Academic literature on the topic 'Sinking and sedimented particles'
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Journal articles on the topic "Sinking and sedimented particles"
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Honda, M. C., H. Kawakami, S. Watanabe, and T. Saino. "Fukushima-derived radiocesium in western North Pacific sediment traps." Biogeosciences Discussions 10, no. 2 (February 11, 2013): 2455–77. http://dx.doi.org/10.5194/bgd-10-2455-2013.
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Abstract. At two stations in the western North Pacific, K2 in the subarctic gyre and S1 in the subtropical gyre, time-series sediment traps were collecting sinking particles when the Fukushima Daiichi Nuclear Power Plant (FNPP1) accident occurred on 11 March 2011. Radiocesium (134Cs and 137Cs) derived from FNPP1 accident was detected in sinking particles collected at 500 m by late March 2011 and at 4810 m by early April 2011 at both stations. The sinking velocity of 134Cs and 137Cs was estimated to be 8 to 36 m day−1 between the surface and 500 m and > 180 m day−1 between 500 m and 4810 m. 137Cs specific activity varied from 0.14 to 0.25 Bq g−1 dry weight. These values are higher than those of surface seawater, suspended particles, and zooplankton collected in April 2011. Although the radiocesium may have been adsorbed onto or incorporated into clay minerals, correlations between 134Cs and lithogenic material were not always significant; therefore, the form of the cesium associated with the sinking particles is still an open question. The total 137Cs flux by late June at K2 and by late July at S1 was 0.5 to 1.7 Bq m−2 at both depths. Compared with 137Cs input to both stations by April 2011, estimated from the surface 137Cs activity and mixed layer depth and by assuming that the observed 137Cs flux was constant throughout the year, the estimated removal rate of 137Cs from the upper layer (residence time in the upper layer) was 0.3 to 1.5% (68 to 312 yr). The estimated removal rates and residence times are comparable to previously reported values.
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Coppola, Alysha I., Lori A. Ziolkowski, Caroline A. Masiello, and Ellen R. M. Druffel. "Aged black carbon in marine sediments and sinking particles." Geophysical Research Letters 41, no. 7 (April 1, 2014): 2427–33. http://dx.doi.org/10.1002/2013gl059068.
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Rontani, J. F., B. Charriere, A. Forest, S. Heussner, F. Vaultier, M. Petit, N. Delsaut, L. Fortier, and R. Sempéré. "Intense photooxidative degradation of planktonic and bacterial lipids in sinking particles collected with sediment traps across the Canadian Beaufort Shelf (Arctic Ocean)." Biogeosciences Discussions 9, no. 6 (June 26, 2012): 7743–81. http://dx.doi.org/10.5194/bgd-9-7743-2012.
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Abstract. The lipid content of seven samples of sinking particles collected with sediment traps moored at ~100 m depth in summer and fall across the Canadian Beaufort Shelf (Arctic Ocean) was investigated. Our main goal was to quantify and characterize the biotic and abiotic degradation processes that acted on sinking material during these periods. Diatoms, which dominated the phytoplanktonic assemblage in every trap sample, appeared to be remarkably sensitive to Type II (i.e. involving singlet oxygen) photodegradation processes in summer, but seemed to be relatively unaffected by biotic degradation at the same time. Hence, the relative recalcitrance of phytodetritus towards biodegradation processes during the Arctic midnight sun period was attributed to the strong photodegradation state of heterotrophic bacteria, which likely resulted from the efficient transfer of singlet oxygen from photodegraded phytoplanktonic cells to attached bacteria. In addition, the detection in trap samples of photoproducts specific to wax ester components found in herbivorous copepods demonstrated that zooplanktonic faecal material exported out of the euphotic zone in summer were as well affected by Type II photodegradation processes. By contrast, sinking particles collected during the autumn were not influenced by any light-driven stress. Further chemical analyses showed that photodegraded sinking particles contained an important amount of intact hydroperoxides, which could then induce a strong oxidative stress in underlying sediments.
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Rontani, J. F., B. Charriere, A. Forest, S. Heussner, F. Vaultier, M. Petit, N. Delsaut, L. Fortier, and R. Sempéré. "Intense photooxidative degradation of planktonic and bacterial lipids in sinking particles collected with sediment traps across the Canadian Beaufort Shelf (Arctic Ocean)." Biogeosciences 9, no. 11 (November 23, 2012): 4787–802. http://dx.doi.org/10.5194/bg-9-4787-2012.
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Abstract. The lipid content of seven samples of sinking particles collected with sediment traps moored at ~ 100 m depth in summer and fall across the Canadian Beaufort Shelf (Arctic Ocean) was investigated. Our main goal was to quantify and characterize the biotic and abiotic degradation processes that acted on sinking material during these periods. Diatoms, which dominated the phytoplanktonic assemblage in every trap sample, appeared to be remarkably sensitive to Type II (i.e. involving singlet oxygen) photodegradation processes in summer, but seemed to be relatively unaffected by biotic degradation at the same time. Hence, the relative recalcitrance of phytodetritus towards biodegradation processes during the Arctic midnight sun period was attributed to the strong photodegradation state of heterotrophic bacteria, which likely resulted from the efficient transfer of singlet oxygen from photodegraded phytoplanktonic cells to attached bacteria. In addition, the detection in trap samples of photoproducts specific to wax ester components found in herbivorous copepods demonstrated that zooplanktonic faecal material exported out of the euphotic zone in summer were affected by Type II photodegradation processes as well. By contrast, sinking particles collected during the autumn were not influenced by any light-driven stress. Further chemical analyses showed that photodegraded sinking particles contained an important amount of intact hydroperoxides, which could then induce a strong oxidative stress in underlying sediments.
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Boxhammer, T., L. T. Bach, J. Czerny, and U. Riebesell. "Technical Note: Sampling and processing of mesocosm sediment trap material for quantitative biogeochemical analysis." Biogeosciences Discussions 12, no. 22 (November 23, 2015): 18693–722. http://dx.doi.org/10.5194/bgd-12-18693-2015.
