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Siqueira, Beatriz, Jonas Teixeira Nery e Oliver Messeguer-Ruiz. "Análise dos Índices das Temperaturas Superficiais das Zonas Intertropicais dos Oceanos Pacífico e Atlântico associados às precipitações no Nordeste do Brasil". Revista Brasileira de Geografia Física 14, n. 2 (20 maggio 2021): 1081. http://dx.doi.org/10.26848/rbgf.v14.2.p1081-1093.
Testo completoAbstract (sommario):
O objetivo deste estudo foi analisar, através de índices climáticos, a variabilidade da precipitação na região Nordeste do Brasil. Para tanto foram utilizados dados em ponto de grade para gerar o índice de precipitação, bem como dados da National Oceanic Atmospheric Administration (NOAA) para gerar os índices de temperatura do oceano Pacífico (setor EN3.4) e do oceano Atlântico tropical norte e sul. O período de análise foi de 1970 a 2012. Com base nesses índices foram realizadas correlações lineares de Pearson, entre o oceano Pacífico e o Atlântico tropical norte e o oceano tropical sul, na costa do Brasil. Anomalias de precipitação também foram calculadas para alguns anos de ocorrência do evento El Niño, denotando expressiva variabilidade de um evento para outro. De maneira geral, as correlações entre os índices envolvendo os referidos oceanos foram positivas e expressivas, o que permite considerar a influência dos oceanos na dinâmica das chuvas na área de estudo. A importância do Atlântico sul é mais nítida quando os índices de temperatura da superfície do mar apresentaram o mesmo sinal, tanto no Pacífico quanto no Atlântico, o que implica em correlações mais marcadas.Palavras-chave: Forçante climática, El Niño 3.4, Nordeste do Brasil, Atlântico tropical, Anomalias da precipitação.Analysis of Surface Temperature Indices of the Intertropical Zones of the Pacific and Atlantic Oceans associated with rainfall in Northeastern Brazil ABSTRACTThe objective of this study was to analyze, through climatic indices, the variability of precipitation in the Northeast region of Brazil. For that purpose, grid point data were used characterize the precipitation behaviour, as well as data from the National Oceanic Atmospheric Administration (NOAA) to determine the temperature of the Pacific Ocean (sector EN3.4) and the tropical North and South Atlantic Ocean. Based on these data, correlations were made, which are characterized as marked, between the dynamics of the Pacific Ocean and the dynamics of the tropical North and South Atlantic, directly influencing the precipitation regime in Northeast Brazil. Precipitation anomalies were also calculated for some years of the El Niño event, showing significant variability from one event to another. In general, the correlations between the indexes involving the referred oceans were positive and expressive, which allows considering the influence of the oceans on the dynamics of rainfall in the study area. The importance of the South Atlantic is clearer when the sea surface temperature indices show the same sign, both in the Pacific and in the Atlantic, which implies more marked correlations.Keywords: Climate forcing, El Niño 3.4, Northeast Brazil, Tropical Atlantic, Precipitation anomalies.
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Auclair-Desrotour, P., S. Mathis, J. Laskar e J. Leconte. "Oceanic tides from Earth-like to ocean planets". Astronomy & Astrophysics 615 (luglio 2018): A23. http://dx.doi.org/10.1051/0004-6361/201732249.
Testo completoAbstract (sommario):
Context. Oceanic tides are a major source of tidal dissipation. They drive the evolution of planetary systems and the rotational dynamics of planets. However, two-dimensional (2D) models commonly used for the Earth cannot be applied to extrasolar telluric planets hosting potentially deep oceans because they ignore the three-dimensional (3D) effects related to the ocean’s vertical structure. Aims. Our goal is to investigate, in a consistant way, the importance of the contribution of internal gravity waves in the oceanic tidal response and to propose a modelling that allows one to treat a wide range of cases from shallow to deep oceans. Methods. A 3D ab initio model is developed to study the dynamics of a global planetary ocean. This model takes into account compressibility, stratification, and sphericity terms, which are usually ignored in 2D approaches. An analytic solution is computed and used to study the dependence of the tidal response on the tidal frequency and on the ocean depth and stratification. Results. In the 2D asymptotic limit, we recover the frequency-resonant behaviour due to surface inertial-gravity waves identified by early studies. As the ocean depth and Brunt–Väisälä frequency increase, the contribution of internal gravity waves grows in importance and the tidal response becomes 3D. In the case of deep oceans, the stable stratification induces resonances that can increase the tidal dissipation rate by several orders of magnitude. It is thus able to significantly affect the evolution time scale of the planetary rotation.
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Clark, Elizabeth A., Justin Sheffield, Michelle T. H. van Vliet, Bart Nijssen e Dennis P. Lettenmaier. "Continental Runoff into the Oceans (1950–2008)". Journal of Hydrometeorology 16, n. 4 (29 luglio 2015): 1502–20. http://dx.doi.org/10.1175/jhm-d-14-0183.1.
Testo completoAbstract (sommario):
Abstract A common term in the continental and oceanic components of the global water cycle is freshwater discharge to the oceans. Many estimates of the annual average global discharge have been made over the past 100 yr with a surprisingly wide range. As more observations have become available and continental-scale land surface model simulations of runoff have improved, these past estimates are cast in a somewhat different light. In this paper, a combination of observations from 839 river gauging stations near the outlets of large river basins is used in combination with simulated runoff fields from two implementations of the Variable Infiltration Capacity land surface model to estimate continental runoff into the world’s oceans from 1950 to 2008. The gauges used account for ~58% of continental areas draining to the ocean worldwide, excluding Greenland and Antarctica. This study estimates that flows to the world’s oceans globally are 44 200 (±2660) km3 yr−1 (9% from Africa, 37% from Eurasia, 30% from South America, 16% from North America, and 8% from Australia–Oceania). These estimates are generally higher than previous estimates, with the largest differences in South America and Australia–Oceania. Given that roughly 42% of ocean-draining continental areas are ungauged, it is not surprising that estimates are sensitive to the land surface and hydrologic model (LSM) used, even with a correction applied to adjust for model bias. The results show that more and better in situ streamflow measurements would be most useful in reducing uncertainties, in particular in the southern tip of South America, the islands of Oceania, and central Africa.
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Bear, Christopher. "The ocean exceeded: Fish, flows and forces". Dialogues in Human Geography 9, n. 3 (27 settembre 2019): 329–32. http://dx.doi.org/10.1177/2043820619878567.
Testo completoAbstract (sommario):
The ongoing conceptualisation of oceans and the hydrosphere by Peters and Steinberg is to be welcomed. They continue to challenge geography’s historical tendency to focus on and from terrestrial spaces, exploring how oceans exceed their material, discursive and imagined boundaries along with their liquid form. This short commentary responds specifically to their assertion that ‘The ocean is fish’. Using the example of Atlantic salmon, it questions the directionality at the heart of Peters and Steinberg’s paper. It focuses particularly on the complex spatialities of salmonid life, and the ability of salmon to blur aquatic boundaries. The commentary argues that if oceans exceed, they are also exceeded, whether through the extra-planetary forces that guide salmonid migration and affect tides, or the inward flows of water from rivers. It ends by questioning the space given to non-human life in the more-than-wet ontology, asking how such actants might be implicated in oceanic excess, particularly when the ocean’s intrinsic voluminous excess renders them beyond human awareness or understanding.
