Applying the adjoint method for biogeochemical modeling: Export of participate organic matter in the world ocean

2000 ◽  
pp. 107-124 ◽  
Author(s):  
Reiner Schlitzer
Keyword(s):  
Organic Matter ◽  
Adjoint Method ◽  
World Ocean ◽  
Biogeochemical Modeling ◽  
The World

scholarly journals Revisiting the disappearance of terrestrial dissolved organic matter in the ocean: a <i>δ</i><sup>13</sup>C study

2014 ◽  
Vol 11 (13) ◽  
pp. 3707-3719 ◽  
Author(s):  
K. Lalonde ◽  
A. V. Vähätalo ◽  
Y. Gélinas
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Solar Radiation ◽  
World Ocean ◽  
Photochemical Reactions ◽  
Global Ocean ◽  
Terrestrial Organic Matter ◽  
The World ◽  
Radiation Induced ◽  
Simulated Solar Radiation

Abstract. Organic carbon (OC) depleted in 13C is a widely used tracer for terrestrial organic matter (OM) in aquatic systems. Photochemical reactions can, however, change δ13C of dissolved organic carbon (DOC) when chromophoric, aromatic-rich terrestrial OC is selectively mineralized. We assessed the robustness of the δ13C signature of DOC (δ13CDOC) as a tracer for terrestrial OM by estimating its change during the photobleaching of chromophoric DOM (CDOM) from 10 large rivers. These rivers cumulatively account for approximately one-third of the world's freshwater discharge to the global ocean. Photobleaching of CDOM by simulated solar radiation was associated with the photochemical mineralization of 16 to 43% of the DOC and, by preferentially removing compounds depleted in 13C, caused a 1 to 2.9‰ enrichment in δ13C in the residual DOC. Such solar-radiation-induced photochemical isotopic shift could bias the calculations of terrestrial OM discharge in coastal oceans towards the marine end-member. Shifts in terrestrial δ13CDOC should be taken into account when constraining the terrestrial end-member in global calculation of terrestrially derived DOM in the world ocean.

scholarly journals Diapycnal dissolved organic matter supply into the upper Peruvian oxycline

2019 ◽  
Vol 16 (9) ◽  
pp. 2033-2047 ◽  
Author(s):  
Alexandra N. Loginova ◽  
Sören Thomsen ◽  
Marcus Dengler ◽  
Jan Lüdke ◽  
Anja Engel
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
World Ocean ◽  
South Pacific ◽  
Solute Concentration ◽  
High Productivity ◽  
Upwelling System ◽  
The North ◽  
The World ◽  
O2 Supply

Abstract. The eastern tropical South Pacific (ETSP) hosts the Peruvian upwelling system, which represents one of the most productive areas in the world ocean. High primary production followed by rapid heterotrophic utilization of organic matter supports the formation of one of the most intense oxygen minimum zones (OMZs) in the world ocean, where dissolved oxygen (O2) concentrations reach less than 1 µmol kg−1. The high productivity leads to an accumulation of dissolved organic matter (DOM) in the surface layers that may serve as a substrate for heterotrophic respiration. However, the importance of DOM utilization for O2 respiration in the Peruvian upwelling system in general and for shaping the upper oxycline in particular remains unclear so far. This study reports the first estimates of diapycnal fluxes and supply of O2, dissolved organic carbon (DOC), dissolved organic nitrogen, dissolved hydrolysable amino acids (DHAA) and dissolved combined carbohydrates (DCCHO) for the ETSP off Peru. Diapycnal flux and supply estimates were obtained by combining measured vertical diffusivities and solute concentration gradients. They were analysed together with the molecular composition of DCCHO and DHAA to infer the transport of labile DOM into the upper OMZ and the potential role of DOM utilization for the attenuation of the diapycnal O2 flux that ventilates the OMZ. The observed diapycnal O2 flux (50 mmol O2 m−2 d−1 at maximum) was limited to the upper 80 m of the water column; the O2 supply of ∼1 µmol kg−1 d−1 was comparable to previously published O2 consumption rates for the North and South Pacific OMZs. The diapycnal DOM flux (31 mmol C m−2 d−1 at maximum) was limited to ∼30 m water depth, suggesting that the labile DOM is extensively consumed within the upper part of the shallow oxycline off Peru. The analyses of DCCHO and DHAA composition support this finding, suggesting that DOM undergoes comprehensive remineralization within the upper part of the oxycline, as the DOM within the core of the OMZ was found to be largely altered. Estimated by a simple equation for carbon combustion, aerobic respiration of DCCHO and DHAA, supplied by diapycnal mixing (0.46 µmol kg−1 d−1 at maximum), could account for up to 38 % of the diapycnal O2 supply in the upper oxycline, which suggests that DOM utilization plays a significant role for shaping the upper oxycline in the ETSP.

