Bibliografías temáticas / Carbon biological pump

Literatura académica sobre el tema "Carbon biological pump"

Autor: Grafiati

Publicado: 20 de abril de 2024

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Artículos de revistas sobre el tema "Carbon biological pump"

Silkin, Vladimir A., Oleg I. Podymov y Anna V. Lifanchuk. "Biological carbon pump in the Black Sea". Hydrosphere Еcology (Экология гидросферы), n.º 2(8) (diciembre de 2022): 69–92. http://dx.doi.org/10.33624/2587-9367-2022-2(8)-69-92.

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In the northeastern part of the Black Sea, the biological carbon pump is represented by both organic and carbonate pumps. The organic carbon pump consists of small-cell diatoms (mainly Pseudo-nitzschia pseudodelicatissima) and large-cell diatoms (Pseudosolenia calcar-avis and Proboscia alata). The carbonate pump is represented by only one species of cococcolithophore, Emiliania huxleyi. These species form intense blooms that require characteristic hydrological and hydrochemical conditions. The seasonal dynamics of the biological carbon pump is as follows: organic pump (spring) → carbonate pump (late spring and early summer) → organic pump (summer and autumn). An exception is the long-term dynamics of carbon concentration, and no significant carbon growth trends have been identified. During the intensification of the work of the carbonate pump, partial concentrations of carbon in water, increased relative to the atmosphere, and an increased influence of the organic pump on high partial pressure are released. In late spring and early summer, CO2 is released in the Black Sea, as a result, absorption increases in summer. The carbonate pump arises with a greater arrival at sea.

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Pautova, Larisa A. y Vladimir A. Silkin. "Biological carbon pump in the ocean and phytoplankton structure". Hydrosphere Еcology (Экология гидросферы), n.º 1(3) (2019): 1–12. http://dx.doi.org/10.33624/2587-9367-2019-1(3)-1-12.

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The process of carbon transfer from the atmosphere to the ocean floor is determined by three different pumps in nature: a solubility pump, an organic pump and a carbonate pump. The latter two are of biological nature. Phytoplankton is a key mediator of organic and carbonate pumps. Depending on its structure, either an organic pump or a carbonate pump will dominate. The structure of the phytoplankton community is formed depending on the hydrophysical and hydrochemical conditions in the ocean. An important regulator of a biological carbon pump is the intensity of the processes in the carbon cycle, operating in the photic zone. The degree of closure of this cycle depends on the structure of the food chain. The increasing complexity of the food chain by adding organisms of high trophic levels reduces the efficiency of the carbon pump. Conversely, the simplification of such a structure increases the flow of organic carbon to the ocean floor.

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Hamme, Roberta C., David P. Nicholson, William J. Jenkins y Steven R. Emerson. "Using Noble Gases to Assess the Ocean's Carbon Pumps". Annual Review of Marine Science 11, n.º 1 (3 de enero de 2019): 75–103. http://dx.doi.org/10.1146/annurev-marine-121916-063604.

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Natural mechanisms in the ocean, both physical and biological, concentrate carbon in the deep ocean, resulting in lower atmospheric carbon dioxide. The signals of these carbon pumps overlap to create the observed carbon distribution in the ocean, making the individual impact of each pump difficult to disentangle. Noble gases have the potential to directly quantify the physical carbon solubility pump and to indirectly improve estimates of the biological organic carbon pump. Noble gases are biologically inert, can be precisely measured, and span a range of physical properties. We present dissolved neon, argon, and krypton data spanning the Atlantic, Southern, Pacific, and Arctic Oceans. Comparisons between deep-ocean observations and models of varying complexity enable the rates of processes that control the carbon solubility pump to be quantified and thus provide an important metric for ocean model skill. Noble gases also provide a powerful means of assessing air–sea gas exchange parameterizations.

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Birch, Heather, Daniela N. Schmidt, Helen K. Coxall, Dick Kroon y Andy Ridgwell. "Ecosystem function after the K/Pg extinction: decoupling of marine carbon pump and diversity". Proceedings of the Royal Society B: Biological Sciences 288, n.º 1953 (23 de junio de 2021): 20210863. http://dx.doi.org/10.1098/rspb.2021.0863.

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The ocean biological pump is the mechanism by which carbon and nutrients are transported to depth. As such, the biological pump is critical in the partitioning of carbon dioxide between the ocean and atmosphere, and the rate at which that carbon can be sequestered through burial in marine sediments. How the structure and function of planktic ecosystems in the ocean govern the strength and efficiency of the biological pump and its resilience to disruption are poorly understood. The aftermath of the impact at the Cretaceous/Palaeogene (K/Pg) boundary provides an ideal opportunity to address these questions as both the biological pump and marine plankton size and diversity were fundamentally disrupted. The excellent fossil record of planktic foraminifera as indicators of pelagic-biotic recovery combined with carbon isotope records tracing biological pump behaviour, show that the recovery of ecological traits (diversity, size and photosymbiosis) occurred much later (approx. 4.3 Ma) than biological pump recovery (approx. 1.8 Ma). We interpret this decoupling of diversity and the biological pump as an indication that ecosystem function had sufficiently recovered to drive an effective biological pump, at least regionally in the South Atlantic.

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Ödalen, Malin, Jonas Nycander, Kevin I. C. Oliver, Laurent Brodeau y Andy Ridgwell. "The influence of the ocean circulation state on ocean carbon storage and CO<sub>2</sub> drawdown potential in an Earth system model". Biogeosciences 15, n.º 5 (6 de marzo de 2018): 1367–93. http://dx.doi.org/10.5194/bg-15-1367-2018.

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Abstract. During the four most recent glacial cycles, atmospheric CO2 during glacial maxima has been lowered by about 90–100 ppm with respect to interglacials. There is widespread consensus that most of this carbon was partitioned in the ocean. It is, however, still debated which processes were dominant in achieving this increased carbon storage. In this paper, we use an Earth system model of intermediate complexity to explore the sensitivity of ocean carbon storage to ocean circulation state. We carry out a set of simulations in which we run the model to pre-industrial equilibrium, but in which we achieve different states of ocean circulation by changing forcing parameters such as wind stress, ocean diffusivity and atmospheric heat diffusivity. As a consequence, the ensemble members also have different ocean carbon reservoirs, global ocean average temperatures, biological pump efficiencies and conditions for air–sea CO2 disequilibrium. We analyse changes in total ocean carbon storage and separate it into contributions by the solubility pump, the biological pump and the CO2 disequilibrium component. We also relate these contributions to differences in the strength of the ocean overturning circulation. Depending on which ocean forcing parameter is tuned, the origin of the change in carbon storage is different. When wind stress or ocean diapycnal diffusivity is changed, the response of the biological pump gives the most important effect on ocean carbon storage, whereas when atmospheric heat diffusivity or ocean isopycnal diffusivity is changed, the solubility pump and the disequilibrium component are also important and sometimes dominant. Despite this complexity, we obtain a negative linear relationship between total ocean carbon and the combined strength of the northern and southern overturning cells. This relationship is robust to different reservoirs dominating the response to different forcing mechanisms. Finally, we conduct a drawdown experiment in which we investigate the capacity for increased carbon storage by artificially maximising the efficiency of the biological pump in our ensemble members. We conclude that different initial states for an ocean model result in different capacities for ocean carbon storage due to differences in the ocean circulation state and the origin of the carbon in the initial ocean carbon reservoir. This could explain why it is difficult to achieve comparable responses of the ocean carbon pumps in model inter-comparison studies in which the initial states vary between models. We show that this effect of the initial state is quantifiable. The drawdown experiment highlights the importance of the strength of the biological pump in the control state for model studies of increased biological efficiency.