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Abstract. Sediment traps are the most common tool to investigate vertical particle flux in the marine realm. However, the spatial decoupling between particle formation and collection often handicaps reconciliation of these two processes even within the euphotic zone. Pelagic mesocosms have the advantage of being closed systems and are therefore ideally suited to study how processes in natural plankton communities influence particle formation and settling in the ocean's surface. We therefore developed a protocol for efficient sample recovery and processing of quantitatively collected pelagic mesocosm sediment trap samples. Sedimented material was recovered by pumping it under gentle vacuum through a silicon tube to the sea surface. The particulate matter of these samples was subsequently concentrated by passive settling, centrifugation or flocculation with ferric chloride and we discuss the advantages of each approach. After concentration, samples were freeze-dried and ground with an easy to adapt procedure using standard lab equipment. Grain size of the finely ground samples ranges from fine to coarse silt (2–63 μm), which guarantees homogeneity for representative subsampling, a widespread problem in sediment trap research. Subsamples of the ground material were perfectly suitable for a variety of biogeochemical measurements and even at very low particle fluxes we were able to get a detailed insight on various parameters characterizing the sinking particles. The methods and recommendations described here are a key improvement for sediment trap applications in mesocosms, as they facilitate processing of large amounts of samples and allow for high-quality biogeochemical flux data.
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Boxhammer, Tim, Lennart T. Bach, Jan Czerny, and Ulf Riebesell. "Technical note: Sampling and processing of mesocosm sediment trap material for quantitative biogeochemical analysis." Biogeosciences 13, no. 9 (May 13, 2016): 2849–58. http://dx.doi.org/10.5194/bg-13-2849-2016.
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Abstract. Sediment traps are the most common tool to investigate vertical particle flux in the marine realm. However, the spatial and temporal decoupling between particle formation in the surface ocean and particle collection in sediment traps at depth often handicaps reconciliation of production and sedimentation even within the euphotic zone. Pelagic mesocosms are restricted to the surface ocean, but have the advantage of being closed systems and are therefore ideally suited to studying how processes in natural plankton communities influence particle formation and settling in the ocean's surface. We therefore developed a protocol for efficient sample recovery and processing of quantitatively collected pelagic mesocosm sediment trap samples for biogeochemical analysis. Sedimented material was recovered by pumping it under gentle vacuum through a silicon tube to the sea surface. The particulate matter of these samples was subsequently separated from bulk seawater by passive settling, centrifugation or flocculation with ferric chloride, and we discuss the advantages and efficiencies of each approach. After concentration, samples were freeze-dried and ground with an easy to adapt procedure using standard lab equipment. Grain size of the finely ground samples ranged from fine to coarse silt (2–63 µm), which guarantees homogeneity for representative subsampling, a widespread problem in sediment trap research. Subsamples of the ground material were perfectly suitable for a variety of biogeochemical measurements, and even at very low particle fluxes we were able to get a detailed insight into various parameters characterizing the sinking particles. The methods and recommendations described here are a key improvement for sediment trap applications in mesocosms, as they facilitate the processing of large amounts of samples and allow for high-quality biogeochemical flux data.
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Berezina, Anfisa, Evgeniy Yakushev, Oleg Savchuk, Christian Vogelsang, and André Staalstrom. "Modelling the Influence from Biota and Organic Matter on the Transport Dynamics of Microplastics in the Water Column and Bottom Sediments in the Oslo Fjord." Water 13, no. 19 (September 28, 2021): 2690. http://dx.doi.org/10.3390/w13192690.
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The fate of microplastics (MP) in seawater is heavily influenced by the biota: the density of MP particles can be changed due to biofouling, which affects sinking, or MP can be digested by zooplankton and transferred into fecal pellets with increased sinking rate. We hypothesize that seasonal production and degradation of organic matter, and corresponding changes in the plankton ecosystem affect the MP capacity for transportation and burying in sediments in different seasons. This is simulated with a coupled hydrodynamical-biogeochemical model that provides a baseline scenario of the seasonal changes in the planktonic ecosystem and changes in the availability of particulate and dissolved organic matter. In this work, we use a biogeochemical model OxyDep that simulates seasonal changes of phytoplankton (PHY), zooplankton (HET), dissolved organic matter (DOM) and detritus (POM). A specifically designed MP module considers MP particles as free particles (MPfree), particles with biofouling (MPbiof), particles consumed by zooplankton (MPhet) and particles in detritus, including fecal pellets (MPdet). A 2D coupled benthic-pelagic vertical transport model 2DBP was applied to study the effect of seasonality on lateral transport of MP and its burying in the sediments. OxyDep and MP modules were coupled with 2DBP using Framework for Aquatic Biogeochemical Modelling (FABM). A depletion of MP from the surface water and acceleration of MP burying in summer period compared to the winter was simulated numerically. The calculations confirm the observations that the “biological pump” can be one of the important drivers controlling the quantity and the distribution of MP in the water column.
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Gaye-Haake, B., N. Lahajnar, K. Ch Emeis, D. Unger, T. Rixen, A. Suthhof, V. Ramaswamy, et al. "Stable nitrogen isotopic ratios of sinking particles and sediments from the northern Indian Ocean." Marine Chemistry 96, no. 3-4 (September 2005): 243–55. http://dx.doi.org/10.1016/j.marchem.2005.02.001.
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Mirnaghi, Fatemeh, Yujuan Hua, Bruce P. Hollebone, and Carl E. Brown. "Evaluation of Oil-Sediment Interactions and the Possibility of Oil Sinking in Marine Environments." International Oil Spill Conference Proceedings 2017, no. 1 (May 1, 2017): 2017–217. http://dx.doi.org/10.7901/2169-3358-2017.1.2017-217.