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Kidd, Aline H., e Robert M. Kidd. "General Attitudes toward and Knowledge about the Importance of Ocean Life". Psychological Reports 82, n. 1 (febbraio 1998): 323–29. http://dx.doi.org/10.2466/pr0.1998.82.1.323.
Testo completoAbstract (sommario):
To evaluate the amount of awareness and quality of knowledge about ocean life the average American possesses 100 men and 100 women were asked what they knew about the importance of the oceans, their attitudes toward protection of marine life and oceanic ecology, and their sources of information regarding oceans. 98% believed that oceans are necessary for human survival and 92% believed that marine life was essential to the over-all ecology. 89% believed that dumping and toxic pollution almost irreparably harm marine life and that such practices must be stopped. 48% obtained their information about the oceans from formal educational programs and 95% from popular movies and documentary video programs. These data indicate that adults are quite aware of the continuing problems which threaten the survival of ocean life, although few have any suggestions about solving such problems.
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Smith, H. J. "OCEANS: Tracing Ocean Circulation". Science 288, n. 5474 (23 giugno 2000): 2097e—2099. http://dx.doi.org/10.1126/science.288.5474.2097e.
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Quirk, Genevieve, e Quentin Hanich. "Ocean Diplomacy: The Pacific Island Countries’ Campaign to the UN for an Ocean Sustainable Development Goal". Asia-Pacific Journal of Ocean Law and Policy 1, n. 1 (3 giugno 2016): 68–95. http://dx.doi.org/10.1163/24519391-00101005.
Testo completoAbstract (sommario):
In this article we examine how Pacific Island Countries (pics) successfully championed a stand-alone Ocean Sustainable Development Goal (sdg) goal at the United Nations (un). We analyse how the un Post-2015 development process provided pics with a unique opportunity to use their experience with collective diplomacy and regional oceans governance to propose this international goal. In this article we establish how pics’ national and regional quest to strengthen their sovereign rights over marine resources motivated their diplomatic efforts for an Ocean sdg. The campaign was a significant political achievement, positioning these Large Ocean Island States (lois) as global ocean guardians. We critically evaluate the effectiveness of the pics’ diplomatic campaign to secure an international commitment for an Ocean sdg. The pics’ advocacy for Goal 14 under Agenda 2030 has enhanced their political effectiveness in the un by improving their recognition by other States as leaders in oceans governance. We suggest their Ocean sdg campaign forms part of a distinct and continuing brand of oceans diplomacy from Oceania.
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Eperjesi, John R. "Imagined Oceans". Journal of Popular Music Studies 34, n. 1 (1 marzo 2022): 118–40. http://dx.doi.org/10.1525/jpms.2022.34.1.118.
Testo completoAbstract (sommario):
Over the past twenty years, Black Atlantic Afrofuturism has been the dominant theoretical frame for thinking about the significance of Drexciya’s aquatically themed techno music and mythology. Yet there have been few analyses of Drexciya from the perspective of ecology, of the ocean as a marine environment. Through a semiotic analysis of Drexciya’s 1993 EP Bubble Metropolis, this paper moves the discussion of Drexciya in the direction of ecocriticism and blue cultural studies, or more broadly, the blue humanities, in order to interpret the stories it tells about an imagined ocean. What do these stories mean? Why are these stories important now? Through the production and circulation of oceanic narratives that encourage listeners to imagine, wonder about, and groove to the ocean, Drexciya’s music and mythology can be understood as a form of “pre-emptive activism,” which designates indirect activist modes that inspire people to care about places, such as an ocean, that they take for granted or ignore. By imagining oceans full of sound, Drexciya fostered a tacit form of marine environmentalism in the 1990s. With oceanic ecosystems on the edge of collapse as a result of the climate emergency, all forms of marine activism, from the direct to the indirect, have gained a new sense of urgency. We need to listen to Drexciya now more than ever.
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Dommenget, Dietmar. "The Ocean’s Role in Continental Climate Variability and Change". Journal of Climate 22, n. 18 (15 settembre 2009): 4939–52. http://dx.doi.org/10.1175/2009jcli2778.1.
Testo completoAbstract (sommario):
Abstract A characteristic feature of global warming is the land–sea contrast, with stronger warming over land than over oceans. Recent studies find that this land–sea contrast also exists in equilibrium global change scenarios, and it is caused by differences in the availability of surface moisture over land and oceans. In this study it is illustrated that this land–sea contrast exists also on interannual time scales and that the ocean–land interaction is strongly asymmetric. The land surface temperature is more sensitive to the oceans than the oceans are to the land surface temperature, which is related to the processes causing the land–sea contrast in global warming scenarios. It suggests that the ocean’s natural variability and change is leading to variability and change with enhanced magnitudes over the continents, causing much of the longer-time-scale (decadal) global-scale continental climate variability. Model simulations illustrate that continental warming due to anthropogenic forcing (e.g., the warming at the end of the last century or future climate change scenarios) is mostly (80%–90%) indirectly forced by the contemporaneous ocean warming, not directly by local radiative forcing.
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Souza Neto, Pedro Fernandes de, Djane Fonseca Da Silva e Henrique Ravi Rocha de Carvalho Almeida. "Análise da Variabilidade Climática dos Oceanos Atlântico e Pacífico". Revista Brasileira de Geografia Física 14, n. 4 (2021): 1861–79. http://dx.doi.org/10.26848/rbgf.v14.4.p1861-1879.
Testo completoAbstract (sommario):
The sea surface temperature is one of the main variables for analyzing the global climate, and with that, it is essential to know its behavior. Thus, the objective of this study is to understand the best temperature variability of the sea surface of the Atlantic and Pacific oceans, through information on the causes of its variability using Wavelet analysis, and also using the climatic trends of the TSM of the oceans. Sea surface temperature anomaly data obtained through the National Oceanic and Atmospheric Administration with period of 1955-2018, for the Atlantic and Pacific Oceans, divided into sectors and some statistical analyzes were used. Using the wavelet analysis method, it was possible to observe the phenomena El Niño South Oscillation, Atlantic Dipole, sunspots and Pacific Decadal Oscillation, acting on the studied time series; however, the Pacific Decadal Oscillation, which occurs in the Pacific Ocean, proved to be a phenomenon of dominant time scale in the Atlantic and Pacific Oceans. The Mann-Kendall trend test showed a linear increase in the sea surface temperature anomaly for the two studied Oceans, and in both, the South sector has a greater increase than the North sector. Climate trends indicate that the Pacific Ocean is warming more than the Atlantic Ocean. It is also possible to conclude that the Southern sector of the two Oceans is heating up more than the Northern sector. The signs of the limit ranges for the averages of the southern sectors demonstrate greater variability of the anomalies at the South Atlantic and South Pacific. The Northern sector was more similar to the general basin, both in the Atlantic and the Pacific, proving the importance of continental areas for warming the oceans. These results were strengthened with those found by box plots and frequency distribution. The warming of the Pacific was also reinforced in all statistics mad.
