scholarly journals Global Distribution of Total Inorganic Carbon and Total Alkalinity below the Deepest Winter Mixed Layer Depths

2000 ◽  
Author(s):  
C. Goyet ◽  
R. Healy ◽  
J. Ryan ◽  
A. Kozyr
Keyword(s):  
Mixed Layer ◽  
Inorganic Carbon ◽  
Global Distribution ◽  
Total Alkalinity ◽  
Total Inorganic Carbon ◽  
Winter Mixed Layer

scholarly journals Carbonate system distribution, anthropogenic carbon and acidification in the western tropical South Pacific (OUTPACE 2015 transect)

2018 ◽  
Vol 15 (16) ◽  
pp. 5221-5236 ◽  
Author(s):  
Thibaut Wagener ◽  
Nicolas Metzl ◽  
Mathieu Caffin ◽  
Jonathan Fin ◽  
Sandra Helias Nunige ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
South Pacific ◽  
Total Alkalinity ◽  
Total Inorganic Carbon ◽  
Saturation State ◽  
Anthropogenic Carbon ◽  
Subsurface Waters ◽  
Derived Properties ◽  
Intermediate Waters ◽  
South Pacific Gyre

Abstract. The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise, 18 February, 3 April 2015) for the measurement of carbonate parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago (MA) and the western part of the South Pacific gyre (WGY). This paper reports this new dataset and derived properties: pH on the total scale (pHT) and the CaCO3 saturation state with respect to aragonite (Ωara). We also estimate anthropogenic carbon (CANT) distribution in the water column using the TrOCA method (Tracer combining Oxygen, inorganic Carbon and total Alkalinity). Along the OUTPACE transect a deeper penetration of CANT in the intermediate waters was observed in the MA, whereas highest CANT concentrations were detected in the subsurface waters of the WGY. By combining our OUTPACE dataset with data available in GLODAPv2 (1974–2009), temporal changes in oceanic inorganic carbon were evaluated. An increase of 1.3 to 1.6 µmol kg−1 a−1 for total inorganic carbon in the upper thermocline waters is estimated, whereas CANT increases by 1.1 to 1.2 µmol kg−1 a−1. In the MA intermediate waters (27 kg m−3 <σθ<27.2 kg m−3) an increase of 0.4 µmol kg−1 a−1 CANT is detected. Our results suggest a clear progression of ocean acidification in the western tropical South Pacific with a decrease in the oceanic pHT of up to −0.0027 a−1 and a shoaling of the saturation depth for aragonite of up to 200 m since the pre-industrial period.

scholarly journals Total dissolved inorganic carbon and physicochemical characteristics of surface microlayer and upper mixed layer water from Lagos Lagoon, Nigeria

2015 ◽  
Vol 17 (2) ◽  
pp. 334-343 ◽  
Keyword(s):  
Mixed Layer ◽  
Coastal Lagoon ◽  
Water Samples ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Physicochemical Characteristics ◽  
Total Alkalinity ◽  
Surface Microlayer ◽  
Total Dissolved Inorganic Carbon ◽  
Upper Mixed Layer

<p>The carbonate and physicochemical characteristics of the surface microlayer and upper mixed layer of a tropical coastal lagoon were investigated. Data on the physicochemical parameters generally indicated a moderately polluted ecosystem. The influence of the ocean environment over the Lagoon system was evident by elevated salinity levels. The mean total dissolved inorganic carbon (DIC) for the surface microlayer (SML) and subsurface water (SSW) samples were 2626.6 and 2550.9 &micro;mol/kg SW respectively. The dominant inorganic form of DIC in the lagoon water samples was HCO<sub>3</sub><sup>-</sup> with a calculated average abundance &gt;95.4% in the SML and &gt;94% in the SSW. The bicarbonate species derived abundance varied between 1.6% (SML) and 8.4% (SSW), while the aqueous carbon dioxide were generally low in percentages ranging from 0.4 in SSW to 1.5 in SML water samples. In general, the occurrence of the carbonate species was in the order HCO<sub>3</sub><sup>-</sup> &gt; CO<sub>3</sub><sup>2-</sup> &gt; CO<sub>2</sub>. Results showed that total alkalinity (A<sub>T</sub>) was relatively greater than the DIC. Long term monitoring studies in the coastal lagoon systems is needed to understand the coastal water chemistry and pollution status.</p>

scholarly journals Climatological variations of total alkalinity and total inorganic carbon in the Mediterranean Sea surface waters

2015 ◽  
Vol 6 (2) ◽  
pp. 1499-1533 ◽  
Author(s):  
E. Gemayel ◽  
A. E. R. Hassoun ◽  
M. A. Benallal ◽  
C. Goyet ◽  
P. Rivaro ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Surface Waters ◽  
Inorganic Carbon ◽  
World Ocean ◽  
Sea Surface ◽  
Total Alkalinity ◽  
Total Inorganic Carbon ◽  
Eastern Basin ◽  
Marginal Seas ◽  
The Mediterranean