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ABSTRACT 2017-217 One of the major unknowns with respect to the fate and behavior of spilled dilbit is its state of buoyancy, particularly when mixed with sediments. What form do diluted bitumen and sediment mixtures take, and will they float or sink in water column? In this study, we evaluated the fate and behavior of Cold Lake Blend-Winter at three different weathering states (i.e., fresh, medium, and heavily weathered) in high-energy mixing marine conditions, with (and without) sufficient concentrations of sediments to ensure formation of oil-particulate aggregates (OPA). Conventional light crude oil and intermediate and heavy fuel oils were also included to serve as references for behavior of other types of oils. Two mineral sediments including kaolin (fine) and sand (coarse) as well as natural sediment from the Douglas Channel (DC) in northern British Columbia, (medium) were used for this evaluation. The resulting OPAs were characterized in terms of buoyancy, OPA density, particle size distribution, and morphology to better understand the oil-sediment interaction. In the absence of sediment, mixing of the oils with water resulted in meso/entrained–water-in-oil mixtures; these mixtures remained floating on the water surface. However, in presence of kaolin or the DC sediments, a significant portion of the OPA sank to the bottom of the water column for all oils, with the exception of the light crude oil and the highly weathered Cold Lake Blend-Winter. The later did not uptake as much sediment and instead formed discrete free-floating tarballs. In experiments with the larger sand sediment, no OPAs formed. The density and particle size analysis revealed that the OPAs of the oils with higher viscosity tended to have larger densities and particle sizes. Microscopic examination of the OPAs showed that all consisted of oil droplets surrounded by sediment particles and were present in single droplet or multiple-droplet clusters.
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Ostrovsky, I., and Y. Z. Yacobi. "Organic matter and pigments in surface sediments: possible mechanisms of their horizontal distributions in a stratified lake." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 6 (June 1, 1999): 1001–10. http://dx.doi.org/10.1139/f99-032.
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The analysis of spatial changes of organic matter and pigments (chlorophyll a, chlorophyll b, bacteriochlorophyll e, and phaeophytin a) in the uppermost bottom sediments was used to distinguish between sources of settled material in Lake Kinneret (Israel) during thermal stratification. The proportion of phytobenthic chlorophyll a decreased relatively to total chlorophyll a down to zero at 17 m. Bacteriochlorophyll e, derived from Chlorobium phaeobacteroides, was the most abundant pigment below the thermocline. Organic matter content in the sand-free sediment fraction and chlorophyll a to organic matter ratio were the lowest in the bottom area most extensively affected by shoaling internal seiches and where resuspension occurred. The proportion of resuspended matter sharply decreased with bottom depth in the hypolimnion. The importance of degraded materials of planktonic origin apparently increased towards the lake center. These distribution patterns could be achieved by dispersion of the rapidly sinking resuspended particles with fast metalimnetic jets and by focusing of the lighter planktonic particles by water motions in the turbulent benthic boundary layer. Our study showed that analysis of distribution of freshly settled organic components on the bottom may be a useful tool for understanding particle transport mechanisms in lakes.
Dissertations / Theses on the topic "Sinking and sedimented particles"
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McDonnell, Andrew M. P. "Marine particle dynamics : sinking velocities, size distributions, fluxes, and microbial degradation rates." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65326.
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Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2011.Cataloged from PDF version of thesis.
Includes bibliographical references.
The sinking flux of particulate matter into the ocean interior is an oceanographic phenomenon that fuels much of the metabolic demand of the subsurface ocean and affects the distribution of carbon and other elements throughout the biosphere. In this thesis, I use a new suite of observations to study the dynamics of marine particulate matter at the contrasting sites of the subtropical Sargasso Sea near Bermuda and the waters above the continental shelf of the Western Antarctic Peninsula (WAP). An underwater digital camera system was employed to capture images of particles in the water column. The subsequent analysis of these images allowed for the determination of the particle concentration size distribution at high spatial, depth, and temporal resolutions. Drifting sediment traps were also deployed to assess both the bulk particle flux and determine the size distribution of the particle flux via image analysis of particles collected in polyacrylamide gel traps. The size distribution of the particle concentration and flux were then compared to calculate the average sinking velocity as a function of particle size. I found that the average sinking velocities of particles ranged from about 10-200 m d- and exhibited large variability with respect to location, depth, and date. Particles in the Sargasso Sea, which consisted primarily of small heterogeneous marine snow aggregates, sank more slowly than the rapidly sinking krill fecal pellets and diatom aggregates of the WAP. Moreover, the average sinking velocity did not follow a pattern of increasing velocities for the larger particles, a result contrary to what would be predicted from a simple formulation of Stokes' Law. At each location, I derived a best-fit fractal correlation between the flux size distribution and the total carbon flux. The use of this relationship and the computed average sinking velocities enabled the estimation of particle flux from measurements of the particle concentration size distribution. This approach offers greatly improved spatial and temporal resolution when compared to traditional sediment trap methods for measuring the downward flux of particulate matter. Finally, I deployed specialized in situ incubation chambers to assess the respiration rates of microbes attached to sinking particles. I found that at Bermuda, the carbon specific remineralization rate of sinking particulate matter ranged from 0.2 to 1.1 d', while along the WAP, these rates were very slow and below the detection limit of the instruments. The high microbial respiration rates and slow sinking velocities in the Sargasso Sea resulted in the strong attenuation of the flux with respect to depth, whereas the rapid sinking velocities and slow microbial degradation rates of the WAP resulted in nearly constant fluxes with respect to depth.
by Andrew M. P. McDonnell.
Ph.D.
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Tilliette, Chloé. "Influence du fer et autres éléments traces issus des sources hydrothermales peu profondes sur la biogéochimie marine dans le Pacifique Sud-Ouest." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS046.