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Renforth, P., e J. S. Campbell. "The role of soils in the regulation of ocean acidification". Philosophical Transactions of the Royal Society B: Biological Sciences 376, n. 1834 (4 agosto 2021): 20200174. http://dx.doi.org/10.1098/rstb.2020.0174.
Testo completoAbstract (sommario):
Soils play an important role in mediating chemical weathering reactions and carbon transfer from the land to the ocean. Proposals to increase the contribution of alkalinity to the oceans through ‘enhanced weathering’ as a means to help prevent climate change are gaining increasing attention. This would augment the existing connection between the biogeochemical function of soils and alkalinity levels in the ocean. The feasibility of enhanced weathering depends on the combined influence of what minerals are added to soils, the formation of secondary minerals in soils and the drainage regime, and the partial pressure of respired CO 2 around the dissolving mineral. Increasing the alkalinity levels in the ocean through enhanced weathering could help to ameliorate the effects of ocean acidification in two ways. First, enhanced weathering would slightly elevate the pH of drainage waters, and the receiving coastal waters. The elevated pH would result in an increase in carbonate mineral saturation states, and a partial reversal in the effects of elevated CO 2 . Second, the increase in alkalinity would help to replenish the ocean's buffering capacity by maintaining the ‘Revelle Factor’, making the oceans more resilient to further CO 2 emissions. However, there is limited research on the downstream and oceanic impacts of enhanced weathering on which to base deployment decisions. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.
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Kajtar, Jules B., Agus Santoso, Matthew H. England e Wenju Cai. "Indo-Pacific Climate Interactions in the Absence of an Indonesian Throughflow". Journal of Climate 28, n. 13 (1 luglio 2015): 5017–29. http://dx.doi.org/10.1175/jcli-d-14-00114.1.
Testo completoAbstract (sommario):
Abstract The Pacific and Indian Oceans are connected by an oceanic passage called the Indonesian Throughflow (ITF). In this setting, modes of climate variability over the two oceanic basins interact. El Niño–Southern Oscillation (ENSO) events generate sea surface temperature anomalies (SSTAs) over the Indian Ocean that, in turn, influence ENSO evolution. This raises the question as to whether Indo-Pacific feedback interactions would still occur in a climate system without an Indonesian Throughflow. This issue is investigated here for the first time using a coupled climate model with a blocked Indonesian gateway and a series of partially decoupled experiments in which air–sea interactions over each ocean basin are in turn suppressed. Closing the Indonesian Throughflow significantly alters the mean climate state over the Pacific and Indian Oceans. The Pacific Ocean retains an ENSO-like variability, but it is shifted eastward. In contrast, the Indian Ocean dipole and the Indian Ocean basinwide mode both collapse into a single dominant and drastically transformed mode. While the relationship between ENSO and the altered Indian Ocean mode is weaker than that when the ITF is open, the decoupled experiments reveal a damping effect exerted between the two modes. Despite the weaker Indian Ocean SSTAs and the increased distance between these and the core of ENSO SSTAs, the interbasin interactions remain. This suggests that the atmospheric bridge is a robust element of the Indo-Pacific climate system, linking the Indian and Pacific Oceans even in the absence of an Indonesian Throughflow.
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Arnold, S. R., D. V. Spracklen, S. Gebhardt, T. Custer, J. Williams, I. Peeken e S. Alvain. "Relationships between atmospheric organic compounds and air-mass exposure to marine biology". Environmental Chemistry 7, n. 3 (2010): 232. http://dx.doi.org/10.1071/en09144.
Testo completoAbstract (sommario):
Environmental context.The exchange of gases between the atmosphere and oceans impacts Earth’s climate. Over the remote oceans, marine emissions of organic species may have significant impacts on cloud properties and the atmosphere’s oxidative capacity. Quantifying these emissions and their dependence on ocean biology over the global oceans is a major challenge. Here we present a new method which relates atmospheric abundance of several organic chemicals over the South Atlantic Ocean to the exposure of air to ocean biology over several days before its sampling. Abstract.We have used a Lagrangian transport model and satellite observations of oceanic chlorophyll-a concentrations and phytoplankton community structure, to investigate relationships between air mass biological exposure and atmospheric concentrations of organic compounds over the remote South Atlantic Ocean in January and February 2007. Accounting for spatial and temporal exposure of air masses to chlorophyll from biologically active ocean regions upwind of the observation location produces significant correlations with atmospheric organohalogens, despite insignificant or smaller correlations using commonly applied in-situ chlorophyll. Strongest correlations (r = 0.42–0.53) are obtained with chlorophyll exposure over a 2-day transport history for CHBr3, CH2Br2, CH3I, and dimethylsulfide, and are strengthened further with exposure to specific phytoplankton types. Incorporating daylight and wind-speed terms into the chlorophyll exposure results in reduced correlations. The method demonstrates that conclusions drawn regarding oceanic trace-gas sources from in-situ chlorophyll or satellite chlorophyll averages over arbitrary areas may prove erroneous without accounting for the transport history of air sampled.
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Shimada, Teruhisa, Yuki Kanno e Toshiki Iwasaki. "Low-Level Cool Air over the Midlatitude Oceans in Summer". Journal of Climate 31, n. 5 (marzo 2018): 2075–90. http://dx.doi.org/10.1175/jcli-d-17-0188.1.
Testo completoAbstract (sommario):
The climatology of low-level cool air over the midlatitude oceans in summer is presented based on an isentropic analysis. This study focuses on isentropic surfaces of 296 K to analyze an adiabatic invariant referred to as the negative heat content representing the coldness of the air layer below the threshold isentropic surface. This approach allows a systematic analysis and a quantitative comparison of the cool air distribution and a diagnosis of diabatic heating of the air mass. The cool air covers most of the subarctic oceans and extends equatorward over the coastal upwelling regions in the east of the ocean basins. In these regions, the genesis of the cool air is diagnosed. The loss of the cool air occurs over land and the subtropical oceans, particularly on the offshore side of the coastal upwelling regions. In the Pacific sector and the Indian Ocean sector of the Southern Ocean, another large loss of the cool air occurs along the oceanic frontal zone including the Agulhas Return Current. Over the zonally extended region where the cool air is generated in the Southern Hemisphere and the coastal upwelling regions, it is suggested that diabatic cooling associated with low-level clouds overcome heating by turbulent surface heat fluxes. The genesis of the cool air over the subarctic oceans in the Northern Hemisphere in the warm season switches into the loss of the cold air in the cool season on a basin scale. Meanwhile, over the oceans in the Southern Hemisphere, there is no basin-scale seasonal switch.
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Brosche, P. "Oceanic Influences on the Angular Velocity of the Earth". Symposium - International Astronomical Union 141 (1990): 156. http://dx.doi.org/10.1017/s0074180900086617.