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Jónasdóttir, Sigrún Huld, André W. Visser, Katherine Richardson y Michael R. Heath. "Seasonal copepod lipid pump promotes carbon sequestration in the deep North Atlantic". Proceedings of the National Academy of Sciences 112, n.º 39 (3 de septiembre de 2015): 12122–26. http://dx.doi.org/10.1073/pnas.1512110112.

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Estimates of carbon flux to the deep oceans are essential for our understanding of global carbon budgets. Sinking of detrital material (“biological pump”) is usually thought to be the main biological component of this flux. Here, we identify an additional biological mechanism, the seasonal “lipid pump,” which is highly efficient at sequestering carbon into the deep ocean. It involves the vertical transport and metabolism of carbon rich lipids by overwintering zooplankton. We show that one species, the copepod Calanus finmarchicus overwintering in the North Atlantic, sequesters an amount of carbon equivalent to the sinking flux of detrital material. The efficiency of the lipid pump derives from a near-complete decoupling between nutrient and carbon cycling—a “lipid shunt,” and its direct transport of carbon through the mesopelagic zone to below the permanent thermocline with very little attenuation. Inclusion of the lipid pump almost doubles the previous estimates of deep-ocean carbon sequestration by biological processes in the North Atlantic.

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Ducklow, Hugh, Deborah Steinberg y Ken Buesseler. "Upper Ocean Carbon Export and the Biological Pump". Oceanography 14, n.º 4 (2001): 50–58. http://dx.doi.org/10.5670/oceanog.2001.06.

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Bishop, James. "Autonomous Observations of the Ocean Biological Carbon Pump". Oceanography 22, n.º 2 (1 de junio de 2009): 182–93. http://dx.doi.org/10.5670/oceanog.2009.48.

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Sanders, Richard, Stephanie A. Henson, Marja Koski, Christina L. De La Rocha, Stuart C. Painter, Alex J. Poulton, Jennifer Riley et al. "The Biological Carbon Pump in the North Atlantic". Progress in Oceanography 129 (diciembre de 2014): 200–218. http://dx.doi.org/10.1016/j.pocean.2014.05.005.

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Pinti, Jérôme, Tim DeVries, Tommy Norin, Camila Serra-Pompei, Roland Proud, David A. Siegel, Thomas Kiørboe et al. "Model estimates of metazoans' contributions to the biological carbon pump". Biogeosciences 20, n.º 5 (14 de marzo de 2023): 997–1009. http://dx.doi.org/10.5194/bg-20-997-2023.

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Abstract. The daily vertical migrations of fish and other metazoans actively transport organic carbon from the ocean surface to depth, contributing to the biological carbon pump. We use an oxygen-constrained, game-theoretic food-web model to simulate diel vertical migrations and estimate near-global (global ocean minus coastal areas and high latitudes) carbon fluxes and sequestration by fish and zooplankton due to respiration, fecal pellets, and deadfalls. Our model provides estimates of the carbon export and sequestration potential for a range of pelagic functional groups, despite uncertain biomass estimates of some functional groups. While the export production of metazoans and fish is modest (∼20 % of global total), we estimate that their contribution to carbon sequestered by the biological pump (∼800 PgC) is conservatively more than 50 % of the estimated global total (∼1300 PgC) and that they have a significantly longer sequestration timescale (∼250 years) than previously reported for other components of the biological pump. Fish and multicellular zooplankton contribute about equally to this sequestered carbon pool. This essential ecosystem service could be at risk from both unregulated fishing on the high seas and ocean deoxygenation due to climate change.

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Tesis sobre el tema "Carbon biological pump"

Smith, Helen E. K. "The contribution of mineralising phytoplankton to the biological carbon pump in high latitudes". Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/376448/.

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The biological carbon pump (BCP) exports 5 - 12 Gt C yr−1 to the deep sea and is important for the distribution of carbon within the ocean. Previous studies proposed that the phytoplankton community structure and availability of dense biominerals are key in defining regional export. This thesis examines these factors and their influence on export in the Southern Ocean and the Arctic through the examination of upper ocean species composition, distribution and marine snow particles. In the Southern Ocean, the samples were collected from the high reflectance feature known as the Great Calcite Belt (GCB). The marine snow catcher was used to capture sinking particles and allowed the examination of both the large, fast sinking particles and the slow sinking fraction of particulate organic carbon (POC). The GCB was dominated by nanophytoplankton (<20μm), where the coccolithophore Emiliania huxleyi and diatoms Fragilariopsis nana, Fragilariopsis pseudonana and Pseudonitzschia sp. were the dominant species driving the variation in biogeography. The variation in biogeography was best described by a combination of temperature, nutrients and pCO2. E. huxleyi forms distinct features in the GCB on the Patagonian Shelf, near South Georgia and the Crozet Islands. A southwards progression of E. huxleyi occurs within High Nutrient Low Silica Low Chlorophyll waters in post-bloom conditions after silicic acid and iron drawdown by diatoms. When examined in terms of biomass, the diatoms dominate the GCB, although E. huxleyi was the single biggest contributor as a species. A statistical comparison of surface species and slow sinking material indicated that there was a degree of similarity between the surface and exported community but was regionally variable. Coccolithophores and diatoms contributed minimally (<10%) to upper ocean biomass and total carbon export. The results of this thesis indicate that even though the coccolithophores and diatoms are important phytoplankton for primary production, their direct contribution as cells to carbon export is low. POC flux correlated with opal flux but not calcite flux indicating that the opal was more important in driving POC flux in the GCB. Two types of sinking particles were examined, marine snow aggregates and faecal pellets and there was no significant difference between the sinking velocities. Marine snow sinking velocity was not dependent on size of the aggregate. The concentrations of biominerals and POC in the surface waters and the biominerals in the sinking particles did not influence the sinking velocity. This indicates that porosity and POC content could be more important in determining the sinking velocity and the carbon flux. The synthesis includes the species composition and biomass of the Arctic, which displayed similar trends to the GCB. The results from this thesis suggest that the slow sinking carbon export may not be significantly affected by potential changes in upper ocean biomineralising phytoplankton community structure and upper ocean chemistry. The effects of porosity and POC contents of the particles are here considered to be just as important for determining the export flux than upper ocean community structure and biomineral ballast availability. This implies that the impacts of ocean acidification will become more important deeper in the water column as biominerals become more important within sinking particles as POC is removed.

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Giering, Sarah L. C. "The role of mesozooplankton in the biological carbon pump of the North Atlantic". Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/359058/.

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Cooper, Rachel. "OCEAN ACIDIFICATION: UNDERSTANDING THE COASTAL CARBON PUMP IN A HIGH CO2 WORLD". VCU Scholars Compass, 2012. http://scholarscompass.vcu.edu/etd/420.

