattsdotter Björk ◽  
A. Fransson ◽  
M. Chierici
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Interannual Variability ◽  
Chlorophyll A ◽  
Total Alkalinity ◽  
Full Description ◽  
Carbonate System ◽  
Amundsen Sea ◽  
Water Carbonate

Abstract. Each December during four years from 2006 to 2010, the surface water carbonate system was measured and investigated in the Amundsen Sea and Ross Sea, western Antarctica as part of the Oden Southern Ocean expeditions (OSO). The I/B Oden started in Punta Arenas in Chile and sailed southwest, passing through different regimes such as, the marginal/seasonal ice zone, fronts, coastal shelves, and polynyas. Discrete surface water was sampled underway for analysis of total alkalinity (AT), total dissolved inorganic carbon (CT) and pH. Two of these parameters were used together with sea-surface temperature (SST), and salinity to obtain a full description of the surface water carbonate system, including pH in situ and calcium carbonate saturation state of aragonite (ΩAr) and calcite (ΩCa). Multivariate analysis was used to investigate interannual variability and the major controls (sea-ice concentration, SST, salinity and chlorophyll a) on the variability in the carbonate system and Ω. This analysis showed that SST and chlorophyll a were the major drivers of the Ω variability in both the Amundsen and Ross seas. In 2007, the sea-ice edge was located further south and the area of the open polynya was relatively small compared to 2010. We found the lowest pH in situ (7.932) and Ω = 1 values in the sea-ice zone and in the coastal Amundsen Sea, nearby marine out flowing glaciers. In 2010, the sea-ice coverage was the largest and the areas of the open polynyas were the largest for the whole period. This year we found the lowest salinity and AT, coinciding with highest chl a. This implies that the highest ΩAr in 2010 was likely an effect of biological CO2 drawdown, which out-competed the dilution of carbonate ion concentration due to large melt water volumes. We predict and discuss future Ω values, using our data and reported rates of oceanic uptake of anthropogenic CO2, suggesting that the Amundsen Sea will become undersaturated with regard to aragonite about 20 yr sooner than predicted by models.

scholarly journals Rapid changes in surface water carbonate chemistry during Antarctic sea ice melt

Tellus B ◽  
2010 ◽  
Vol 62 (5) ◽  
pp. 621-635 ◽  
Author(s):  
Elizabeth Jones ◽  
Dorothee Bakker ◽  
Hugh Venables ◽  
Michael Whitehouse ◽  
Rebecc Korb ◽  
...  
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Carbonate Chemistry ◽  
Ice Melt ◽  
Antarctic Sea Ice ◽  
Rapid Changes ◽  
Water Carbonate

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.

Ocean acidification and surface water carbonate production across the Paleocene–Eocene thermal maximum

2010 ◽  
Vol 295 (3-4) ◽  
pp. 583-592 ◽  
Author(s):  
Samantha J. Gibbs ◽  
Heather M. Stoll ◽  
Paul R. Bown ◽  
Timothy J. Bralower
Keyword(s):  
Surface Water ◽  
Ocean Acidification ◽  
Carbonate Production ◽  
Thermal Maximum ◽  
Water Carbonate

scholarly journals Winter to summer evolution of <i>p</i>CO<sub>2</sub> in surface water and air–sea CO<sub>2</sub> flux in the seasonal ice zone of the Southern Ocean

2014 ◽  
Vol 11 (1) ◽  
pp. 657-690 ◽  
Author(s):  
D. Nomura ◽  
H. Yoshikawa-Inoue ◽  
S. Kobayashi ◽  
S. Nakaoka ◽  
K. Nakata ◽  
...  
Keyword(s):  
Surface Water ◽  
Southern Ocean ◽  
Sea Ice ◽  
Water Temperature ◽  
Co2 Flux ◽  
Biological Productivity ◽  
Carbonate System ◽  
Sea Ice Concentration ◽  
Co2 Sink ◽  
Seasonal Ice Zone

Abstract. Partial pressure of CO2 (pCO2) in surface water and vertical profiles of the aqueous carbonate system were measured during austral summer in the Indian sector of the Southern Ocean (64–67° S, 32–58° E) in January~2006 to understand the CO2 dynamics of seawater in the seasonal ice zone. Surface-water pCO2 ranged from 275 to 400 μatm, and longitudinal variations reflected the dominant influence of water temperature and dilution by sea-ice meltwater between 32° and 40° E and biological productivity between 40° and 58° E. Using carbonate system data from the temperature minimum layer, we examined the winter-to-summer evolution of surface-water pCO2 and the factors affecting it. Our results indicate that pCO2 increased by as much as 32 μatm, resulting mainly from the increase in water temperature. In synchrony with changes in sea ice concentration and surface-water pCO2, air–sea CO2 flux with considering the exchange of CO2 between sea ice and atmosphere, changed from −1.1 to +0.9 mmol C m−2 day−1 between winter and summer. These results suggest that for the atmosphere, the seasonal ice zone acts as a CO2 sink in winter and a CO2 source in summer immediately after ice melt. Subsequent biological productivity likely decreases surface-water pCO2 and air–sea CO2 flux becomes negative, such that in summer the study area is a CO2 sink with respect to the atmosphere.

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