Testo completoAbstract (sommario):
Hydrodynamical computations of the major partial tides in the oceans have been evaluated for the changes both in moment of inertia and relative angular momentum due to ocean currents. If the system solid Earth plus oceans is seen as an isolated system for these time scales, the oceanic variations lead to mirror-like changes in the rotation of the solid Earth. Amplitudes are of the order of 0.1 ms in Universal time. In contrast to the effects of solid Earth tide, phases are away from equilibrium phases.
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Chisholm, S. W. "OCEANS: Dis-Crediting Ocean Fertilization". Science 294, n. 5541 (12 ottobre 2001): 309–10. http://dx.doi.org/10.1126/science.1065349.
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Malviya, Shruti, Eleonora Scalco, Stéphane Audic, Flora Vincent, Alaguraj Veluchamy, Julie Poulain, Patrick Wincker et al. "Insights into global diatom distribution and diversity in the world’s ocean". Proceedings of the National Academy of Sciences 113, n. 11 (29 febbraio 2016): E1516—E1525. http://dx.doi.org/10.1073/pnas.1509523113.
Testo completoAbstract (sommario):
Diatoms (Bacillariophyta) constitute one of the most diverse and ecologically important groups of phytoplankton. They are considered to be particularly important in nutrient-rich coastal ecosystems and at high latitudes, but considerably less so in the oligotrophic open ocean. The Tara Oceans circumnavigation collected samples from a wide range of oceanic regions using a standardized sampling procedure. Here, a total of ∼12 million diatom V9-18S ribosomal DNA (rDNA) ribotypes, derived from 293 size-fractionated plankton communities collected at 46 sampling sites across the global ocean euphotic zone, have been analyzed to explore diatom global diversity and community composition. We provide a new estimate of diversity of marine planktonic diatoms at 4,748 operational taxonomic units (OTUs). Based on the total assigned ribotypes, Chaetoceros was the most abundant and diverse genus, followed by Fragilariopsis, Thalassiosira, and Corethron. We found only a few cosmopolitan ribotypes displaying an even distribution across stations and high abundance, many of which could not be assigned with confidence to any known genus. Three distinct communities from South Pacific, Mediterranean, and Southern Ocean waters were identified that share a substantial percentage of ribotypes within them. Sudden drops in diversity were observed at Cape Agulhas, which separates the Indian and Atlantic Oceans, and across the Drake Passage between the Atlantic and Southern Oceans, indicating the importance of these ocean circulation choke points in constraining diatom distribution and diversity. We also observed high diatom diversity in the open ocean, suggesting that diatoms may be more relevant in these oceanic systems than generally considered.
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Thomas, H., L. S. Schiettecatte, K. Suykens, Y. J. M. Koné, E. H. Shadwick, A. E. F. Prowe, Y. Bozec, H. J. W. de Baar e A. V. Borges. "Enhanced ocean carbon storage from anaerobic alkalinity generation in coastal sediments". Biogeosciences Discussions 5, n. 4 (9 settembre 2008): 3575–91. http://dx.doi.org/10.5194/bgd-5-3575-2008.
Testo completoAbstract (sommario):
Abstract. The coastal ocean constitutes the crucial link between land, the open ocean and the atmosphere. Furthermore, its shallow water column permits close interactions between the sedimentary and atmospheric compartments, which otherwise are decoupled at short time scales (<1000 yr) in the open oceans. Despite the prominent role of the coastal oceans in absorbing atmospheric CO2 and transferring it into the deep oceans via the continental shelf pump, the underlying mechanisms remain only partly understood. Evaluating observations from the North Sea, a NW European shelf sea, we provide evidence that anaerobic degradation of organic matter, fuelled from land and ocean, generates alkalinity (AT) and increases the CO2 buffer capacity of seawater. At both the basin wide and annual scales anaerobic AT generation in the North Sea's tidal mud flat area irreversibly facilitates 7–10%, or taking into consideration benthic denitrification in the North Sea, 20–25% of the North Sea's overall CO2 uptake. At the global scale, anaerobic AT generation could be accountable for as much as 60% of the uptake of CO2 in shelf and marginal seas, making this process, the anaerobic pump, a key player in the biological carbon pump. Under future high CO2 conditions oceanic CO2 storage via the anaerobic pump may even gain further relevance because of stimulated ocean productivity.
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Losleben, Lisa Katrin, Monica Clerici, Villads Holm e Giuliana Panieri. "Cold seeps symphony". Septentrio Educational, n. 1 (28 aprile 2023): 40–46. http://dx.doi.org/10.7557/8.7051.
Testo completoAbstract (sommario):
Focus: To listen to the Arctic Ocean’s sounds and to learn about the Arctic Ocean’s biodiversity, particularly near cold seeps. We will experiment with creating new sound expressions inspired by the Ocean. For pupils with hearing impairment, pupils can create a bodily expression of this and/or use instruments they are comfortable with. Learning objectives: With this activity pupils will start to understand: The multitude of sounds audible in the Ocean and near to cold seeps at the sea-bed. That the oceans, including the Arctic Ocean, harbors great biodiversity. What an oceanographic ship is, and the anthropic sounds related to it. Key words: Ocean research, exploration, human/non-human relationship within ocean, sounds, place, noise.
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Voss, Maren, Hermann W. Bange, Joachim W. Dippner, Jack J. Middelburg, Joseph P. Montoya e Bess Ward. "The marine nitrogen cycle: recent discoveries, uncertainties and the potential relevance of climate change". Philosophical Transactions of the Royal Society B: Biological Sciences 368, n. 1621 (5 luglio 2013): 20130121. http://dx.doi.org/10.1098/rstb.2013.0121.
Testo completoAbstract (sommario):
The ocean's nitrogen cycle is driven by complex microbial transformations, including nitrogen fixation, assimilation, nitrification, anammox and denitrification. Dinitrogen is the most abundant form of nitrogen in sea water but only accessible by nitrogen-fixing microbes. Denitrification and nitrification are both regulated by oxygen concentrations and potentially produce nitrous oxide (N 2 O), a climate-relevant atmospheric trace gas. The world's oceans, including the coastal areas and upwelling areas, contribute about 30 per cent to the atmospheric N 2 O budget and are, therefore, a major source of this gas to the atmosphere. Human activities now add more nitrogen to the environment than is naturally fixed. More than half of the nitrogen reaches the coastal ocean via river input and atmospheric deposition, of which the latter affects even remote oceanic regions. A nitrogen budget for the coastal and open ocean, where inputs and outputs match rather well, is presented. Furthermore, predicted climate change will impact the expansion of the oceans' oxygen minimum zones, the productivity of surface waters and presumably other microbial processes, with unpredictable consequences for the cycling of nitrogen. Nitrogen cycling is closely intertwined with that of carbon, phosphorous and other biologically important elements via biological stoichiometric requirements. This linkage implies that human alterations of nitrogen cycling are likely to have major consequences for other biogeochemical processes and ecosystem functions and services.
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Ming, Wan. "Zheng He’s Seven Voyages into the Namoli Ocean–the Indian Ocean". China and Asia 1, n. 1 (11 febbraio 2019): 92–125. http://dx.doi.org/10.1163/2589465x-00101004.