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Since the 1800s, carbon dioxide emissions due to human activities have contributed significantly to the amount of carbon in the atmosphere. Approximately a third of this carbon is absorbed by the ocean, through air-sea fluxes at the ocean surface (Sabine, 2004). Increased CO2 has changed the carbon chemistry of the ocean and hence the pH. pH is expected to drop by 0.4 by the year 2100. It is unclear how this lower pH will affect carbon cycling and sequestration with respect to the biological carbon pump. Most studies have focused on open ocean phytoplankton or bacterial communities in large, stationary mesocosms. Few studies have coupled both phytoplankton and bacterial processes and even fewer have investigated coastal communities, where pH and pCO2 can vary drastically. This study focused first on developing and evaluating a mesocosm and alternative method for elevating pCO2. The second goal was to determine how potential changes in phytoplankton DOC release and community structure and the resulting carbon pool may affect bacterial secondary production and ectoenzyme activity in a natural coastal community. Mesocosms aimed to mimic natural pCO2 fluctuations by maintaining CO2 concentration of 1250 ppm in the headspace, as aqueous pCO2 may change with biological processes. Six mesocosms were filled with 40L of water from the Chesapeake Bay (three ambient pCO2 and three 1250 ppm) and monitored over 15 days. Chlorophyll a, DOC, bacterial respiration, bacterial production, and enzyme activity were measured. Bacterial production and respiration were used to calculate bacterial growth efficiency (BGE). Results showed that there was no significant difference between the ambient and elevated groups with respect to chlorophyll a, DOC, BGE and enzymes activity. However, differences in bacterial respiration and bacterial production during the first four days of the experiment may suggest that bacteria require time to acclimate to elevated pCO2. Phytoplankton and bacteria in coastal areas are exposed to a wide range of abiotic factors such as seasonal temperature variations, salinity, mixing, and terrestrial inputs. The pH of the Chesapeake Bay ranges between 7.5 and 8.3, and it is possible that the phytoplankton and bacteria are adapted to cope with a wide range of pH (Wong, 2012). This study suggests that the biological carbon pump may not be significantly altered in our future ocean.

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Walker, Stevie. "Climate change impacts on the ocean’s biological carbon pump in a CMIP6 Earth System Model:". Thesis, Boston College, 2021. http://hdl.handle.net/2345/bc-ir:109224.

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Thesis advisor: Hilary Palevsky
The ocean plays a key role in global carbon cycling, taking up CO2 from the atmosphere. A fraction of this CO2 is converted into organic carbon through primary production in the surface ocean and sequestered in the deep ocean through a process known as the biological pump. The ability of the biological pump to sequester carbon away from the atmosphere is influenced by the interaction between the annual cycle of ocean mixed layer depth (MLD), primary production, and ecosystem processes that influence export efficiency. Gravitational sinking of particulate organic carbon (POC) is the largest component of the biological pump and the aspect that is best represented in Earth System Models (ESMs). I use ESM data from CESM2, an ESM participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6), to investigate how a high-emissions climate change scenario will impact POC flux globally and regionally over the 21st century. The model simulates a 4.4% decrease in global POC flux at the 100 m depth horizon, from 7.12 Pg C/yr in the short-term (2014-2034) to 6.81 Pg C/yr in the long-term (2079-2099), indicating that the biological pump will become less efficient overall at sequestering carbon. However, the extent of change varies across the globe, including the largest POC flux declines in the North Atlantic, where the maximum annual MLD is projected to shoal immensely. In the future, a multi-model comparison across ESMs will allow for further analysis on the variability of these changes to the biological pump
Thesis (BS) — Boston College, 2021
Submitted to: Boston College. College of Arts and Sciences
Discipline: Departmental Honors
Discipline: Earth and Environmental Science

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Duret, Manon. "Microbial communities in sinking and suspended particles and their influence on the oceanic biological carbon pump". Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/427041/.

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Export of photosynthetically produced organic matter, from the sunlit to the dark ocean, in the form of sinking particles represents the major mechanism of the biological carbon pump that removes CO2 from the atmosphere. Most of the organic matter bound in sinking particles undergoes microbial remineralisation while traversing the water column, thereby causing CO2 and inorganic nutrients to be released. Increasing evidence indicates that most remineralisation does not occur directly on sinking particles, but rather on suspended particles and dissolved organic matter resulting from their disaggregation and solubilisation. Most particulate organic carbon in the mesopelagic ocean is bound to suspended particles, which represent a major substrate for heterotrophic organisms. Despite their crucial importance, suspended particles and their associated microbial communities have been largely overlooked in favour to sinking particles. This thesis presents the first comparison of diversity and functionalities between microbial communities associated with suspended and sinking particles. Using amplicon sequencing of small-subunit ribosomal RNA genes on particles collected with a marine snow catcher deployed in the Southern Ocean, this thesis demonstrates that prokaryotic communities associated with suspended and sinking particles differ significantly. Particle-associated remineralising bacteria showed a clear preference for either particle-type likely relating to differential organic matter composition. Suspended particles from the upper-mesopelagic were predominately composed of prymnesiophytes and soft-tissue animals, while more efficient carbon export from diatoms was indicated by their prevalence in sinking particles. Eukaryotic sequences associated with suspended and sinking particles were largely dominated by heterotrophic protists, highlighting their major contribution to particulate organic matter remineralisation in the upper-mesopelagic. Finally, remineralisation activities, as well as nitrogen and sulphur cycling, were investigated by comparing metatranscriptomes of various particle-types collected in the North Atlantic. Free-living, small sinking and small suspended particle-associated microbes appeared most active in the remineralisation of simple organic compounds, while large suspended particles acted as the main venue of complex organic matter remineralisation. Additionally, actively expressed genes related to anaerobic processes in small particles corroborate recent postulations that marine particles may serve as oxygen-deficient microniches, and hence, may be key to redox cycling of elements in the ocean. Overall, this dissertation highlights differences between suspended and sinking particles as well as their potential biogeochemical implications in the ocean and provides further insights into constraints shaping the oceanic biological carbon pump.

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Stange, Paul [Verfasser]. "The inﬂuence of plankton food-web structure on the efficiency of the biological carbon pump / Paul Stange". Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/1142154777/34.

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Dumont, Isabelle. "Interactions between the microbial network and the organic matter in the Southern Ocean: impacts on the biological carbon pump". Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210300.

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The Southern Ocean (ca. 20% of the world ocean surface) is a key place for the regulation of Earth climate thanks to its capacity to absorb atmospheric carbon dioxide (CO2) by physico-chemical and biological mechanisms. The biological carbon pump is a major pathway of absorption of CO2 through which the CO2 incorporated into autotrophic microorganisms in surface waters is transferred to deep waters. This process is influenced by the extent of the primary production and by the intensity of the remineralization of organic matter along the water column. So, the annual cycle of sea ice, through its in situ production and remineralization processes but also, through the release of microorganisms, organic and inorganic nutrients (in particular iron)into the ocean has an impact on the carbon cycle of the Southern Ocean, notably by promoting the initiation of phytoplanktonic blooms at time of ice melting.

The present work focussed on the distribution of organic matter (OM) and its interactions with the microbial network (algae, bacteria and protozoa) in sea ice and ocean, with a special attention to the factors which regulate the biological carbon pump of the Southern Ocean. This thesis gathers data collected from a) late winter to summer in the Western Pacific sector, Western Weddell Sea and Bellingshausen Sea during three sea ice cruises ARISE, ISPOL-drifting station and SIMBA-drifting station and b) summer in the Sub-Antarctic and Polar Front Zone during the oceanographic cruise SAZ-Sense.