Abstract. A compilation of several cruises data from 1998 to 2013 was used to derive polynomial fits that estimate total alkalinity (AT) and total inorganic carbon (CT) from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross validation results and revealed that a second and third order polynomials fit the AT and CT data respectively. The AT surface fit showed an improved root mean square error (RMSE) of ±10.6 μmol kg−1. Furthermore we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ±14.3 μmol kg−1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The seven years averages (2005–2012) mapped using the quarter degree climatologies of the World Ocean Atlas 2013 showed that in surface waters AT and CT have similar patterns with an increasing eastward gradient. The surface variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin, primarily due to the deepening of the mixed layer and upwelling of dense waters. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations.

scholarly journals The water column distribution of carbonate system variables at the ESTOC site from 1995 to 2004

2010 ◽  
Vol 7 (10) ◽  
pp. 3067-3081 ◽  
Author(s):  
M. González-Dávila ◽  
J. M. Santana-Casiano ◽  
M. J. Rueda ◽  
O. Llinás
Keyword(s):  
Carbon Dioxide ◽  
Time Series ◽  
Mixed Layer ◽  
Atmospheric Carbon Dioxide ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Anthropogenic Co2 ◽  
Rate Of Increase ◽  
Atmospheric Carbon

Abstract. The accelerated rate of increase in atmospheric carbon dioxide and the substantial fraction of anthropogenic CO2 emissions absorbed by the oceans are affecting the anthropocenic signatures of seawater. Long-term time series are a powerful tool for investigating any change in ocean bio-geochemistry and its effects on the carbon cycle. We have evaluated the ESTOC (European Station for Time series in the Ocean at the Canary islands) observations of measured pH (total scale at 25 °C) and total alkalinity plus computed total dissolved inorganic carbon concentration (CT) from 1995 to 2004 for surface and deep waters, by following all changes in response to increasing atmospheric carbon dioxide. The observed values for the surface partial pressure of CO2 from 1995 to 2008 were also taken into consideration. The data were treated to better understand the fundamental processes controlling vertical distributions in the Eastern North Atlantic Ocean and the accumulation of anthropogenic CO2, CANT. CT at constant salinity, NCT, increased at a rate of 0.85 μmol kg−1 yr−1 in the mixed layer, linked to an fCO2 increase of 1.7±0.7 μatm yr−1 in both the atmosphere and the ocean. Consequently, the mixed layer at ESTOC site has also become more acidic, −0.0017±0.0003 units yr−1, whereas the carbonate ion concentrations and CaCO3 saturation states have also decreased over time. NCT increases at a rate of 0.53, 0.49 and 0.40 μmol kg−1 yr−1 at 300, 600, and 1000 m, respectively. The general processes controlling the vertical variations of alkalinity and the inorganic carbon distribution were computed by considering the pre-formed values, the production/decomposition of organic matter and the formation/dissolution of carbonates. At 3000 m, 30% of the inorganic carbon production is related to the dissolution of calcium carbonate, increasing to 35% at 3685 m. The total column inventory of anthropogenic CO2 for the decade was 66±3 mol m−2. A model fitting indicated that the column inventory of CANT increased from 61.7 mol m−2 in the year 1994 to 70.2 mol m−2 in 2004. The ESTOC site is presented as a reference site to follow CANT changes in the Northeast Atlantic Sub-tropical gyre.

scholarly journals Carbonate system distribution, anthropogenic carbon and acidification in the Western Tropical South Pacific (OUTPACE 2015 transect)

2018 ◽  
Author(s):  
Thibaut Wagener ◽  
Nicolas Metzl ◽  
Mathieu Caffin ◽  
Jonathan Fin ◽  
Sandra Helias Nunige ◽  
...  
Keyword(s):  
Surface Waters ◽  
Inorganic Carbon ◽  
South Pacific ◽  
Total Alkalinity ◽  
Total Inorganic Carbon ◽  
Saturation State ◽  
Anthropogenic Carbon ◽  
Derived Properties ◽  
Intermediate Waters ◽  
South Pacific Gyre

Abstract. The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise, 18 Feb., 3 Apr. 2015) for measurement of carbonates parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago (MA) and the western part of the South Pacific gyre (WGY). This manuscript reports this new dataset and derived properties: pH on the total scale (pHT) and the CaCO3 saturation state with respect to calcite (Ωcal) and aragonite (Ωara). We also estimate anthropogenic carbon (CANT) distribution in the water column using the TrOCA method (Tracer combining Oxygen, inorganic Carbon and total Alkalinity). Along the OUTPACE transect, CANT inventories of 37–43 mol m−2 were estimated with higher CANT inventories in MA waters (due to a deeper penetration of CANT in the intermediate waters) than in the WGY waters although highest CANT concentrations were detected in the sub-surface waters of WGY. By combining our OUTPACE dataset with data available in GLODAPv2 (1974–2009), temporal changes in oceanic inorganic carbon were evaluated. An increase of 1.3 to 1.6 µmol kg−1 a−1 for total inorganic carbon in the upper thermocline waters is estimated whereas CANT increases of 1.1 to 1.2 µmol kg−1 a−1. In the MA intermediate waters (27 kg m−3 < σθ < 27.2 kg m−3) an increase of 0.4 µmol kg−1 a−1 of CANT is detected. Our results suggest a clear progression of ocean acidification in the western tropical South Pacific with a decrease of the oceanic pH of up to −0.0027 a−1 and a shoaling of the saturation depth for aragonite of up to 200 m since the pre-industrial period.

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