Testo completoAbstract (sommario):
In the history of the development of human civilization, the Silk Road has been an important route of traffic and exchange between the East and the West. From Zhang Qian’s 張騫 opening up of the Silk Road across the Western Regions (Xiyue 西域) to Zheng He’s 鄭和 sailing to the Western Oceans (xia xiyang 下西洋) more than 1500 years later, China had a continuous desire to explore beyond its borders. At the time of Zheng He, the term “Western Oceans” (xiyang 西洋) had a specific meaning. As shown by the account of Ma Huan 馬歡, who personally joined Zheng He on the voyages, the people of Ming China considered the “Western Oceans” to be the Namoli Ocean (Namoli yang 那没黎洋), later called the Indian Ocean. Thus, it could be concluded that the Western Oceans where Zheng He’s fleet went meant the Indian Ocean. Even today most scholars still divide the Eastern and Western Oceans at Brunei, with no clear understanding of where the Western Oceans to which Zheng He sailed were actually located. It is therefore important to make clear that the Western Oceans in his time referred to the Indian Ocean, before moving on to investigate the purpose of the voyages and related historical issues. Even more important is to point out that Zheng He’s expeditions in the early fifteenth century reflected that Chinese people took to the seas on a scale larger than ever before and joined the maritime and overland silk routes together. The place where this occurred was the Indian Ocean.
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Stewart, Kial D., e Thomas W. N. Haine. "Thermobaricity in the Transition Zones between Alpha and Beta Oceans". Journal of Physical Oceanography 46, n. 6 (giugno 2016): 1805–21. http://dx.doi.org/10.1175/jpo-d-16-0017.1.
Testo completoAbstract (sommario):
AbstractThe role of the ocean in Earth’s climate is fundamentally influenced by the locally dominant stratifying property (heat or salt), which in turn can be used to categorize the ocean into three classes: alpha, beta, and transition zone oceans. Alpha and beta oceans are regions where the stratification is permanently set by heat and salt, respectively. Transition zone oceans exist between alpha and beta oceans and are regions where the stratification is seasonally or intermittently set by heat or salt. Despite their large ranges of temperature and salinity, transition zone oceans are the most weakly stratified regions of the upper oceans, making them ideal locations for thermobaric effects arising from the nonlinear equation of state of seawater. Here a novel definition and quantification of alpha, beta, and transition zone oceans is presented and used to analyze 4 years (2010–13) of hydrographic data developed from the Argo profiling float array. Two types of thermobaric instabilities are defined and identified in the hydrographic data. The first type arises from the vertical relocation of individual water parcels. The second type is novel and relates to the effect of pressure on the stratification through the pressure dependence of the thermal expansion coefficient; water that is stably stratified for one pressure is not necessarily stable for other pressures. The upper 1500 m of the global ocean is composed of 67% alpha, 15% beta, and 17% transition zone oceans, with 5.7% identified as thermobarically unstable. Over 63% of these thermobarically unstable waters exist in transition zone oceans, suggesting that these are important locations for efficient vertical transport of water-mass properties.
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Prados-Roman, C., C. A. Cuevas, R. P. Fernandez, D. E. Kinnison, J. F. Lamarque e A. Saiz-Lopez. "A negative feedback between anthropogenic ozone pollution and enhanced ocean emissions of iodine". Atmospheric Chemistry and Physics Discussions 14, n. 15 (27 agosto 2014): 21917–42. http://dx.doi.org/10.5194/acpd-14-21917-2014.
Testo completoAbstract (sommario):
Abstract. Naturally emitted from the oceans, iodine compounds efficiently destroy atmospheric ozone and reduce its positive radiative forcing effects in the troposphere. Emissions of inorganic iodine have been experimentally shown to depend on the deposition to the oceans of tropospheric ozone, whose concentrations have significantly increased since 1850 as a result of human activities. A chemistry-climate model is used herein to quantify the current ocean emissions of inorganic iodine and assess the impact that the anthropogenic increase of tropospheric ozone has had on the natural cycle of iodine in the marine environment since pre-industrial times. Our results indicate that the human-driven enhancement of tropospheric ozone has doubled the oceanic inorganic iodine emissions following the reaction of ozone with iodide at the sea surface. The consequent build-up of atmospheric iodine, with maximum enhancements of up to 70% with respect to preindustrial times in continental pollution outflow regions, has in turn accelerated the ozone chemical loss over the oceans with strong spatial patterns. We suggest that this ocean–atmosphere interaction represents a negative geochemical feedback loop by which current ocean emissions of iodine act as a natural buffer for ozone pollution and its radiative forcing in the global marine environment.
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Prados-Roman, C., C. A. Cuevas, R. P. Fernandez, D. E. Kinnison, J.-F. Lamarque e A. Saiz-Lopez. "A negative feedback between anthropogenic ozone pollution and enhanced ocean emissions of iodine". Atmospheric Chemistry and Physics 15, n. 4 (27 febbraio 2015): 2215–24. http://dx.doi.org/10.5194/acp-15-2215-2015.
Testo completoAbstract (sommario):
Abstract. Naturally emitted from the oceans, iodine compounds efficiently destroy atmospheric ozone and reduce its positive radiative forcing effects in the troposphere. Emissions of inorganic iodine have been experimentally shown to depend on the deposition to the oceans of tropospheric ozone, whose concentrations have significantly increased since 1850 as a result of human activities. A chemistry–climate model is used herein to quantify the current ocean emissions of inorganic iodine and assess the impact that the anthropogenic increase in tropospheric ozone has had on the natural cycle of iodine in the marine environment since pre-industrial times. Our results indicate that the human-driven enhancement of tropospheric ozone has doubled the oceanic inorganic iodine emissions following the reaction of ozone with iodide at the sea surface. The consequent build-up of atmospheric iodine, with maximum enhancements of up to 70% with respect to pre-industrial times in continental pollution outflow regions, has in turn accelerated the ozone chemical loss over the oceans with strong spatial patterns. We suggest that this ocean–atmosphere interaction represents a negative geochemical feedback loop by which current ocean emissions of iodine act as a natural buffer for ozone pollution and its radiative forcing in the global marine environment.
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Watson, Andrew J., Timothy M. Lenton e Benjamin J. W. Mills. "Ocean deoxygenation, the global phosphorus cycle and the possibility of human-caused large-scale ocean anoxia". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 375, n. 2102 (7 agosto 2017): 20160318. http://dx.doi.org/10.1098/rsta.2016.0318.