The sea ice covers were typical of first-year pack ice with thickness ranging between 0.3 and 1.2 m, and composed of granular and columnar ice. Sea ice temperature ranging between -8.9°C and -0.4°C, brines volume ranging between 2.9 to 28.2% and brines salinity from 10 to >100 were observed. These extreme physicochemical factors experienced by the microorganisms trapped into the semi-solid sea ice matrix therefore constitute an extreme change as compared to the open ocean. Sea ice algae were mainly composed of diatoms but autotrophic flagellates (such as dinoflagellates or Phaeocystis sp.) were also typically found in surface ice layers. Maximal algal biomass was usually observed in the bottom ice layers except during SIMBA where the maxima was localised in the top ice layers likely because of the snow and ice thickness which limit the light available in the ice cover. During early spring, the algal growth was controlled by the space availability (i.e. brine volume) while in spring/summer (ISPOL, SIMBA) the major nutrients availability inside sea ice may have controlled algal growth. At all seasons, high concentrations of dissolved and particulate organic matter were measured in sea ice as compared to the water column. Dissolved monomers (saccharides and amino acids) were accumulated in sea ice, in particular in winter. During spring and summer, polysaccharides constitute the main fraction of the dissolved saccharides pool. High concentrations of transparent exopolymeric particles (TEP), mainly constituted with saccharides, were present and their gel properties greatly influence the internal habitat of sea ice, by retaining the nutrients and by preventing the protozoa grazing pressure, inducing therefore an algal accumulation. The composition as well as the vertical distribution of OM in sea ice was linked to sea ice algae.

Besides, the distribution of microorganisms and organic compounds in the sea ice was also greatly influenced by the thermodynamics of the sea ice cover, as evidenced during a melting period for ISPOL and during a floodfreeze cycle for SIMBA. The bacteria distribution in the sea ice was not correlated with those of algae and organic matter. Indeed, the utilization of the accumulated organic matter by bacteria seemed to be limited by an external factor such as temperature, salinity or toxins rather than by the nature of the organic substrates, which are partly composed of labile monomeric saccharides. Thus the disconnection of the microbial loop leading to the OM accumulation was highlighted in sea ice.

In addition the biofilm formed by TEP was also involved in the retention of cells and other compounds(DOM, POM, and inorganic nutrients such as phosphate and iron) to the brine channels walls and thus in the timing of release of ice constituents when ice melts. The sequence of release in marginal ice zone, as studied in a microcosm experiments realized in controlled and trace-metal clean conditions, was likely favourable to the development of blooms in the marginal ice zone. Moreover microorganisms derived from sea ice (mainly <10 µm) seems able to thrive and grow in the water column as also the supply of organic nutrients and Fe seems to benefit to the pelagic microbial community.

Finally, the influence of the remineralization of organic matter by heterotrophic bacterioplankton on carbon export and biological carbon pump efficiency was investigated in the epipelagic (0-100 m) and mesopelagic(100-700 m) zones during the summer in the sub-Antarctic and Polar Front zones (SAZ and PFZ) of the Australian sector (Southern Ocean). Opposite to sea ice, bacterial biomass and activities followed Chl a and organic matter distributions. Bacterial abundance, biomass and activities drastically decreased below depths of 100-200 m. Nevertheless, depth-integrated rates through the thickness of the different water masses showed that the mesopelagic contribution of bacteria represents a non-negligible fraction, in particular in a diatom-dominated system./

L’océan Antarctique (± 20% de la surface totale des océans) est un endroit essentiel pour la régulation du climat de notre planète grâce à sa capacité d’absorber le dioxyde de carbone (CO2) atmosphérique par des mécanismes physico-chimique et biologique. La pompe biologique à carbone est un processus majeur de fixation de CO2 par les organismes autotrophes à la surface de l’océan et de transfert de carbone organique vers le fond de l’océan. Ce processus est influencé par l’importance de la production primaire ainsi que par l’intensité de la reminéralisation de la matière organique dans la colonne d’eau. Ainsi, le cycle annuel de la glace via sa production/reminéralisation in situ mais aussi via l’ensemencement de l’océan avec des microorganismes et des nutriments organiques et inorganiques (en particulier le fer) a un impact sur le cycle du carbone dans l’Océan Antarctique, notamment en favorisant l’initiation d’efflorescences phytoplanctoniques dans la zone marginale de glace.

Plus précisément, nous avons étudié les interactions entre le réseau microbien (algues, bactéries et protozoaires) et la matière organique dans le but d’évaluer leurs impacts potentiels sur la pompe biologique de carbone dans l’Océan Austral. Deux écosystèmes différents ont été étudiés :la glace de mer et le milieu océanique grâce à des échantillons prélevés lors des campagnes de glace ARISE, ISPOL et SIMBA et lors de la campagne océanographique SAZ-Sense, couvrant une période allant de la fin de l’hiver à l’été.

La glace de mer est un environnement très particulier dans lequel les microorganismes planctoniques se trouvent piégés lors de la formation de la banquise et dans lesquels ils subissent des conditions extrêmes de température et de salinité, notamment. Les banquises en océan ouvert étudiées (0,3 à 1,2 m d’épaisseur, températures de -8.9°C à -0.4°C, volumes relatifs de saumure de 2.9 à 28.2% et salinités de saumures entre 10 et jusque >100) étaient composées de glace columnaire et granulaire. Les algues de glace étaient principalement des diatomées mais des flagellés autotrophes (tels que des dinoflagellés ou Phaeocystis sp.) ont été typiquement observés dans les couches de glace de surface. Les biomasses algales maximales se trouvaient généralement dans la couche de glace de fond sauf à SIMBA où les maxima se trouvaient en surface, probablement en raison de l’épaisseur des couches de neige et de glace, limitant la lumière disponible dans la colonne de glace. Au début du printemps, la croissance algale était contrôlée par l’espace disponible (càd le volume des saumures) tandis qu’au printemps/été, la disponibilité en nutriments majeurs a pu la contrôler. A toutes les saisons, des concentrations élevées en matière organique (MO) dissoute et particulaire on été mesurées dans la glace de mer par rapport à l’océan. Des monomères dissous (sucres et acides aminés) étaient accumulés dans la glace, surtout en hiver. Au printemps et été, les polysaccharides dissous dominaient le réservoir de sucres. La MO était présente sous forme de TEP qui par leurs propriétés de gel modifie l’habitat interne de la glace. Ce biofilm retient les nutriments et gêne le mouvement des microorganismes. La composition et la distribution de la MO dans la glace étaient en partie reliées aux algues de glace. De plus, la thermodynamique de la couverture de glace peut contrôler la distribution des microorganismes et de la MO, comme observé lors de la fonte de la glace à ISPOL et lors du refroidissement de la banquise à SIMBA. La distribution des bactéries n’est pas corrélée avec celle des algues et de la MO dans la glace. En effet, la consommation de la MO par les bactéries semble être limitée non pas par la nature chimique des substrats mais par un facteur extérieur affectant le métabolisme bactérien tel que la température, la salinité ou une toxine. Le dysfonctionnement de la boucle microbienne menant à l’accumulation de la MO dans la glace a donc été mis en évidence dans nos échantillons.