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L’océan Pacifique Sud-Ouest a été identifié comme un point chaud de fixation de diazote (N2) par les organismes diazotrophes, arborant des taux de fixation parmi les plus élevés des océans du globe. Le succès de ces espèces repose sur les concentrations non limitantes en fer dissous (DFe) dans la couche photique de la région, dont l’origine demeure méconnue. Dans le cadre de ce travail de thèse, la distribution du DFe a été étudiée le long d’un transect de 6100 km, allant de Nouméa jusqu’aux eaux de la gyre et traversant le Bassin de Lau et l’Arc des Tonga (175 °E à 166 °W, le long de 19–21 °S). Combinées avec une analyse optimale multiparamétrique des masses d’eau, les anomalies de DFe ont été déterminées sur la zone du transect, les plus notables étant présentes le long de l’Arc des Tonga. Les résultats ont démontré que les masses d’eau d’origine lointaine alimentant le Bassin de Lau ne peuvent expliquer les concentrations observées en surface dans cette région, permettant de conclure avec certitude que le DFe provient de sources hydrothermales peu profondes présentes le long de l’arc. Bien qu’une portion non négligeable de cet apport de DFe soit transportée sur de longues distances, une large majorité est rapidement éliminée à proximité des sources sous l’action de divers processus mis en lumière à l’aide d’un modèle en boîte. Outre le fer, les fluides hydrothermaux sont enrichis en de nombreux autres métaux susceptibles d’être toxiques pour les organismes. Ces fluides, directement introduits dans la couche photique, pourraient impacter le phytoplancton. Leur effet a été évalué lors d’une expérience innovante pendant laquelle des communautés planctoniques naturelles ont été soumises à un gradient d’enrichissement en fluides hydrothermaux. Malgré un effet toxique initial de quelques jours, les apports hydrothermaux ont finalement induit des taux de fixation de N2, de productivité et d’export de matière organique deux à trois fois plus élevés que dans le contrôle non enrichi. Cet effet fertilisant résulte probablement de la détoxification de l’environnement, riche en de nombreux éléments potentiellement toxiques, par des écotypes résistants capables de produire des ligands forts, les thiols, limitant la biodisponibilité de certains métaux. L’apport additionnel d’éléments fertilisants par les fluides, en particulier le DFe, a ainsi permis la croissance ultérieure des espèces les plus sensibles. Ces résultats expérimentaux, reproduisant fidèlement les observations in-situ, confirment l’implication des fluides hydrothermaux peu profonds dans la forte productivité observée dans la région. Les sources hydrothermales ont pu être tracées à différentes échelles spatiales et temporelles par le déploiement de pièges à sédiments dérivants (durant quelques jours, le long de l’Arc des Tonga) et fixe (durant une année, le long de la dorsale de Lau) et par le carottage des sédiments du fond marin aux sites de déploiement des pièges (échelle de temps géologique). Le traçage Al-Fe-Mn a révélé que le matériel lithogénique exporté à petite et large échelle spatiale dans la région provenait de sources hydrothermales peu profondes et/ou profondes localisées le long de l’Arc des Tonga. Cette empreinte hydrothermale a également été détectée dans les sédiments, notamment à proximité de la dorsale de Lau où la présence d’une importante source active est fortement suspectée. Finalement, les dynamiques similaires observées pour l’export de particules d’origine biologique et hydrothermale suggèrent que la production de surface serait liée aux apports hydrothermaux dans la couche photique. En conclusion, ce travail de thèse a démontré l’impact de sources hydrothermales peu profondes sur le cycle des éléments traces, notamment du fer, dans la colonne d’eau et les sédiments, ainsi que leur lien avec la productivité biologique dans la région du Pacifique Sud-OuestThe Western Tropical South Pacific Ocean has been identified as a hotspot for dinitrogen (N2) fixation by diazotrophic organisms, with some of the highest rates recorded in the global ocean. The success of these species relies on non-limiting concentrations of dissolved iron (DFe) in the photic layer of the region, whose origin remains unclear. In this thesis work, the distribution of DFe was studied along a 6100-km transect from Noumea to the gyre waters, crossing the Lau Basin and the Tonga Arc (175°E to 166°W, along 19-21°S). Combined with an optimal multiparametric water mass analysis, DFe anomalies were determined over the transect area, the most notable being present along the Tonga Arc. The results demonstrated that water masses of remote origin entering the Lau Basin could not explain the concentrations observed at the surface in this region, leading to the confident conclusion that DFe originates from shallow hydrothermal sources present along the arc. Although a non-negligeable portion of this DFe input is transported over long distances, a large majority is rapidly removed near the sources through a variety of processes highlighted by a box model. Besides iron, hydrothermal fluids are enriched in numerous other metals that may be toxic to organisms. These fluids, introduced directly into the photic layer, could have an impact on phytoplankton. Their effect was evaluated in an innovative experiment during which natural plankton communities were subjected to an enrichment gradient of hydrothermal fluids. Despite an initial toxic effect of a few days, hydrothermal inputs ultimately induced N2 fixation, productivity and organic matter export rates two to three times higher than those of the non-enriched control. This fertilizing effect probably results from the detoxification of the environment, rich in numerous potentially toxic elements, by resistant ecotypes able to produce strong ligands, such as thiols, limiting the bioavailability of certain metals. The additional supply of fertilizing elements by the fluids, in particular DFe, thus allowed the subsequent growth of the most sensitive species. These experimental results, faithfully reproducing the in-situ observations, confirm the involvement of shallow hydrothermal fluids in the high productivity observed in the region. Hydrothermal sources could be traced at different spatial and temporal scales through the deployment of drifting (for a few days, along the Tonga Arc) and fixed (for a year, along the Lau Ridge) sediment traps and through the coring of seafloor sediments at the trap deployment sites (geological time scale). Al-Fe-Mn tracing revealed that the lithogenic material exported at small and large spatial scales in the region originated from shallow and/or deep hydrothermal sources located along the Tonga Arc. This hydrothermal signature has also been detected in the seafloor sediments, particularly in the vicinity of the Lau Ridge where the presence of a major active source is strongly suspected. Finally, the similar patterns observed for the export of biological and hydrothermal particles suggest that surface production is closely linked to hydrothermal inputs into the photic layer. In conclusion, this thesis work has demonstrated the influence of shallow hydrothermal sources on the fate of trace elements, particularly iron, in the water column and seafloor sediments, and their link to biological productivity in the Western Tropical South Pacific region
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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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Downs, Janet Newton. "Implications of the phaeopigment, carbon and nitrogen content of sinking particles for the origin of export production /." Thesis, Connect to this title online; UW restricted, 1989. http://hdl.handle.net/1773/10984.