Testo completoAbstract (sommario):
The major biogeochemical cycles that keep the present-day Earth habitable are linked by a network of feedbacks, which has led to a broadly stable chemical composition of the oceans and atmosphere over hundreds of millions of years. This includes the processes that control both the atmospheric and oceanic concentrations of oxygen. However, one notable exception to the generally well-behaved dynamics of this system is the propensity for episodes of ocean anoxia to occur and to persist for 10 5 –10 6 years, these ocean anoxic events (OAEs) being particularly associated with warm ‘greenhouse’ climates. A powerful mechanism responsible for past OAEs was an increase in phosphorus supply to the oceans, leading to higher ocean productivity and oxygen demand in subsurface water. This can be amplified by positive feedbacks on the nutrient content of the ocean, with low oxygen promoting further release of phosphorus from ocean sediments, leading to a potentially self-sustaining condition of deoxygenation. We use a simple model for phosphorus in the ocean to explore this feedback, and to evaluate the potential for humans to bring on global-scale anoxia by enhancing P supply to the oceans. While this is not an immediate global change concern, it is a future possibility on millennial and longer time scales, when considering both phosphate rock mining and increased chemical weathering due to climate change. Ocean deoxygenation, once begun, may be self-sustaining and eventually could result in long-lasting and unpleasant consequences for the Earth's biosphere. This article is part of the themed issue ‘Ocean ventilation and deoxygenation in a warming world’.
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Thomas, H., L. S. Schiettecatte, K. Suykens, Y. J. M. Koné, E. H. Shadwick, A. E. F. Prowe, Y. Bozec, H. J. W. de Baar e A. V. Borges. "Enhanced ocean carbon storage from anaerobic alkalinity generation in coastal sediments". Biogeosciences 6, n. 2 (25 febbraio 2009): 267–74. http://dx.doi.org/10.5194/bg-6-267-2009.
Testo completoAbstract (sommario):
Abstract. The coastal ocean is a crucial link between land, the open ocean and the atmosphere. The shallowness of the water column permits close interactions between the sedimentary, aquatic and atmospheric compartments, which otherwise are decoupled at long time scales (≅ 1000 yr) in the open oceans. Despite the prominent role of the coastal oceans in absorbing atmospheric CO2 and transferring it into the deep oceans via the continental shelf pump, the underlying mechanisms remain only partly understood. Evaluating observations from the North Sea, a NW European shelf sea, we provide evidence that anaerobic degradation of organic matter, fuelled from land and ocean, generates total alkalinity (AT) and increases the CO2 buffer capacity of seawater. At both the basin wide and annual scales anaerobic AT generation in the North Sea's tidal mud flat area irreversibly facilitates 7–10%, or taking into consideration benthic denitrification in the North Sea, 20–25% of the North Sea's overall CO2 uptake. At the global scale, anaerobic AT generation could be accountable for as much as 60% of the uptake of CO2 in shelf and marginal seas, making this process, the anaerobic pump, a key player in the biological carbon pump. Under future high CO2 conditions oceanic CO2 storage via the anaerobic pump may even gain further relevance because of stimulated ocean productivity.
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Waugh, Darryn W., Francois Primeau, Tim DeVries e Mark Holzer. "Recent Changes in the Ventilation of the Southern Oceans". Science 339, n. 6119 (31 gennaio 2013): 568–70. http://dx.doi.org/10.1126/science.1225411.
Testo completoAbstract (sommario):
Surface westerly winds in the Southern Hemisphere have intensified over the past few decades, primarily in response to the formation of the Antarctic ozone hole, and there is intense debate on the impact of this on the ocean's circulation and uptake and redistribution of atmospheric gases. We used measurements of chlorofluorocarbon-12 (CFC-12) made in the southern oceans in the early 1990s and mid- to late 2000s to examine changes in ocean ventilation. Our analysis of the CFC-12 data reveals a decrease in the age of subtropical subantarctic mode waters and an increase in the age of circumpolar deep waters, suggesting that the formation of the Antarctic ozone hole has caused large-scale coherent changes in the ventilation of the southern oceans.
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Rajan, Kanna, Fernando Aguado, Pierre Lermusiaux, João Borges de Sousa, Ajit Subramaniam e Joaquin Tintore. "METEOR: A Mobile (Portable) ocEan roboTic ObsErvatORy". Marine Technology Society Journal 55, n. 3 (1 maggio 2021): 74–75. http://dx.doi.org/10.4031/mtsj.55.3.42.
Testo completoAbstract (sommario):
Abstract The oceans make this planet habitable and provide a variety of essential ecosystem services ranging from climate regulation through control of greenhouse gases to provisioning about 17% of protein consumed by humans. The oceans are changing as a consequence of human activity but this system is severely under sampled. Traditional methods of studying the oceans, sailing in straight lines, extrapolating a few point measurements have not changed much in 200 years. Despite the tremendous advances in sampling technologies, we often use our autonomous assets the same way. We propose to use the advances in multiplatform, multidisciplinary, and integrated ocean observation, artificial intelligence, marine robotics, new high-resolution coastal ocean data assimilation techniques and computer models to observe and predict the oceans “intelligently”—by deploying self-propelled autonomous sensors and Smallsats guided by data assimilating models to provide observations to reduce model uncertainty in the coastal ocean. This system will be portable and capable of being deployed rapidly in any ocean.
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Takahashi, J., Y. Itoh, T. Matsuo, Y. Oasa, Y. P. Bach e M. Ishiguro. "Polarimetric signature of the oceans as detected by near-infrared Earthshine observations". Astronomy & Astrophysics 653 (settembre 2021): A99. http://dx.doi.org/10.1051/0004-6361/202039331.
Testo completoAbstract (sommario):
Context. The discovery of an extrasolar planet with an ocean has crucial importance in the search for life beyond Earth. The polarimetric detection of specularly reflected light from a smooth liquid surface is anticipated theoretically, though the polarimetric signature of Earth’s oceans has not yet been conclusively detected in disk-integrated planetary light. Aims. We aim to detect and measure the polarimetric signature of the Earth’s oceans. Methods. We conducted near-infrared polarimetry for lunar Earthshine and collected data on 32 nights with a variety of ocean fractions in the Earthshine-contributing region. Results. A clear positive correlation was revealed between the polarization degree and ocean fraction. We found hourly variations in polarization in accordance with rotational transition of the ocean fraction. The ratios of the variation to the typical polarization degree were as large as ~0.2–1.4. Conclusions. Our observations provide plausible evidence of the polarimetric signature attributed to Earth’s oceans. Near-infrared polarimetry may be considered a prospective technique in the search for exoplanetary oceans.
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Nakayama, A., T. Kodama, M. Ikoma e Y. Abe. "Runaway climate cooling of ocean planets in the habitable zone: a consequence of seafloor weathering enhanced by melting of high-pressure ice". Monthly Notices of the Royal Astronomical Society 488, n. 2 (3 luglio 2019): 1580–96. http://dx.doi.org/10.1093/mnras/stz1812.