De plus, le biofilm formé par les TEP est aussi impliquée dans l’attachement des cellules et autres composés aux parois des canaux de saumure et donc dans la séquence de largage lors de la fonte. Cette séquence semble propice au développement d’efflorescences phytoplanctoniques dans la zone marginale de glace. Les microorganismes originaires de la glace (surtout ceux de taille < 10 μm) semblent capables de croître dans la colonne d’eau et l’apport en nutriments organiques et inorganiques apparaît favorable à la croissance des microorganismes pélagiques.

Enfin, l’influence des activités hétérotrophes sur l’export de carbone et l’efficacité de la pompe biologique à carbone a été évaluée dans la couche de surface (0-100 m) et mésopélagique (100-700 m) de l’océan. Au contraire de la glace, les biomasses et activités bactériennes suivaient les distributions de la chlorophyll a et de la MO. Elles diminuent fortement en dessous de 100-200 m, néanmoins les valeurs intégrées sur la hauteur de la colonne d’eau indiquent que la reminéralisation de la MO par les bactéries dans la zone mésopélagique est loin d’être négligeable, spécialement dans une région dominée par les diatomées.

Doctorat en Sciences agronomiques et ingénierie biologique
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Thiele, Stefan [Verfasser], Bernhard M. [Akademischer Betreuer] Fuchs, Rudolf [Akademischer Betreuer] Amann y Victor S. [Akademischer Betreuer] Smetacek. "The role of specific microbial communities in the biological carbon pump / Stefan Thiele. Gutachter: Rudolf Amann ; Victor S. Smetacek. Betreuer: Bernhard M. Fuchs". Bremen : Staats- und Universitätsbibliothek Bremen, 2013. http://d-nb.info/1072156121/34.

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Forrer, Heather. "Toward an improved understanding of the Southern Ocean's biological pump: phytoplankton group-specific contributions to nitrogen and carbon cycling across the Subantarctic Indian Ocean". Master's thesis, Faculty of Science, 2021. http://hdl.handle.net/11427/33675.

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Iron (and silicate) (co-)limitation of phytoplankton is considered a primary cause of the Southern Ocean's inefficient biological pump. However, the role of phytoplankton community structure and response to nutrient cycling remains poorly understood. In a mass balance sense, phytoplankton consumption of new nitrogen (N; e.g., allochthonous nitrate) is proportional to net carbon (C) export, while growth fueled by recycled N (e.g., ammonium) yields no net C flux. The N isotope ratio (δ15N) of surface biomass has long been used as an integrative tracer of new versus regenerated uptake. This approach is rendered more accurate by coupling either fluorescence-activated cell sorting (FACS; of nano- and picophytoplankton; 0.4-20 μm) or microscopy (for microphytoplankton; >20 um) with groupspecific δ15N measurements. Samples were collected for the analysis of nutrients and nitrate-, FACS-, and microscopy-δ15N on a mid-summer transect of the Subantarctic Indian basin during the 2016/17 Antarctic Circumnavigation Expedition (ACE) cruise. The data show that all phytoplankton populations preferentially utilize nitrate (≥55%) across the Indian Sector of the Subantarctic, potentially driving higher C export potential than previously estimated. Indeed, near the Subantarctic islands, 72% of microand >80% of nano- and picophytoplankton growth is supported by nitrate. This is likely due to the partial alleviation of phytoplankton iron and silicate stress, largely as a result of bathymetric upwelling, which constitutes a manifestation of the island mass effect. C export potential is lower in the open ocean region away from the islands where iron stress has been shown to be higher; here, nitrate supports >55% of micro- and picophytoplankton and 7 to 79% of nanophytoplankton growth. In terms of relative abundance (RA), the open Subantarctic is dominated by picoeukaryotes (64%), although there exists a large disconnect between relative abundance and potential contribution to C export. The three largest surface-ocean phytoplankton populations included in this study – microphytoplankton, cryptophytes, and nanoeukaryotes – each contribute ~30% to the total C export potential across the Subantarctic Indian sector while picophytoplankton contribute ~5%. Thus, as has been concluded previously, the larger phytoplankton size classes are disproportionately important drivers of the Subantarctic biological pump. Other interesting ecological findings include diatom-dominated microphytoplankton populations apparently fueled by a significant fraction of regenerated N, even in areas of iron supply, and Synechococcus relying near-exclusively on new N, in contrast to subtropical observations. Additionally, the abundance of Synechococcus appears to be controlled by the availability of iron across the Subantarctic, with silicate and temperature playing a supporting role.

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Ramondenc, Simon. "Analyse des variations spatio-temporelles du zooplancton gélatineux et son effet sur les flux de matières à l'aide d'une approche combinant expérimentation et écologie numérique". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066528/document.

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Le terme plancton désigne l'ensemble des organismes dérivant au grès des courants marins. On distingue le plancton végétal et principalement photosynthétique, "le phytoplancton", du plancton animal hétérotrophe, "le zooplancton". Au cours des dernières décennies, de nombreuses études ont documenté une croissance de l'abondance et de la distribution spatiale du zooplancton gélatineux à travers diverses régions. Même si le terme "gélification" des océans doit être utilisé avec beaucoup de précaution, des régions comme la mer Méditerranée montre une constante augmentation des méduses au cours de ces 40 dernières années. L'espèce Pelagia noctiluca (Forsskål, 1775) est considérée comme étant la méduse la plus abondante du bassin méditerranéen depuis les années 70. Du fait de leur présence massive dans cette région, il est primordial d'évaluer précisément l'impact de P. noctiluca à la fois sur les cycles biogéochimiques et sur la structuration des écosystèmes pélagiques. Pour cela, les deux processus majeurs de transfert de matière dans l'écosystème doivent être étudiés : la séquestration de carbone via la pompe biologique et le transfert de carbon au travers des réseaux trophiques. Cette thèse s'articule autour de trois axes majeurs: (i) réaliser un premier bilan de l'export de carbone organique particulaire (POCtotal) et dissous (DOC) en mer Méditerranée, (ii) construire un modèle écophysiologique de P. noctiluca pour déterminer la contribution de cette méduse à la pompe biologique, et (iii) évaluer le niveau trophique de P. noctiluca et son potentiel impact sur les niveaux trophiques inférieurs
The term “plankton” refers to all the organisms drifting in the water following the currents. Commonly, the vegetable autotrophic and mainly photosynthetic, “phytoplankton” is distinguished from the heterotrophic and animal “zooplankton”. In the last decades, many studies reported an increase in the abundances and spatial distributions of gelatinous zooplankton in many oceans. Even if the concept of “jellyfication of the oceans” needs to be used with caution, jellyfish populations show an increase in Mediterranean Sea over the last 40 years. The species Pelagia noctiluca (Forsskål, 1775) is considered as the most abundant jellyfish in the Mediterranean basin since the 70s. Due to its massive presence in this area, it is essential to evaluate precisely the impact of P. noctiluca on both biogeochemical cycles and pelagic ecosystem structure. Thus, the contribution of P. noctiluca to the two main factors regulating the biological carbon transfer in the oceans: carbon sequestration via the biological carbon pump and carbon transfer through trophic networks. This manuscript is divided in 3 main sections : (i) providing an initial budget of the particulate (POCtotal) and dissolved organic carbon (DOC) in the Mediterranean sea, (ii) building an ecophysiological model of P. noctiluca to estimate its contribution to the biological carbon pump, and (iii) assessing the trophic level of P. noctiluca and its potential impact on lower trophic levels

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Libros sobre el tema "Carbon biological pump"

Steinberg, Deborah. Zooplankton Biogeochemical Cycles. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780199233267.003.0006.

