scholarly journals Global net community production estimated from the annual cycle of surface water total dissolved inorganic carbon

2001 ◽  
Vol 46 (6) ◽  
pp. 1287-1297 ◽  
Author(s):  
Kitack Lee
Keyword(s):  
Surface Water ◽  
Annual Cycle ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Net Community Production ◽  
Total Dissolved Inorganic Carbon ◽  
Community Production

scholarly journals Net community production and stoichiometry of nutrient consumption in a pelagic ecosystem of a northern high latitude fjord: mesocosm CO<sub>2</sub> perturbation study

2012 ◽  
Vol 9 (8) ◽  
pp. 11705-11737 ◽  
Author(s):  
A. Silyakova ◽  
R. G. J. Bellerby ◽  
J. Czerny ◽  
K. G. Schulz ◽  
G. Nondal ◽  
...  
Keyword(s):  
Large Scale ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
P Uptake ◽  
Nutrient Addition ◽  
Net Community Production ◽  
Cumulative Change ◽  
Nutrient Consumption ◽  
Community Production ◽  
Three Phases

Abstract. Net community production (NCP) and ratios of carbon to nutrient consumption were studied during a large-scale mesocosm experiment on ocean acidification in Kongsfjorden, West Spitsbergen, during June–July 2010. Nutrient-deplete fjord water with natural phyto- and bacteriaplankton assemblages, enclosed in nine mesocosms of ~ 50 m3 volume, was exposed to pCO2 levels ranging from 185 to 1420 μatm on initial state. Mean values of pCO2 levels during experiment ranged from 175 to 1085 μatm in different mesocosms. Phytoplankton growth was stimulated by nutrient addition. In this study NCP is estimated as a cumulative change in dissolved inorganic carbon concentrations. Stoichiometric couping between inorganic carbon and nutrient is shown as a ratio of a cumulative NCP to a cumulative change in inorganic nutrients. Three peaks of chlorophyll a concentration occurred during the experiment. Accordingly the experiment was divided in three phases. Overall cumulative NCP was similar in all mesocosms by the final day of experiment. However, NCP varied among phases, showing variable response to CO2 perturbation. Carbon to nitrogen (C : N) and carbon to phosphorus (C : P) uptake ratios were estimated only for the period after nutrient addition (post-nutrient period). For the total post-nutrient period ratios were close to Redfield proportions, however varied from it in different phases. The response of C : N and C : P uptake ratios to CO2 perturbation was different for three phases of the experiment, reflecting variable NCP and dependence on changing microbial community. Through the variable NCP, C : N and C : P uptake ratios for 31 days of the experiment we show a flexibility of biogeochemical response establishing a strong microbial loop in Kongsfjorden under different CO2 scenarios.

scholarly journals Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf

2010 ◽  
Vol 7 (1) ◽  
pp. 251-300 ◽  
Author(s):  
J. T. Mathis ◽  
J. N. Cross ◽  
N. R. Bates ◽  
S. B. Moran ◽  
M. W. Lomas ◽  
...  
Keyword(s):  
Primary Production ◽  
Bering Sea ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Inner Shelf ◽  
Net Community Production ◽  
Important Indicator ◽  
Bering Sea Shelf ◽  
Community Production ◽  
The Bering Sea

Abstract. The southeastern shelf of the Bering Sea is one of the ocean's most productive ecosystems and sustains more than half of the total US fish landings annually. However, the character of the Bering Sea shelf ecosystem has undergone a dramatic shift over the last several decades, causing notable increases in the dominance of temperate features coupled to the decline of arctic species and decreases in the abundance of commercially important organisms. In order to assess the current state of primary production in the southeastern Bering Sea, we measured the spatio-temporal distribution and controls on dissolved inorganic carbon (DIC) concentrations in spring and summer of 2008 across six shelf domains defined by differing biogeochemical characteristics. DIC concentrations were tightly coupled to salinity in spring and ranged from ~1900 μmol kg−1 over the inner shelf to ~2400 μmol kg−1 in the deeper waters of the Bering Sea. In summer, DIC concentrations were lower due to dilution from sea ice melt and primary production. Concentrations were found to be as low ~1800 μmol kg−1 over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmol kg−1 in the upper 30 m of the water column due to primary production between the spring and summer occupations. Using the seasonal drawdown of DIC, estimated rates of net community production (NCP) on the inner, middle, and outer shelf averaged 28±10 mmol C m−2 d−1. However, higher rates of NCP (40–47 mmol C m−2 d−1) were observed in the ''Green Belt'' where the greatest confluence of nutrient-rich basin water and iron-rich shelf water occurs. We estimated that in 2008, total productivity across the shelf was on the order of ~105 Tg C yr−1. Due to the paucity of consistent, comparable productivity data, it is impossible at this time to quantify whether the system is becoming more or less productive. However, as changing climate continues to modify the character of the Bering Sea, we have shown that NCP can be an important indicator of how the ecosystem is functioning.

scholarly journals Fluxes of carbon and nutrients to the Iceland Sea surface layer and inferred primary productivity and stoichiometry

