Autotrophic Carbon Fixation Pathways Along the Redox Gradient in Oxygen‐Depleted Oceanic Waters
"Anoxic marine zones (AMZs), also known as ‘oxygen‐deficient zones’, contribute to the loss of fixed nitrogen from the ocean by anaerobic microbial processes. While these microbial processes associated with the nitrogen cycle have been extensively studied, those linked to the carbon cycle in AMZs have received much less attention, particularly the autotrophic carbon fixation —a crucial component of the carbon cycle. [...]"
Source: Environmental Microbiology Reports
Authors: Paula Ruiz‐Fernández et al.
Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate
"The deep-ocean carbon cycle, especially carbon sequestration and outgassing, is one of the mechanisms to explain variations in atmospheric CO2 concentrations on millennial and orbital timescales. However, the potential role of subtropical North Pacific subsurface waters in modulating atmospheric CO2 levels on millennial timescales is poorly constrained. An increase in the respired CO2 concentration in the glacial deep-ocean due to biological pump generally corresponds to deoxygenation in the ocean interior. [...]"
Source: Climate of the Past
Authors: Jianjun Zou et al.
Implications of different nitrogen input sources for potential production and carbon flux estimates in the coastal Gulf of Mexico (GOM)
and Korean Peninsula coastal waters
"The coastal Gulf of Mexico (GOM) and coastal sea off the Korean Peninsula (CSK) both suffer from human-induced eutrophication. We used a nitrogen (N) mass balance model in two different regions with different nitrogen input sources to estimate organic carbon fluxes and predict future carbon fluxes under different model scenarios. The coastal GOM receives nitrogen predominantly from the Mississippi and Atchafalaya rivers and atmospheric nitrogen deposition is only a minor component in this region. [...]"
Source: Ocean Science
Authors: Jongsun Kim et al.
Oceanic organic carbon as a possible first-order control on the carbon cycle during the Bathonian–Callovian
"Oceans are the largest, readily exchangeable, superficial carbon reservoir; a current challenge in investigating past and present environments and predict future evolution relates to the role of oceanic carbon in regulating Earths' carbon cycle and climate. At least one paired δ13Ccarb-TOC decoupling event is noted in the Late Bathonian–Early Callovian. [...]"
Source: Global and Planetary Change
Authors: Ricardo L.Silva et al.
Constraining the Oceanic Uptake and Fluxes of Greenhouse Gases by Building an Ocean Network of Certified Stations:
The Ocean Component of the Integrated Carbon Observation System, ICOS-Oceans
"The European Research Infrastructure Consortium “Integrated Carbon Observation System” (ICOS) aims at delivering high quality greenhouse gas (GHG) observations and derived data products (e.g., regional GHG-flux maps) for constraining the GHG balance on a European level, on a sustained long-term basis. The marine domain (ICOS-Oceans) currently consists of 11 Ship of Opportunity lines (SOOP – Ship of Opportunity Program) and 10 Fixed Ocean Stations (FOSs) spread across European waters, including the North Atlantic and Arctic Oceans and the Barents, North, Baltic, and Mediterranean Seas. [...]"
Source: Frontiers in Marine Science
Authors: Tobias Steinhoff et al.
Anoxygenic photosynthesis and the delayed oxygenation of Earth’s atmosphere
"The emergence of oxygenic photosynthesis created a new niche with dramatic potential to transform energy flow through Earth’s biosphere. However, more primitive forms of photosynthesis that fix CO2 into biomass using electrons from reduced species like Fe(II) and H2 instead of water would have competed with Earth’s early oxygenic biosphere for essential nutrients. [...]"
Source: Nature Communications
Authors: Kazumi Ozaki et al.
Multi-faceted particle pumps drive carbon sequestration in the ocean
"The ocean’s ability to sequester carbon away from the atmosphere exerts an important control on global climate. The biological pump drives carbon storage in the deep ocean and is thought to function via gravitational settling of organic particles from surface waters. However, the settling flux alone is often insufficient to balance mesopelagic carbon budgets or to meet the demands of subsurface biota. [...]"
Authors: Philip W. Boyd et al.
Organic carbon recycling in Baltic Sea sediments – An integrated estimate on the system scale based on in situ measurements
"In situ measured benthic fluxes of dissolved inorganic carbon (DIC), a proxy for organic carbon (OC) oxidation or recycling rates, are used together with burial rates based on measured sediment accumulation rates (SAR) and vertical distribution of OC in the sediment solid phase to construct a benthic OC budget for the Baltic Sea system. [...]"
Source: Marine Chemistry
Authors: Madeleine M. Nilsson et al.
Carbon cycling in the North American coastal ocean: a synthesis
"A quantification of carbon fluxes in the coastal ocean and across its boundaries with the atmosphere, land, and the open ocean is important for assessing the current state and projecting future trends in ocean carbon uptake and coastal ocean acidification, but this is currently a missing component of global carbon budgeting. This synthesis reviews recent progress in characterizing these carbon fluxes for the North American coastal ocean. [...]"
Authors: Katja Fennel et al.
Phytoplankton calcifiers control nitrate cycling and the pace of transition in warming icehouse and cooling greenhouse climates
"Phytoplankton calcifiers contribute to global carbon cycling through their dual formation of calcium carbonate and particulate organic carbon (POC). The carbonate might provide an efficient export pathway for the associated POC to the deep ocean, reducing the particles' exposure to biological degradation in the upper ocean and increasing the particle settling rate. Previous work has suggested ballasting of POC by carbonate might increase in a warming climate, in spite of increasing carbonate dissolution rates, because calcifiers benefit from the widespread nutrient limitation arising from stratification. [...]"
Authors: Karin F. Kvale et al.