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Traill, CD. "Lithogenic particle flux to the subantarctic Southern Ocean : a multi-tracer estimate using sediment trap samples." Thesis, 2021. https://eprints.utas.edu.au/38433/1/Traill_whole_thesis.pdf.
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The delivery of lithogenic material from atmospheric dust to remote regions of the Southern Ocean is thought to be a key source of micronutrients, particularly iron, essential for phytoplankton. Here, we present a time series of lithogenic flux estimates from 2010 to 2019 using sinking particles collected by sediment traps at 1000m at the Southern Ocean Time Series mooring station in the subantarctic Southern Ocean. Lithogenic flux estimates were made based on aluminium, titanium, iron and thorium concentration in sinking particles and showed good agreement with one another. A multi-tracer flux estimate was calculated using an average of all individual tracer flux estimates in order to reduce biases associated with each element’s reactivity in seawater. This mean lithogenic flux exhibited a strong seasonality, with two peaks in late spring and in summer. The magnitude of our multi-tracer lithogenic flux was comparable to previous sediment trap-based fluxes reported in the Southern Ocean and to 230Th-normalised lithogenic fluxes from core-top sediments at the same study location. A lack of lithogenic tracer enrichment in our samples compared to the average upper continental crust values indicated that lithogenic material dominates iron supply in this region. Sinking particle samples from SOTS showed similar Fe enrichment to aerosols collected over southern marine regions around Australia, suggesting that Australian dust may be the primary lithogenic source to SOTS sinking particles. Evidence of lead (Pb) enrichment in sediment trap samples at 1000m highlighted a non-negligible contribution from anthropogenic particles in SOTS sediments, the later source which could represent a secondary Fe supply to the samples. Therefore, we concluded that aeolian emissions from Australia likely compose the primary source of lithogenic particles to SOTS subantarctic Southern Ocean 1000m-deep waters. This hypothesis was further supported by maximum lithogenic particle flux at 1000m depth in late spring preceded by seasonal atmospheric aerosol loading from aerosol optical depth and satellite reanalysis modelled dust deposition maxima that occurred during the Australian dust storm season in spring across the study period.
While carbon export at 1000m showed good correlation with surface chlorophyll concentrations at SOTS across the study period, a lack of linear relationship between lithogenic fluxes at 1000m and productivity leaves the link between marine productivity and 1000m-deep sinking particles in this subantarctic region of the Southern Ocean unclear.
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Hu, Po-Kai, and 胡博凱. "Comparison of POC/Th-234 in sinking particles and suspended particles." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/82622233158935392804.
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碩士國立臺灣海洋大學
海洋環境化學與生態研究所
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234Th/238U has been increasingly used as a tracer to estimate particulate organic carbon（POC）fluxes by calculating product of the POC/234Th ratio of sinking particles and the 234Th flux. Large（>50 m）pump-collected particles are assumed to be representative of sinking particles. Hung and Gong（2010）in the Northwestern Pacific found that small（<50 m）sinking particles（collected by sediment traps）dominated the bulk POC flux, but they did not simultaneously measure the contents of POC and Th-234 in both trap- and in situ pump-collected particles. Here we present POC and 234Th data from the N Pacific for two particle size classes（1-50 and 50-355 m）from both trap- and pump-collected particles in the northwestern Pacific using three methods：trap-collected particles with gravity filtration（PGF）, trap-collected particles with natural filtration（PNF）, and pump-collected particles with sequential filtration（PSF）. POC in small（<50 µm）particles using PGF, PNF and PSF accounted for 34-78%, 30-75% and 88-98%, respectively. Th-234 in small（<50 µm）particles using PGF, PNF and PSF showed a similar range, i.e., it accounted for 44-89%, 11-75% and 43-98%, respectively. These results clearly show that pump-collected large and small particles are not only different from trap-collected particles in terms of POC and Th-234 concentrations, but also POC and Th-234 contents in small（pump-collected）particles are significantly larger than large（pump-collected）particles.These results suggest that the contribution of particles smaller than 50 m to the settling flux is larger than previously thought. Thus, POC/234Th ratios conventionally derived from large pump-collected particles may not be appropriate for esti-mating POC flux. Instead, we suggest that POC/234Th ratios in sinking particles should be used for estimating POC flux.
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Chien, Ying-Hsueh, and 錢映學. "Size distribution of sinking particles in different marine environments." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/24357433465420358917.
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碩士國立中山大學
海洋地質及化學研究所
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234Th/238U has been used to estimate particulate organic carbon (POC) export fluxes, based on the POC/234Th ratio of sinking particles and the 234Th flux, in the ocean. However, the 234Th-derived POC flux may be significantly biased due to the variation of use POC/234Th ratios from large particles (>50μm). More recently, some studies use particle size distributions in the upper ocean to calculate POC flux. Although Hung and Gong (2010) and Hung et al. (2012) have measured the size distributions in sinking particle, but their experiments were limited in some regions. Therefore, the size distributions in sinking particle are not clearly. In this study, we collected sinking particles with three different instruments (Laser in-situ Scattering and Transmissometry (LISST-100X), cylindrical and conical sediment traps) from the northern South China Sea, the upwelling region off the northeast Taiwan (where diatoms are the most dominant group) and the Northwestern Pacific (where picoplanktondominated), measured POC and 234Th data for various particle size classes (1-50 μm, 50-330 μm and >330 μm, (herein we defined that < 50μm is the “ small particle”). The results show the small particles, investigated by-cylindrical and conical traps, contained the largest proportion of POC (46~66%, by cylindrical traps) and (37~75%, by conical traps) and the distribution of particle size measured by LISST-100X howed small particles had the elevated shares of total particle volume. SEM images of bulk (without sequential filtration) sinking particles also evidence that sinking particles contained many small particles. Besides, the model-derived POC flux in small particles using particle size distribution is quite comparable with the measured POC flux by sediment trap, while the POC fluxes measured by both methods show pronounced difference suggesting that it is worthy for studying in the future. Overall, our results suggest that the contribution of particles smaller than 50 μm to the sinking POC flux can be a major fraction of the total sinking flux, and thus, particles smaller than 50 μm cannot be ignored when using Th-234/U-238 disequilibrium to estimate POC flux in the water column.