2014 ◽  
Vol 11 (11) ◽  
pp. 15399-15433
Author(s):  
E. Jeansson ◽  
R. G. J. Bellerby ◽  
I. Skjelvan ◽  
H. Frigstad ◽  
S. R. Ólafsdóttir ◽  
...  
Keyword(s):  
Surface Layer ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Vertical Mixing ◽  
Sea Surface ◽  
Net Community Production ◽  
Horizontal Advection ◽  
Vertical Fluxes ◽  
Biological Uptake ◽  
Community Production

Abstract. Fluxes of carbon and nutrients to the upper 100 m of the Iceland Sea are evaluated. The study utilises hydro-chemical data from the Iceland Sea time-series station (68.00° N, 12.67° W), for the years between 1993 and 2006. By comparing data of dissolved inorganic carbon (DIC) and nutrients in the surface layer (upper 100 m), and a sub-surface layer (100–200 m), we calculate monthly deficits in the surface, and use these to deduce the surface layer fluxes that affect the deficits: vertical mixing, horizontal advection, air–sea exchange, and biological activity. The deficits show a clear seasonality with a minimum in winter, when the mixed layer is at the deepest, and a maximum in early autumn, when biological uptake has removed much of the nutrients. The annual vertical fluxes of DIC and nitrate amounts to 1.7 ± 0.3 and 0.23 ± 0.07 mol m−2 yr−1, respectively, and the annual air–sea uptake of atmospheric CO2 is 4.4 ± 1.1 mol m−2 yr−1. The biologically driven changes in DIC during the year relates to net community production (NCP), and the net annual NCP corresponds to export production, and is here calculated to 6.1 ± 0.9 mol C m−2 yr−1. The typical, median C : N ratio during the period of net community uptake is 11, and thus clearly higher than Redfield, but is varying during the season.

scholarly journals Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf

2010 ◽  
Vol 7 (5) ◽  
pp. 1769-1787 ◽  
Author(s):  
J. T. Mathis ◽  
J. N. Cross ◽  
N. R. Bates ◽  
S. Bradley Moran ◽  
M. W. Lomas ◽  
...  
Keyword(s):  
Primary Production ◽  
Bering Sea ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Inner Shelf ◽  
Net Community Production ◽  
Important Indicator ◽  
Carbonate Formation ◽  
Community Production ◽  
The Bering Sea

Abstract. In order to assess the current state of net community production (NCP) in the southeastern Bering Sea, we measured the spatio-temporal distribution and controls on dissolved inorganic carbon (DIC) concentrations in spring and summer of 2008 across six shelf domains defined by differing biogeochemical characteristics. DIC concentrations were tightly coupled to salinity in spring and ranged from ~1900 μmoles kg−1 over the inner shelf to ~2400 μmoles kg−1 in the deeper waters of the Bering Sea. In summer, DIC concentrations were lower due to dilution from sea ice melt, terrestrial inputs, and primary production. Concentrations were found to be as low ~1800 μmoles kg−1 over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmoles kg−1 in the upper 30 m of the water column due to primary production and calcium carbonate formation between the spring and summer occupations. Using the seasonal drawdown of DIC, estimated rates of NCP on the inner, middle, and outer shelf averaged 28 ± 9 mmoles C m−2 d−1. However, higher rates of NCP (40–47 mmoles C m−2 d−1) were observed in the "Green Belt" where the greatest confluence of nutrient-rich basin water and iron-rich shelf water occurs. We estimated that in 2008, total NCP across the shelf was on the order of ~96 Tg C yr−1. Due to the paucity of consistent, comparable productivity data, it is impossible at this time to quantify whether the system is becoming more or less productive. However, as changing climate continues to modify the character of the Bering Sea, we have shown that NCP can be an important indicator of how the ecosystem is functioning.

scholarly journals Fluxes of carbon and nutrients to the Iceland Sea surface layer and inferred primary productivity and stoichiometry

2015 ◽  
Vol 12 (3) ◽  
pp. 875-885 ◽  
Author(s):  
E. Jeansson ◽  
R. G. J. Bellerby ◽  
I. Skjelvan ◽  
H. Frigstad ◽  
S. R. Ólafsdóttir ◽  
...  
Keyword(s):  
Surface Layer ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Vertical Mixing ◽  
Sea Surface ◽  
Net Community Production ◽  
Horizontal Advection ◽  
Vertical Fluxes ◽  
Community Production