Testo completoAbstract (sommario):
ABSTRACT Terrestrial planets covered globally with thick oceans (termed ocean planets) in the habitable zone were previously inferred to have extremely hot climates in most cases. This is because H2O high-pressure (HP) ice on the seafloor prevents chemical weathering and, thus, removal of atmospheric CO2. Previous studies, however, ignored melting of the HP ice and horizontal variation in heat flux from oceanic crusts. Here, we examine whether high heat fluxes near the mid-ocean ridge melt the HP ice and thereby remove atmospheric CO2. We develop integrated climate models of an Earth-size ocean planet with plate tectonics for different ocean masses, which include the effects of HP ice melting, seafloor weathering, and the carbonate–silicate geochemical carbon cycle. We find that the heat flux near the mid-ocean ridge is high enough to melt the ice, enabling seafloor weathering. In contrast to the previous theoretical prediction, we show that climates of terrestrial planets with massive oceans lapse into extremely cold ones (or snowball states) with CO2-poor atmospheres. Such extremely cold climates are achieved mainly because the HP ice melting fixes seafloor temperature at the melting temperature, thereby keeping a high weathering flux regardless of surface temperature. We estimate that ocean planets with oceans several tens of the Earth’s ocean mass no longer maintain temperate climates. These results suggest that terrestrial planets with extremely cold climates exist even in the habitable zone beyond the Solar system, given the frequency of water-rich planets predicted by planet formation theories.
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Ishida, Akio, Yoshikazu Sasai e Yasuhiro Yamanaka. "Role of Eddies in Chlorofluorocarbon Transport in Wind-Driven Oceanic Layers". Journal of Physical Oceanography 37, n. 10 (1 ottobre 2007): 2491–508. http://dx.doi.org/10.1175/jpo3125.1.
Testo completoAbstract (sommario):
Abstract In this study the global distribution and transport of chlorofluorocarbons (CFCs) in the oceans are investigated using a high-resolution numerical model. The authors focus on the effects of wind-driven processes such as subduction and ventilation on the distribution of CFC-11 within surface and thermocline layers. Local maxima of tracer inventory are identified in oceanic regions. Two major absorption regions in the South Pacific Ocean are located west of South America and northeast of New Zealand in boundary latitudes between subtropical and subantarctic areas. In the North Pacific and south Indian Oceans, the positions of the local maxima of tracers migrate west–east with increasing density. The relationship between water formation and tracer distribution is discussed by comparing the wintertime mixed layer depth and mean circulation. The contributions of mean and eddy transport of the meridional overturning cells to tracer transport are analyzed. Stationary eddies have a large impact in the Southern Ocean, while transient eddies are crucial for the compensation of mean transport in the equatorial oceans. Mean and seasonal variability components of meridional tracer transport are dominant in the subtropics; however, eddy transport also plays a significant role.
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Visser, A. W. "OCEAN SCIENCE: Biomixing of the Oceans?" Science 316, n. 5826 (11 maggio 2007): 838–39. http://dx.doi.org/10.1126/science.1141272.
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Hegerl, G. C. "OCEAN SCIENCE: Warming the World's Oceans". Science 309, n. 5732 (8 luglio 2005): 254–55. http://dx.doi.org/10.1126/science.1114456.
Testo completo
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Haward, Marcus. "National ocean governance and sustainable oceans". Australian Journal of Maritime & Ocean Affairs 8, n. 4 (ottobre 2016): 267–68. http://dx.doi.org/10.1080/18366503.2016.1254897.
Testo completo
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Holmes, Thomas M., Zanna Chase, Pier van der Merwe, Ashley T. Townsend e Andrew R. Bowie. "Detection, dispersal and biogeochemical contribution of hydrothermal iron in the ocean". Marine and Freshwater Research 68, n. 12 (2017): 2184. http://dx.doi.org/10.1071/mf16335.
Testo completoAbstract (sommario):
This review aims to bring into focus the current understanding of hydrothermal systems and plume dynamics, tracers of hydrothermalism and the contribution of iron from hydrothermal vents to the global oceanic iron budget. The review then explores hydrothermal effect on surface ocean productivity. It is now well documented that scarcity of iron limits the production of chlorophyll-producing organisms in many regions of the ocean that are high in macronutrients. However, it is only recently that hydrothermal inputs have gained recognition as a source of Fe to the deep oceans that may potentially affect surface ocean productivity in some regions. A compilation of iron measurements from hydrothermal vents reveals that although hydrothermal studies measuring iron have increased significantly in recent years, there is still a dearth of data below 40°S. New analytical approaches for tracing iron sources, coupled with increasing sampling coverage of the oceans, is quickly improving knowledge of the effect of hydrothermal sources on biogeochemical cycles, a vital component in predicting future climate scenarios.
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Marinha, Marcelo Diniz Santa, Danian S. Oliveira, Paulo Eduardo Miranda Cunha e Luiz Gallisa Guimarães. "DISCRETE AIRY BEAM PROPAGATION IN DEEP OCEANS". Revista Brasileira de Geofísica 36, n. 4 (21 dicembre 2018): 1. http://dx.doi.org/10.22564/rbgf.v36i4.1969.
Testo completoAbstract (sommario):
ABSTRACT. In this work, based on the theory of modal propagation of acoustic energy in deep oceans and using the analogy between acoustics and quantum mechanics, we show that it is possible the existence of almost dispersionless Airy beams propagation at great distances with simultaneous wave packet shape preservation.Keywords: Normal modes, wave propagation, ocean acoustics, Airy beam.RESUMO. Neste trabalho, baseado na teoria de propagação da energia acústica por modos em oceanos profundos, mostraremos que é possível a existência de feixes de Airy que se propagam em grandes distâncias, com pouca dispersão da energia acústica e preservação de sua formaPalavras-chave: Modos normais, propagação de ondas, acústica oceanográfica, feixe de Airy.
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Ghosal, Abhisek. "Precarious Oceans and Vulnerability: Micropolitics of Care in Romesh Gunesekera’s Reef". Southeast Asian Review of English 61, n. 1 (1 luglio 2024): 80–102. http://dx.doi.org/10.22452/sare.vol61no1.6.
Testo completoAbstract (sommario):
Inoperative grammatology of post(g)locality followed by the incremental desires of neoliberal elites to marketize abundant oceanic resources scattered across the world renders the oceans extremely vulnerable—an appalling phenomenon which at once lays bare the vulnerability of the oceans conditioned by the strands of ‘precariousness’ and at times calls for the actualization of ‘micropolitics of care’—an ethically sound exercise which seems to be able to hold the oceans back from being economically subjected to the predatory ‘faces’ of contemporary neoliberal precarity. In this context, Romesh Gunesekera’s Reef is critically taken up to examine the rapid disappearance of coral reefs along with the illegal marketing of endangered marine species like dolphin so as to make readers aware of how the ocean stands at risk and moreover to put literary emphasis on the enactment of ‘micropolitics of care’ which seems to be able to effectively take on the wicked designs of contemporary neoliberal precarity for the greater sake of planetary consciousness.
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Rovira-Navarro, Marc, Isamu Matsuyama e Hamish C. F. C. Hay. "Thin-shell Tidal Dynamics of Ocean Worlds". Planetary Science Journal 4, n. 2 (1 febbraio 2023): 23. http://dx.doi.org/10.3847/psj/acae9a.