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Hvitfeldt, Iversen Morten [Verfasser]. "Carbon turnover in sinking particles in the marine environment / vorgelegt von Morten Hvitfeldt Iversen." 2009. http://d-nb.info/995315612/34.
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Ebersbach, Friederike [Verfasser]. "Flux and modification of sinking particles : three field studies in the Southern Ocean / Friederike Ebersbach." 2010. http://d-nb.info/1011096714/34.
Full textBook chapters on the topic "Sinking and sedimented particles"
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Knauer, George. "The Analytical Determination of Mass Flux, Inorganic and Organic Carbon and Nitrogen Flux in Rapidly Sinking Particles Collected in Sediment Traps." In Marine Particles: Analysis and Characterization, 79–82. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm063p0079.
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Holmes, M. E., G. Lavik, G. Fischer, and G. Wefer. "Nitrogen Isotopes in Sinking Particles and Surface Sediments in the Central and Southern Atlantic." In The South Atlantic in the Late Quaternary, 143–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-642-18917-3_8.
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Holmes, M. E., C. Eichner, U. Struck, and G. Wefer. "Reconstruction of Surface Ocean Nitrate Utilization Using Stable Nitrogen Isotopes in Sinking Particles and Sediments." In Use of Proxies in Paleoceanography, 447–68. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-58646-0_18.
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Davis, Bruce, and Keyna O'Reilly. "Electron Probe Micro Analysis of Sedimented Zirconium Particles in Magnesium." In Magnesium, 242–47. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527603565.ch37.
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Bodungen, Bodo V., Marita Wunsch, and Heike Fürderer. "Sampling and Analysis of Suspended and Sinking Particles in the Northern North Atlantic." In Marine Particles: Analysis and Characterization, 47–56. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm063p0047.
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Hayakawa, Kazuhide, and Nobuhiko Handa. "Fatty Acid Composition of Sinking Particles in the Western North Pacific." In Dynamics and Characterization of Marine Organic Matter, 105–15. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-017-1319-1_5.
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Ishiwatari, R., K. Yamada, K. Matsumoto, H. Naraoka, S. Yamamoto, and N. Handa. "Source of Organic Matter in Sinking Particles in the Japan Trench: Molecular Composition and Carbon Isotopic Analyses." In Dynamics and Characterization of Marine Organic Matter, 141–68. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-017-1319-1_7.
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Nakatsuka, Takeshi, Ayako Hosokawa, Nobuhiko Handa, Eiji Matsumoto, and Toshiyuki Masuzawa. "14C Budget of Sinking Particulate Organic Matter in the Japan Trench: A New Approach to Estimate the Contribution from Resuspended Particles in Deep Water Column." In Dynamics and Characterization of Marine Organic Matter, 169–86. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-017-1319-1_8.
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Smith, George E., and Raghav Seth. "The Historical Background: Brownian Motion as of 1905." In Brownian Motion and Molecular Reality, 88–128. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190098025.003.0003.
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The mystery of Brownian motion had been announced with its discovery by Robert Brown in 1828: the persistence of the motion of solid particles in liquids for indefinite periods of time instead of sinking as sediment to the bottom. Once molecular-kinetic theory emerged more fully a few years later, it was the obvious candidate for explaining the phenomenon. Nevertheless, those developing kinetic theory in the second half of the century, Maxwell and Boltzmann, appear to have ignored it. The chapter summarizes research on Brownian motion during the nineteenth century, indicating why leading physicists ignored it, and what developments in the first five years of the twentieth century led to its suddenly becoming so important to kinetic theory. This background supplements that of Chapter 2, completing the historical context for the developments covered in subsequent chapters.
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Adams, R., and R. Thompson. "Are the Sinking Velocities of Microplastics Altered Following Interactions With Austrominius modestus and Sediment Particles?" In Fate and Impact of Microplastics in Marine Ecosystems, 99–100. Elsevier, 2017. http://dx.doi.org/10.1016/b978-0-12-812271-6.00097-1.
Full textConference papers on the topic "Sinking and sedimented particles"
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Raven, Morgan, Samuel Webb, and Richard Keil. "Sulfidic Conditions Transform Sinking Marine Particles." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.7887.
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Evans, Natalya, James Moffett, Daniele Bianchi, and Gregory Cutter. "Identifying the primary oxidation processes for particulate sulfide using mechanistic models of reducing microenvironments in large, sinking particles." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.4963.
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Choi, Hyuntae, Eun Jin Yang, Sung-Ho Kang, and Kyung-Hoon Shin. "Seasonal Nitrogen Baseline (δ15N) Variation of Sinking Particles in the Western Arctic Revealed by Compound-Specific Isotope Analysis of Amino Acids." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.428.
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Nabian, Mohammad Amin, and Leila Farhadi. "Numerical Simulation of Solitary Wave Using the Fully Lagrangian Method of Moving Particle Semi Implicit." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-22237.