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The structure of planktonic communities profoundly affects particle export and sequestration of organic material (the biological pump) and the chemical cycling of nutrients. This chapter describes the integral and multifaceted role zooplankton (both protozoan and metazoan) play in the export and cycling of elements in the ocean, with an emphasis on the North Atlantic Ocean and adjacent seas. Zooplankton consume a significant proportion of primary production across the world's oceans, and their metabolism plays a key role in recycling carbon, nitrogen, and other elements. The chapter also addresses how human or climate-influenced changes in North Atlantic zooplankton populations may in turn drive changes in zooplankton-mediated biogeochemical cycling.

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Capítulos de libros sobre el tema "Carbon biological pump"

Rixen, Tim, Niko Lahajnar, Tarron Lamont, Rolf Koppelmann, Bettina Martin, Luisa Meiritz, Claire Siddiqui y Anja K. Van der Plas. "The Marine Carbon Footprint: Challenges in the Quantification of the CO2 Uptake by the Biological Carbon Pump in the Benguela Upwelling System". En Sustainability of Southern African Ecosystems under Global Change, 729–57. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-10948-5_25.

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AbstractQuantifying greenhouse gas (GHG) emissions is essential for mitigating global warming, and has become the task of individual countries assigned to the Paris agreement in the form of National Greenhouse Gas Inventory Reports (NIR). The NIR informs on GHG emissions and removals over national territory encompassing the 200-mile Exclusive Economic Zone (EEZ). However, apart from only a few countries, who have begun to report on coastal ecosystems, mostly mangroves, salt marshes, and seagrass meadows, the NIR does not cover or report on GHG sources and sinks of the 200-mile exclusive economic zone which, for Namibia and South Africa includes the Benguela Upwelling System (BUS). Based on our results, we estimated a CO2 uptake by the biological carbon pump of 18.5 ± 3.3 Tg C year−1 and 6.0 ± 5.0 Tg C year−1 for the Namibian and South African parts of the BUS, respectively. Even though it is assumed that the biological carbon pump already responds to global change and fisheries, uncertainties associated with estimates of the CO2 uptake by the biological carbon pump are still large and hamper a thorough quantification of human impacts on the biological carbon pump. Despite these uncertainties, it is suggested to include parameters such as preformed nutrient supply, carbon export rates, Redfield ratios, and CO2 concentrations measured at specific key sites into the NIR to stay focussed on the biological carbon pump and to support research addressing open questions, as well as to improve methods and observing concepts.

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Thingstad, T. Frede. "Microbial Processes and the Biological Carbon Pump". En Towards a Model of Ocean Biogeochemical Processes, 193–208. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-84602-1_9.

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Anderson, T. R. y I. J. Totterdell. "Modelling the Response of the Biological Pump to Climate Change". En The Ocean Carbon Cycle and Climate, 65–96. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2087-2_3.

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AGUSTI, S., J. I. GONZÁLEZ-GORDILLO, D. VAQUÉ, M. ESTRADA, M. I. CEREZO, G. SALAZAR, J. M. GASOL y C. M. DUARTE. "chapter 6 Ubiquitous Healthy Diatoms in the Deep Sea Confirm Deep Carbon Injection by the Biological Pump". En Climate Change and the Oceanic Carbon Cycle, 123–48. 3333 Mistwell Crescent, Oakville, ON L6L 0A2, Canada: Apple Academic Press, 2017. http://dx.doi.org/10.1201/9781315207490-7.

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Passow, Uta y Thomas Weber. "The biological carbon pump". En Reference Module in Earth Systems and Environmental Sciences. Elsevier, 2023. http://dx.doi.org/10.1016/b978-0-323-99762-1.00031-0.

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Kirchman, David L. "Carbon Pumps in the Oceans". En Microbes, 48–71. Oxford University PressNew York, 2024. http://dx.doi.org/10.1093/oso/9780197688564.003.0004.

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Abstract Climate change would be a lot worse if not for the carbon dioxide (and heat) taken up by the ocean via carbon pumps, the largest being the biological pump. Phytoplankton carbon is exported to deep waters by particles such as zooplankton fecal pellets, marine snow, and other aggregates and by dissolved organic carbon (DOC). As part of the microbial carbon pump, bacteria contribute to the formation of refractory DOC that is 6000 years old. As carbon dioxide increases in the ocean, another gas, dissolved oxygen, is decreasing. Oceanic deoxygenation is caused by warming seawater and by bacterial activity stimulated by global warming. The worry is that bacteria are using refractory DOC that had sequestered carbon away from the atmosphere for thousands of years. Even if climate change doesn’t alter the ocean’s contribution to carbon sequestration, it seems likely to disrupt microbial communities that are the base of life in the ocean.

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Dolman, Han. "The Carbon Cycle". En Biogeochemical Cycles and Climate, 129–58. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198779308.003.0009.

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The chapter first shows carbon dioxide variability over long geological timescales. The current stocks and fluxes of carbon are then given, for the whole planet and for the atmosphere, ocean and land separately. The main flows of carbon in the ocean, through the biological pump (via uptake through photosynthesis) and the physical pump (via involving chemical transformation uptake in water and production of carbonate), and on land, through photosynthesis (Gross Primary Production) and respiration leading to Net Primary Production, Net Ecosystem Production and Net Biome Production and through the storage of carbon in biomass, are described. Next, carbon interactions during the Paleocene–Eocene Thermal Maximum and glacial–interglacial transitions, thought to involve changes in ocean circulation and upwelling, are examined. The key changes from anthropogenic perturbation of the natural carbon cycle are shown to be due to fossil fuel burning and land-use change (deforestation). The effects of the carbon–climate feedback on temperature and carbon stocks are also shown.

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Kirchman, David L. "Microbial Solutions". En Microbes, 151–76. Oxford University PressNew York, 2024. http://dx.doi.org/10.1093/oso/9780197688564.003.0009.

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Abstract Microbes can help to reduce fossil fuel use, minimize the release of methane and nitrous oxide, and take carbon dioxide out of the atmosphere. Biomethane made by archaea is an important fuel source in many developing countries, while ethanol made by yeast makes up 10 percent or more of fuel used in cars in the United States and elsewhere. Inhibiting methanogenesis could reduce methane emissions from cattle and rice cultivation. Environmental microbiome engineering may lower nitrogen fertilizer use and release of nitrous oxide. Several strategies for taking carbon dioxide out of the atmosphere, known as negative emissions, rely on bacteria and fungi to form soil organic matter. One geoengineering scheme is to fertilize the Southern Ocean with iron to strengthen the biological pump and draw down atmospheric carbon dioxide. These possible solutions illustrate why understanding and solving today’s most important environmental problem, climate change, depends on microbes.

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Gehlen, Marion y Nicolas Gruber. "Biogeochemical Consequences of Ocean Acidification and Feedbacks to the Earth System". En Ocean Acidification. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199591091.003.0017.