Organic matter of the World Ocean

2009 ◽  
Vol 50 (4) ◽  
pp. 299-307 ◽  
Author(s):  
E.A. Romankevich ◽  
A.A. Vetrov ◽  
V.I. Peresypkin
Keyword(s):  
Organic Matter ◽  
World Ocean ◽  
The World

scholarly journals Diapycnal dissolved organic matter supply into the upper Peruvian oxycline

2018 ◽  
Author(s):  
Alexandra N. Loginova ◽  
Sören Thomsen ◽  
Marcus Dengler ◽  
Jan Lüdke ◽  
Anja Engel
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
World Ocean ◽  
South Pacific ◽  
High Productivity ◽  
The Core ◽  
The North ◽  
The World ◽  
Consumption Rates ◽  
O2 Supply

Abstract. The Eastern Tropical South Pacific (ETSP) hosts the Peruvian upwelling system, which represents one of the most productive areas in the world ocean. High primary production followed by rapid heterotrophic utilization of organic matter supports the formation of one of the most intense oxygen minimum zones (OMZ) in the world ocean where dissolved oxygen (O2) concentrations reach well below 1 µmol kg−1. The high productivity leads to an accumulation of dissolved organic matter (DOM) in the surface layers that may serve as a substrate for heterotrophic respiration. However, the importance of DOM utilization for O2 respiration within the Peruvian OMZ remains unclear so far. Here, we evaluate the diapycnal fluxes of O2, dissolved organic carbon (DOC), dissolved organic nitrogen, dissolved hydrolysable amino acids (DHAA) and dissolved combined carbohydrates (DCCHO) and the composition of DOM in the ETSP off Peru to learn, whether labile DOM is reaching into the core of the OMZ and how important DOM utilization might be for O2 attenuation. The observed diapycnal 2 flux (50 mmol O2 m−2 day−1 at max) was limited to the upper 80 m of the water column, the flux attenuation of ~1 µmol L−1day−1, was comparable to previously published O2 consumption rates for the North and South Pacific OMZs. The diapycnal DOM flux (31 mmol C m−2 day−1 at max) was limited to ~30 m water depth, suggesting that the labile DOM is already utilized within the upper part of the shallow oxycline off Peru. The analyses of DCCHO and DHAA composition support this finding, suggesting that DOM undergoes comprehensive remineralization already within the upper part of the oxycline, as the DOM within the core of the OMZ was found to be largely altered. Estimated by a simple equation for carbon combustion, aerobic respiration of DCCHO and DHAA, supplied by diapycnal mixing (0.46 µmol L−1 day−1 at max), could account for up to 38 % of the diapycnal O2 supply in the upper oxycline, which suggests that DOM utilization may play a significant role for shape of the upper Peruvian oxycline.

Kazakhstan’s Economic Growth in the Context of the World Economy

2006 ◽  
pp. 133-146 ◽  
Author(s):  
K. Arystanbekov
Keyword(s):  
Economic Growth ◽  
Economic Policy ◽  
World Economy ◽  
World Ocean ◽  
Direct Access ◽  
Crude Petroleum ◽  
Nation States ◽  
The World ◽  
The Relationship

Kazakhstan’s economic policy results in 1995-2005 are considered in the article. In particular, the analysis of the relationship between economic growth and some indicators of nation states - population, territory, direct access to the World Ocean, and extraction of crude petroleum - is presented. Basic problems in the sphere of economic policy in Kazakhstan are formulated.

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