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A mesh-less numerical approach, called the moving particle semi implicit method (MPS), is presented to solve inviscid Navier-Stokes equations in a fully Lagrangian form using a fractional step method. This method consists of splitting each time step in two steps. The fluid is represented with particles and the motion of each particle is calculated through interactions with neighboring particles by means of a kernel function. In this paper, the MPS method is used to simulate a dynamic system consisting of a heavy box sinking vertically into a water tank, known as Scott Russell’s wave generator problem. This problem is an example of a falling rock avalanche into natural or artificial reservoirs. The box sinks into water tank and as a result the water is heaved up to form a solitary wave and a reverse plunging wave which forms a vortex. This vortex follows the solitary wave down the water tank. The good agreement between the numerical simulation and the analytical solution confirms the accuracy of the model. This proves the applicability of the present model in simulating complex free surface problems. The number of particles on free surface is presented as an indicator of stability of the model.
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Xu, Yuanqi, Jiasong Fang, Jiangyan LI, and Jiahua Wang. "Hydrostatic pressure Exerts Different Effects on Community Structure and Metabolic Capacities of Marine Particle-Attached and Free-Living Microorganisms in Decomposition of the Sinking Particles." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.7377.
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North, Mark T., and Wei-Lin Cho. "High Heat Flux Liquid-Cooled Porous Metal Heat Sink." In ASME 2003 International Electronic Packaging Technical Conference and Exhibition. ASMEDC, 2003. http://dx.doi.org/10.1115/ipack2003-35320.
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An advanced heat sinking technology is described in which heat is dissipated by flowing the liquid coolant through a matrix of well-bonded metallic particles. This porous metal heat sink has the capability to dissipate heat flux of 500W/cm2 or more with a unit area thermal resistance of 0.1°C·cm2/W. The construction of one incarnation of this class of heat sink developed for cooling of a high-power stack of laser diode arrays is described. Tradeoffs between pressure drop and thermal resistance are identified with regard to particle size and other geometric parameters. The patented manifolding geometry allows the cooling area to be scaled up without significantly increasing the overall pressure drop. Experimental data showing thermal resistance and pressure drop at a variety of different water flow rates is also presented. Applications for this technology can include cooling of laser diode arrays and high power electronic components such as CPUs.
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Renger, Stefan. "Investigation of the Agglomeration and the Break-Up of Isolation Material." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75391.
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The description of the complex flow of coolant water with particles is necessary to evaluate safety relevant effects of the sedimentation of isolation material on sump-sieves in nuclear power station. Classifying and modeling of the different phenomena maybe important in the case of a coolant accident, because the isolation material can be transported into the reactor containment, the building sump of the containment and into the associated systems [1]. In order to ensure the heat dissipation from the reactor core and the containment the cooling systems transport the water from the sump into the condensation chamber and then into the reactor pressure vessel. The functionality of the pumps can be affected by a high allocation of the sieves with fractionated isolation material. In this case the heat dissipation from fuel elements is not guaranteed. The transport of the material will be simulated with the CFD-code. The modeling of the flow with particles is very complex, because of the structure of the particles and their interaction with the fluid. There are different classes of particles with different attributes, e.g. sinking velocity. So one needs more than one disperse phase to describe the whole process, which is associated with a lot of computing power and not realizable for large geometries. The paper deals with experimental and methodical activities for the description of the agglomeration and the break-up of isolation material in fluid flow. The aim of this work is to describe the evolution of the volume parts of the different particle classes turbulent flows depending on the time in. The modeling phase starts with a very simple model to describe 3 particle classes (x, y, z) and results in a differential equation system with 3 equations. To describe all classes the model has to be expanded. Therefore the Lindenmayer-System approach has been adopted. These systems can be taken in cases where self-similarity takes place. The result is a differential equation system with iterations for the three classes (x(i), y(i), z(i)), with i as the parameter for the number of subclasses. The values for the agglomeration and break-up rates will be taken from experiments. As a result a model has been created which describes the evaluation of the different particles classes in turbulent flow. It helps to choose the correct particle class in the CFD simulation depending on the situation to simulate.
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Talapatra, Siddharth, Jiarong Hong, Jian Sheng, Becky Waggett, Pat Tester, and Joseph Katz. "A Study of Grazing Behavior of Copepods Using Digital Holographic Cinematography." In ASME 2008 Fluids Engineering Division Summer Meeting collocated with the Heat Transfer, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/fedsm2008-55196.
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Generating proper feeding currents for entraining prey is one of the important features in the grazing behavior of (∼1mm) copepods. These feeding currents vary with the copepod species, as well as with the species or strains and concentration of prey (∼10 μm) dinoflagellates. Calanoid copepods also hover for a while, while slowly sinking, and then intermittently jump to a different location. In our study, we employed high speed digital holographic cinematography to measure elements of the flow field around copepods in an environment seeded with dinoflagellates. In most cases, the flow field and feeding currents were characterized based on the trajectories of the dinoflagellates. However, in some of the tests we also added neutrally buoyant 20 μm particles as independent flow tracers. At low magnifications, we simultaneously recorded two perpendicular views to obtain the same spatial resolution in all directions. Data were recorded at varying magnifications and frame rates. In recent experiments, we exposed the copepods to different strains of the same dinoflagellate species that have varying levels of toxicity, and measured the resulting changes to the grazing behavior of the copepods. Here we present results from two of these experimental setups: Acartia tonsa with Karlodinium veneficum (non toxic strain) and Acartia tonsa in particle seeded flow. Issues such as swimming characteristics, feeding classification (raptorial vs. filter feeding approaches) and copepod response to different environmental settings were addressed.
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Huang, Luofeng, Seogeng Riyadi, I. Ketut Aria Pria Utama, and Giles Thomas. "Computational Study on the Transmission of COVID-19 Virus Inside a Ship." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-80182.