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By the year 2008, the ocean had taken up approximately 140 Gt carbon corresponding to about a third of the total anthropogenic CO2 emitted to the atmosphere since the onset of industrialization (Khatiwala et al. 2009 ). As the weak acid CO2 invades the ocean, it triggers changes in ocean carbonate chemistry and ocean pH (see Chapter 1). The pH of modern ocean surface waters is already 0.1 units lower than in pre-industrial times and a decrease by 0.4 units is projected by the year 2100 in response to a business-as- usual emission pathway (Caldeira and Wickett 2003). These changes in ocean carbonate chemistry are likely to affect major ocean biogeochemical cycles, either through direct pH effects or indirect impacts on the structure and functioning of marine ecosystems. This chapter addresses the potential biogeochemical consequences of ocean acidification and associated feedbacks to the earth system, with focus on the alteration of element fluxes at the scale of the global ocean. The view taken here is on how the different effects interact and ultimately alter the atmospheric concentration of radiatively active substances, i.e. primarily greenhouse gases such as CO2 and nitrous oxide (N2O). Changes in carbonate chemistry have the potential for interacting with ocean biogeochemical cycles and creating feedbacks to climate in a myriad of ways (Box 12.1). In order to provide some structure to the discussion, direct and indirect feedbacks of ocean acidification on the earth system are distinguished. Direct feedbacks are those which directly affect radiative forcing in the atmosphere by altering the air–sea flux of radiatively active substances. Indirect feedbacks are those that first alter a biogeochemical process in the ocean, and through this change then affect the air–sea flux and ultimately the radiative forcing in the atmosphere. For example, when ocean acidification alters the production and export of organic matter by the biological pump, then this is an indirect feedback. This is because a change in the biological pump alters radiative forcing in the atmosphere indirectly by first changing the nearsurface concentrations of dissolved inorganic carbon and total alkalinity.

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Holbourn, Ann, Wolfgang Kuhnt, Karlos G. D. Kochhann, Kenji M. Matsuzaki y Nils Andersen. "Middle Miocene climate–carbon cycle dynamics: Keys for understanding future trends on a warmer Earth?" En Understanding the Monterey Formation and Similar Biosiliceous Units across Space and Time. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.2556(05).

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ABSTRACT The late early to middle Miocene period (18–12.7 Ma) was marked by profound environmental change, as Earth entered into the warmest climate phase of the Neogene (Miocene climate optimum) and then transitioned to a much colder mode with development of permanent ice sheets on Antarctica. Integration of high-resolution benthic foraminiferal isotope records in well-preserved sedimentary successions from the Pacific, Southern, and Indian Oceans provides a long-term perspective with which to assess relationships among climate change, ocean circulation, and carbon cycle dynamics during these successive climate reversals. Fundamentally different modes of ocean circulation and carbon cycling prevailed on an almost ice-free Earth during the Miocene climate optimum (ca. 16.9–14.7 Ma). Comparison of δ13C profiles revealed a marked decrease in ocean stratification and in the strength of the meridional overturning circulation during the Miocene climate optimum. We speculate that labile polar ice sheets, weaker Southern Hemisphere westerlies, higher sea level, and more acidic, oxygen-depleted oceans promoted shelf-basin partitioning of carbonate deposition and a weaker meridional overturning circulation, reducing the sequestration efficiency of the biological pump. X-ray fluorescence scanning data additionally revealed that 100 k.y. eccentricity-paced transient hyperthermal events coincided with intense episodes of deep-water acidification and deoxygenation. The in-phase coherence of δ18O and δ13C at the eccentricity band further suggests that orbitally paced processes such as remineralization of organic carbon from the deep-ocean dissolved organic carbon pool and/or weathering-induced carbon and nutrient fluxes from tropical monsoonal regions to the ocean contributed to the high amplitude variability of the marine carbon cycle. Stepwise global cooling and ice-sheet expansion during the middle Miocene climate transition (ca. 14.7–13.8 Ma) were associated with dampening of astronomically driven climate cycles and progressive steepening of the δ13C gradient between intermediate and deep waters, indicating intensification and vertical expansion of ocean meridional overturning circulation following the end of the Miocene climate optimum. Together, these results underline the crucial role of the marine carbon cycle and low-latitude processes in driving climate dynamics on an almost ice-free Earth.

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Actas de conferencias sobre el tema "Carbon biological pump"

Wilson, Jamie. "Physical, Biological and Ecological Drivers of the Biological Carbon Pump in the Cenozoic". En Goldschmidt2022. France: European Association of Geochemistry, 2022. http://dx.doi.org/10.46427/gold2022.12189.

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Liu, Dong, Yudi Zhou, Yongying Yang, Peituo Xu, Zhongtao Cheng, Jing Luo, Yupeng Zhang et al. "High-spectral-resolution lidar for ocean biological carbon pump studies". En OCEANS 2016 - Shanghai. IEEE, 2016. http://dx.doi.org/10.1109/oceansap.2016.7485738.

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Adloff, Markus, Ashley Dinauer, Charlotte Laufkötter, Frerk Pöppelmeier, Aurich Jeltsch-Thömmes y Fortunat Joos. "Carbon cycle implications of a dynamic, climate-sensitive biological pump". En Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.19528.

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Gaskell, Daniel, Mojtaba Fakhraee, Noah Planavsky y Pincelli Hull. "Ecological Adaptation Moderates the Temperature-Sensitivity of the Biological Carbon Pump". En Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.801.

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Cooper, E., S. Thomas, S. Ussher, D. Rush, M. Cunliffe y S. Lengger. "Marine fungi and the biological carbon pump - a quest for novel biomarkers for key players in the carbon cycle". En 30th International Meeting on Organic Geochemistry (IMOG 2021). European Association of Geoscientists & Engineers, 2021. http://dx.doi.org/10.3997/2214-4609.202134090.

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Zhang, Feifei, Maya Elrick, Alexandre Pohl, Keyi Cheng, Peter Crockford, Mojtaba Fakhraee, YiBo Lin et al. "Enhanced marine biological carbon pump as a trigger for Early Mississippian marine anoxia and climatic cooling". En Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.17195.

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Tabeta, Shigeru y Haruki Yoshimoto. "Investigation of Carbon Budget Around Artificial Upwelling Generator by a Coupled Physical-Biological Model". En ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2007. http://dx.doi.org/10.1115/omae2007-29653.

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There are several projects of generating upwelling by artificial structures to enhance the primary production expecting fish catch increase. From the view point of global environment, CO2 budget between atmosphere and ocean due to such technologies are also interesting. In this study, a coupled physical-biological model was developed to simulate the nitrogen and carbon cycles around artificial upwelling generator. The model is focusing on the degradation of particulate organic matter, because the process should much affects on the efficiency of the biological pump. The model is tuned by using the experimental data and applied to simulate the material cycle in the target area which is located north of Ikitsuki Island located northwest of Kyusyu, Japan, where an artificial seabed mound is installed to generate upwelling. The long-term carbon budget is also estimated by vertical one-dimensional ecosystem model using the parameters determined from the results of the three-dimensional coupled physical-biological model.

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A˚mand, Lars-Erik, Bo Leckner, Solvie Herstad Sva¨rd, Marianne Gyllenhammar, David Eskilsson y Claes Tullin. "Co-Combustion of Pulp- and Paper Sludge With Wood: Emissions of Nitrogen, Sulphur and Chlorine Compounds". En 17th International Conference on Fluidized Bed Combustion. ASMEDC, 2003. http://dx.doi.org/10.1115/fbc2003-097.