Abstract. This study evaluates long-term mean fluxes of carbon and nutrients to the upper 100 m of the Iceland Sea. The study utilises hydro-chemical data from the Iceland Sea time series station (68.00° N, 12.67° W), for the years between 1993 and 2006. By comparing data of dissolved inorganic carbon (DIC) and nutrients in the surface layer (upper 100 m), and a sub-surface layer (100–200 m), we calculate monthly deficits in the surface, and use these to deduce the long-term mean surface layer fluxes that affect the deficits: vertical mixing, horizontal advection, air–sea exchange, and biological activity. The deficits show a clear seasonality with a minimum in winter, when the mixed layer is at the deepest, and a maximum in early autumn, when biological uptake has removed much of the nutrients. The annual vertical fluxes of DIC and nitrate amounts to 2.9 ± 0.5 and 0.45 ± 0.09 mol m−2 yr−1, respectively, and the annual air–sea uptake of atmospheric CO2 is 4.4 ± 1.1 mol C m−2 yr−1. The biologically driven changes in DIC during the year relates to net community production (NCP), and the net annual NCP corresponds to export production, and is here calculated as 7.3 ± 1.0 mol C m−2 yr−1. The typical, median C : N ratio during the period of net community uptake is 9.0, and clearly higher than the Redfield ratio, but is varying during the season.

scholarly journals Inorganic carbon time series at Ocean Weather Station M in the Norwegian Sea

2007 ◽  
Vol 4 (4) ◽  
pp. 2929-2958 ◽  
Author(s):  
I. Skjelvan ◽  
E. Falck ◽  
F. Rey ◽  
S. B. Kringstad
Keyword(s):  
Surface Water ◽  
Deep Water ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Sea Surface ◽  
Linear Regression Method ◽  
Weather Station ◽  
Arctic Water ◽  
Annual Increase ◽  
Norwegian Sea

Abstract. Dissolved inorganic carbon (CT) has been collected at Ocean Weather Station M (OWSM) in the Norwegian Sea since 2001. Seasonal variations in CT are confined to the upper 50 m, where the biology is active, and below this layer no clear seasonal signal is seen. From winter to summer the surface CT concentration typical drops from 2140 to about 2040 μmol kg−1, while a deep water CT concentration of about 2163 μmol kg−1 is measured throughout the year. Observations show an annual increase in salinity normalized carbon concentration (nCT) of 1.3±0.7 μmol kg−1 in the surface layer, which is equivalent to a pCO2 increase of 2.6±1.2 μatm yr−1, i.e. larger than the atmospheric increase in this area. Observations also show an annual increase in the deep water nCT of 0.57± 0.24 μmol kg−1, of which about a tenth is due to inflow of old Arctic water with larger amounts of remineralised matter. The remaining part has an anthropogenic origin and sources for this might be Greenland Sea surface water, Iceland Sea surface water, and/or recirculated Atlantic Water. By using an extended multi linear regression method (eMLR) it is verified that anthropogenic carbon has entered the whole water column at OWSM.

scholarly journals Texas A&M University Radiocarbon Dates IV

Radiocarbon ◽  
1978 ◽  
Vol 20 (3) ◽  
pp. 455-460 ◽  
Author(s):  
R A Parker ◽  
W M Sackett
Keyword(s):  
Water Column ◽  
Mississippi River ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
River Delta ◽  
Cariaco Basin ◽  
Mississippi River Delta ◽  
Radiocarbon Dates ◽  
Carbonate Carbon ◽  
Total Dissolved Inorganic Carbon

Organic and carbonate carbon in sediments deposited in the Cariaco Basin and on the Mississippi River Delta and the total dissolved inorganic carbon in four water column profiles comprise the samples in this list. Except as noted below the samples were processed using the benzene synthesis and other procedures described by Mathews, et al (1972).

scholarly journals Inorganic carbon time series at Ocean Weather Station M in the Norwegian Sea

2008 ◽  
Vol 5 (2) ◽  
pp. 549-560 ◽  
Author(s):  
I. Skjelvan ◽  
E. Falck ◽  
F. Rey ◽  
S. B. Kringstad
Keyword(s):  
Surface Water ◽  
Deep Water ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Sea Surface ◽  
Linear Regression Method ◽  
Weather Station ◽  
Arctic Water ◽  
Annual Increase ◽  
Norwegian Sea

Abstract. Dissolved inorganic carbon (CT) has been collected at Ocean Weather Station M (OWSM) in the Norwegian Sea since 2001. Seasonal variations in (CT) are confined to the upper 50 m, where the biology is active, and below this layer no clear seasonal signal is seen. From winter to summer the surface (CT) concentration typical drop from 2140 to about 2040 μmol kg−1, while a deep water (CT) concentration of about 2163 μmol kg−1 is measured throughout the year. Observations show an annual increase in salinity normalized carbon concentration (nCT) of 1.3±0.7 μmol kg−1 yr−1 in the surface layer, which is equivalent to a pCO2 increase of 2.6±1.2 μatm yr−1, i.e. larger than the atmospheric increase in this area (2.1±0.2 μatm yr-1). Observations also show an annual increase in the deep water nCT of 0.57±0.24 μmol kg−1 yr−1, of which about 15% is due to inflow of old Arctic water with larger amounts of remineralised matter. The remaining part has an anthropogenic origin and sources for this might be Greenland Sea surface water, Iceland Sea surface water, and/or recirculated Atlantic Water. By using an extended multi linear regression method (eMLR) it is verified that anthropogenic carbon has entered the whole water column at OWSM.

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