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Abstract To investigate the operational improvements of vessels under the impact of COVID-19, this work has developed a Computational Fluid Dynamics model combined with Lagrangian particles to study the airborne transmission of COVID-19 viruses inside a ship. Initially a generic model was established to enable validation against experimental results for the diffusion of flu virus in an idealised room. Following this, the room geometry was replaced by the superstructure of a full-scale crew boat. Considering the boat advancing in open water, simulations were conducted to study the particulate flow due to a person coughing and speaking, with the boat’s forward door open and closed. The results have shown that, when the forward door is open, a significant airflow can carry the viruses to make extensive contacts with the passengers. This led to the suggestion of keeping the door closed. However, when the forward door is shut, face-to-face speaking can generate viruses that can float in the air for a long time, and it was found that the viruses mainly stay within a half-meter distance in front of the speaking person, before sinking to attach to the deck. Thus, a social-distancing suggestion on seat arrangement has been highlighted to minimise the risk of contagion. Overall, this work is expected to inform guidelines on hygienic and reconfiguring means for operators to counter COVID-19 and potentially the spread of similar viruses in the future.
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Bartolini, Lorenzo, Lorenzo Marchionni, Antonio Parrella, and Luigino Vitali. "Advanced FE Modelling Approach for Pipeline Hooking Interaction of Dragged Anchors." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77473.
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Offshore pipelines, located in areas with high/medium ship traffic, are exposed to threats such as dragged anchors, dropped objects, sinking ships, etc.. In the last years, there have been a few accidents where subsea pipelines or cables have been hooked and damaged by dragged anchors. These incidents have been caused both by emergency and accidentally dragged anchors. Two of the most serious incidents to pipelines caused by an accidentally dragged anchor involved the Trans Mediterranean gas pipelines in 2008 and the Kvitebjørn gas pipeline in the North Sea in 2007. The interaction mechanism between the pipeline and an anchor dragging on the seafloor is affected by different parameters (i.e. anchor size, chain length, water depth, soils geo-technics, anchor speed, incident angle between the pipeline and the anchor dragging direction). In common practice, the occurrence of hooking events is assessed by implementing specified interpretative model involving basically typical anchor dimensions for the different ship classes and expected soil pipe interaction scenarios. Major efforts have been made to develop a 3D Finite Element model with the aim of improving the simulation capabilities of engineers to address and anticipate the mechanism of pipeline and dragged anchor interaction. The model presented in this paper is based on the Coupled Eulerian Lagrangian (CEL) technique. With respect to typical simplified FE models, implementing the seabed as an analytic surface, this advanced technique (i.e. CEL) allows one to model the seabed as a deformable Eulerian domain, in which the anchor (and the pipeline) can penetrate. The seabed settlement and the displacement of soil particles due to anchor motion can be fully calculated. The FE Model includes the steel pipeline geometry and the external concrete coating, the surrounding water, the deformable seabed and the 3D anchor geometry with its chain. Scope of this assessment is to improve the understanding of the pipeline and anchor interaction event. In particular the focus is on the mechanisms and dynamics of accidental events which lead to the occurrence of anchor engagement with the pipeline. Eventually, the final goal is to refine and take into due account the contribution of accidentally dragged anchor scenario in the overall procedure for pipeline design against threats posed by commercial ship traffic. In this paper: • The state of the art about the classical analysis methodology recommended by standards to evaluate the interaction between the pipeline and the accidental dragged anchors is briefly described; • A FEM based analysis methodology is drawn and proposed to address the potential for pipeline hooking by the accidentally dragged anchor event; • A typical application is presented.
Reports on the topic "Sinking and sedimented particles"
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Siegel, David A., Ivona Cetinic, Andrew F. Thompson, Norman B. Nelson, Michaela Sten, Melissa Omand, Shawnee Traylor, et al. EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) North Atlantic sensor calibration and intercalibration documents. NASA STI Program and Woods Hole Oceanographic Institution, October 2023. http://dx.doi.org/10.1575/1912/66998.
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The following documents collect information regarding the calibration and intercalibration of various sensors that were deployed during the North Atlantic field component of the NASA EXPORTS project (EXPORTS NA), which took place between May 4 and June 1, 2021 (Johnson et al., 2023). The EXPORTS NA campaign was designed to to provide a contrasting end member to the earlier North Pacific field campaign, and focused on carbon export associated with the North Atlantic spring bloom in which gravitational sinking of organic particles, the physical advection and mixing, and active transport by vertically migrating zooplankton are all expected to provide significant flux pathways. During EXPORTS NA data sets were collected from a variety of shipbased, autonomously-piloted, and Lagrangian platforms. Intercalibration activities were tasked to different groups within the EXPORTS project team. Team leads and contact information are listed below. The overarching goal of these activities was to identify a trusted sensor, carry out a careful calibration of this sensor, then base any intercalibraiton needs off of this sensor, occasionally propagating information across platforms. Full details of the intercalibration approach, assumptions, and summary are provided in the attached documents. All calibration and intercalibration activities were completed before data set were uplaoded to the NASA SeaBASS data repository. Data related to this cruise can be publicly accessed at: https://seabass.gsfc.nasa.gov/cruise/EXPORTSNA Updates to calibration and intercalibration documents required to reflect revised data sets will also be provided through SeaBASS. Questions concerning referencing these documents or accessing data sets should be directed to Inia Soto Ramos. NASA EXPORTS Science Lead: David Siegel, davesiegel@ucsb.edu NASA EXPORTS Project Scientist: Ivona Cetini´c, ivona.cetinic@nasa.gov NASA EXPORTS Data Manager: Inia Soto Ramos, inia.m.sotoramos@nasa.gov Calibration and intercalibration leads Temperature and salinity sensors: Andy Thompson, andrewt@caltech.edu Chlorophyll fluorescence sensors: Melissa Omand & Kaley Sten, momand@uri.edu Oxygen sensors: Shawnee Traylor & Roo Nicholson, shawnee@mit.edu Optical backscatter sensors: Xiaodong Zhang, Xiaodong.Zhang@usm.edu Lagrangian float sensors: Eric D’Asaro, dasaro@apl.washington.edu Underway sensors: Leah Johnson, leahjohn@uw.edu Underwater Vision Profiler (UVP)-Particle Size Distribution (PSD): David Siegel, davesiegel@ucsb.edu