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Sludge from wastewater treatment plants in five Swedish pulp and paper mills has been burned together with wood in a circulating fluidised bed (CFB) boiler. The sludge was either mechanically dewatered or pre-dried. The mechanically dewatered sludge had to be fed with a pump, but the pre-dried sludge could be fed by the fuel feed system normally used for coal, wood chips or wood pellets. In parallel to the combustion tests in the CFB boiler the sludges were also investigated as single fuels in a small laboratory FB. The Swedish pulp and paper industry produces three major fractions of sludge: pure fibre sludge, sludge produced by employing a precipitation species like ironaluminiumsulphate, and finally, sludge subjected to biological cleaning. The way of production of the sludge influences its content of, for example, nitrogen, sulphur and chlorine, but the composition of the sludge is also influenced by the pulp and paper process. The present measurements show that the concentrations of nitrogen, sulphur and chlorine in the sludge have a great impact on the corresponding gaseous emissions from combustion. Actions to prevent these emissions could be necessary, depending on the origin of the sludge and treatment process used. In the present project all sludges were burned with wood-pellets as the main fuel under identical operating conditions, typical for a CFB boiler. Wood pellets were chosen as a well defined, low-polluting fuel that makes comparison of emissions from the sludges clear. Co-combustion with wood-pellets has the advantage of enabling operation also with wet sludges that cannot be used as single fuels without pre-drying. No actions were taken to improve sulphur and chlorine retention, by for example adding limestone. From a combustion point of view the co-combustion works well with low levels of carbon monoxide present in the flue gas and no light hydrocarbons.

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Trikis, Spyridon, Vaibhav Sumant, Muhammad Arshad, Anna Olliver, Meshaal Jarallah Abushereeda y John Brown. "Implementation of Odour Control Systems for Nuisance-free and Public Friendly Environment in Qatar". En The 2nd International Conference on Civil Infrastructure and Construction. Qatar University Press, 2023. http://dx.doi.org/10.29117/cic.2023.0164.

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The Public Works Authority (Ashghal) is contributing to the development of Qatar with the construction of first class, sustainable infrastructure with a high degree of public acceptance by utilizing best international practices. Pumping stations and sewage treatment works are traditionally constructed at the outskirts of cities, as they are generally associated with odour nuisance; however, as the cities are expanded, the facilities become part of the urban fabric and their operation becomes an issue of concern for nearby residents. To address this public concern, Ashghal has for its sewer infrastructure adopted odour emission limits as stringent as 0.5ppbV of hydrogen sulphide (H2S) and 0.5ouE/m3 of odour concentration, which are lower than recognisable levels by humans. Moreover, on the way to FIFA World Cup Qatar 2022™, Ashghal decided to install environmentally friendly and sustainable biological treatment units followed by activated carbon filters to ensure a nuisance-free environment at the existing Doha South Sewage Treatment Works (DS-STW) and the new Doha South Terminal Pump Station (DS-TPS). This paper presents methodologies for determining odour levels in existing and new units, available odour treatment technologies, and the selected treatment schemes for the above projects.

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Squibb, Carson, LoriAnne Groo, Adrian Bialy y Michael Philen. "Biologically Inspired Fluidic Flexible Matrix Composite Pumps for Wave Energy Conversion". En ASME 2016 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/smasis2016-9321.

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Inspired by the fibrillar network in plant cell walls and the helical fibers found in soft bodied hydrostats (e.g. worms, squid, elephant trunks, and octopus arms), fluidic flexible matrix composites (F2MCs) are composite tubes that consist of multiple layers of oriented, high performance fibers, such as carbon, precisely placed in a flexible matrix resin to form high-mechanical advantage actuators and variable stiffness materials. Unique to the F2MC tube is its ability to generate high pressures and volume change with a small external load as a result of the stiff reinforcement fiber orientation in the wall of the tube and the soft supporting elastomer. When a load is applied to the tubes, the volume of the composite pump is reduced and fluid is forced out of the tube by the reinforcing fibers. The objective of this research is to design, fabricate and characterize F2MCs for use in wave energy conversion where ocean waves provide the axial load to drive fluid through the pumps. F2MCs pumps are tested in a water basin and mechanically cycled between 0 Hz and 2 Hz at up to 17 percent strain. Instantaneous input power is found by measuring the displacement and applied force to the actuators, while output power values are derived from pressure and flow rate measurements at the tube outlet. From these measurements the actuator efficiency is subsequently determined.

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Informes sobre el tema "Carbon biological pump"

Buesseler, Ken O., Di Jin, Melina Kourantidou, David S. Levin, Kilaparti Ramakrishna y Philip Renaud. The ocean twilight zone’s role in climate change. Woods Hole Oceanographic Institution, febrero de 2022. http://dx.doi.org/10.1575/1912/28074.

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The ocean twilight zone (more formally known as the mesopelagic zone) plays a fundamental role in global climate. It is the mid-ocean region roughly 100 to 1000 meters below the surface, encompassing a half-mile deep belt of water that spans more than two-thirds of our planet. The top of the ocean twilight zone only receives 1% of incident sunlight and the bottom level is void of sunlight. Life in the ocean twilight zone helps to transport billions of metric tons (gigatonnes) of carbon annually from the upper ocean into the deep sea, due in part to processes known as the biological carbon pump. Once carbon moves below roughly 1000 meters depth in the ocean, it can remain out of the atmosphere for centuries to millennia. Without the benefits of the biological carbon pump, the atmospheric CO 2 concentration would increase by approximately 200 ppm 1 which would significantly amplify the negative effects of climate change that the world is currently trying to curtail and reverse. Unfortunately, existing scientific knowledge about this vast zone of the ocean, such as how chemical elements flow through its living systems and the physical environment, is extremely limited, jeopardizing the efforts to improve climate predictions and to inform fisheries management and ocean policy development.

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Tsikos, Hariloas, Sipesihle Rafuza, Zolane R. Mhlanga, Paul B. H. Oonk, Vlassis Papadopoulos, Adrian C. Boyce, Paul R. D. Mason, Christopher Harris, Darren R. Gröcke y Timothy W. Lyons. Carbon isotope evidence for water-column carbon and iron cycling in the Paleoproterozoic ocean and implications for the early biological pump: supplementary data file. Rhodes University, Department of Geology, 2020. http://dx.doi.org/10.21504/10962/138395.

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Artificial upwelling: More power for the ocean’s biological carbon pump. CDRmare, 2023. http://dx.doi.org/10.3289/cdrmare.31.

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Knowledge summary, Artificial upwelling: More power for the ocean’s biological carbon pump. CDRmare, 2023. http://dx.doi.org/10.3289/cdrmare.30.

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Algae, zooplankton and fish are among the key players in the biological carbon pump that allows the ocean to naturally remove carbon dioxide from the atmosphere and store it at great depths. However, for this mechanism to function optimally, it needs nutrients, which are lacking in many places, at least in the light-flooded surface water. By pumping up nutrient-rich deep water, humans could remedy this nutrient deficiency. But whether artificial upwelling would actually have an effect on the climate, what risks it would entail and whether it could be technically and legally implemented on a large scale, is still uncertain. The research mission CDRmare provides

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