Testo completoAbstract (sommario):
Abstract Several solar system moons harbor subsurface water oceans; extreme internal heating or solar irradiation can form magma oceans in terrestrial bodies. Tidal forces drive ocean currents, producing tidal heating that affects the thermal−orbital evolution of these worlds. If the outermost layers (ocean and overlying shell) are thin, tidal dynamics can be described using thin-shell theory. Previous work assumed that the ocean and shell's thickness and density are uniform. We present a formulation of thin-shell dynamics that relaxes these assumptions and apply it to several cases of interest. The tidal response of unstratified oceans of constant thickness is given by surface gravity and Rossby waves, which can resonate with the tidal force. The oceans of the outer solar system are too thick for gravity wave resonances, but high-amplitude Rossby waves can be excited in moons with high orbital obliquity. We find that meridional ocean thickness variations hinder the excitation of Rossby waves, decreasing tidal dissipation and increasing the inclination damping timescale, which allows us to reconcile the present inclination of the Moon with the existence of a past long-lived magma ocean and to explain the inclination of Titan and Callisto without invoking a recent excitation. Stratified oceans can support internal gravity waves. We show that dissipation due to internal waves can exceed that resulting from surface gravity waves. For Enceladus, it can be close to the moon’s thermal output, even if the ocean is weakly stratified. Shear due to internal waves can result in Kelvin–Helmholtz instabilities and induce ocean mixing.
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Xie, Le, Wei Wei, Lanlan Cai, Xiaowei Chen, Yuhong Huang, Nianzhi Jiao, Rui Zhang e Ya-Wei Luo. "A global viral oceanography database (gVOD)". Earth System Science Data 13, n. 3 (24 marzo 2021): 1251–71. http://dx.doi.org/10.5194/essd-13-1251-2021.
Testo completoAbstract (sommario):
Abstract. Virioplankton are a key component of the marine biosphere in maintaining diversity of microorganisms and stabilizing ecosystems. They also contribute greatly to nutrient cycles/cycling by releasing organic matter after lysis of hosts. In this study, we constructed the first global viral oceanography database (gVOD) by collecting 10 931 viral abundance (VA) data and 727 viral production (VP) data, along with host and relevant oceanographic parameters when available. Most VA data were obtained in the North Atlantic (32 %) and North Pacific (29 %) oceans, while the southeast Pacific and Indian oceans were quite undersampled. The VA in the global ocean was 1.17(±3.31)×107 particles mL−1. The lytic and lysogenic VP in the global ocean was 9.87(±24.16)×105 and 2.53(±8.64)×105 particlesmL-1h-1, respectively. Average VA in coastal oceans was higher than that in surface open oceans (3.61(±6.30)×107 versus 0.73(±1.24)×107 particles mL−1), while average VP in coastal and surface open oceans was close. Vertically, VA, lytic VP and lysogenic VP deceased from surface to deep oceans by about 1 order of magnitude. The total number of viruses in the global ocean estimated by bin-averaging and the random forest method was 1.56×1030 and 1.49×1030 particles, leading to an estimate of global ocean viral biomass at 35.9 and 34.4 Tg C, respectively. We expect that the gVOD will be a fundamental and very useful database for laboratory, field and modeling studies in marine ecology and biogeochemistry. The full gVOD database (Xie et al., 2020) is stored in PANGAEA (https://doi.org/10.1594/PANGAEA.915758).
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Liu, Chuntao, Shoichi Shige, Yukari N. Takayabu e Edward Zipser. "Latent Heating Contribution from Precipitation Systems with Different Sizes, Depths, and Intensities in the Tropics". Journal of Climate 28, n. 1 (31 dicembre 2014): 186–203. http://dx.doi.org/10.1175/jcli-d-14-00370.1.
Testo completoAbstract (sommario):
Abstract Latent heating (LH) from precipitation systems with different sizes, depths, and convective intensities is quantified with 15 years of LH retrievals from version 7 Precipitation Radar (PR) products of the Tropical Rainfall Measuring Mission (TRMM). Organized precipitation systems, such as mesoscale convective systems (MCSs; precipitation area > 2000 km2), contribute to 88% of the LH above 7 km over tropical land and 95% over tropical oceans. LH over tropical land is mainly from convective precipitation, and has one vertical mode with a peak from 4 to 7 km. There are two vertical modes of LH over tropical oceans. The shallow mode from about 1 to 4 km results from small, shallow, and weak precipitation systems, and partially from congestus clouds with radar echo top between 5 and 8 km. The deep mode from 5 to 9 km is mainly from stratiform precipitation in MCSs. MCSs of different regions and seasons have different LH vertical structure mainly due to the different proportion of stratiform precipitation. MCSs over ocean have a larger fraction of stratiform precipitation and a top-heavy LH structure. MCSs over land have a higher percentage of convective versus stratiform precipitation, which results in a relatively lower-level peak in LH compared to MCSs over the ocean. MCSs during monsoons have properties of LH in between those typical land and oceanic MCSs. Consistent with the diurnal variation of precipitation, tropical land has a stronger LH diurnal variation than tropical oceans with peak LH in the late afternoon. Over tropical oceans in the early morning, the shallow mode of LH peaks slightly earlier than the deep mode. There are almost no diurnal changes of MCSs LH over oceans. However, the small convective systems over land contribute a significant amount of LH at all vertical levels in the afternoon, when the contribution of MCSs is small.
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Torma, Franziska. "Frontiers of Visibility". Transfers 3, n. 2 (1 giugno 2013): 24–46. http://dx.doi.org/10.3167/trans.2013.030203.
Testo completoAbstract (sommario):
This article deals with the history of underwater film and the role that increased mobility plays in the exploration of nature. Drawing on research on the exploration of the ocean, it analyzes the production of popular images of the sea. The entry of humans into the depths of the oceans in the twentieth century did not revitalize myths of mermaids but rather retold oceanic myths in a modern fashion. Three stages stand out in this evolution of diving mobility. In the 1920s and 1930s, scenes of divers walking under water were the dominant motif. From the 1940s to the 1960s, use of autonomous diving equipment led to a modern incarnation of the “mermen“ myth. From the 1950s to the 1970s, cinematic technology was able to create visions of entire oceanic ecosystems. Underwater films contributed to the period of machine-age exploration in a very particular way: they made virtual voyages of the ocean possible and thus helped to shape the current understanding of the oceans as part of Planet Earth.
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Yuliantiningsih, Aryuni, Hartiwiningsih, Ade Maman Suherman e Emmy Latifah. "Law and Justice for the Oceans: Study on Illegal, Unreported and Unregulated Fishing and Related Crimes". E3S Web of Conferences 47 (2018): 06006. http://dx.doi.org/10.1051/e3sconf/20184706006.
Testo completoAbstract (sommario):
This article examined the ethical and moral dimensions of Illegal, Unreported and Unregulated fishing and related crimes and explores the means to realize justice for the oceans. It needed a new paradigm for addressing the issues. The methods of discussion used statute approach and philosophical approach. Based on the research, it was known that IUU fishing related to other crimes and Transnational Organized Crime, so it was necessary to recognize the concept of transnational organized fisheries crime. The IPOA-IUU fishing and UNCLOS 1982 were not adequate to counter it. In the terms of ethics and morals, IUU fishing had violated the ecosystems ethics, the principles of sustainability, values of respect for human rights and justice for the oceans. Justice for the oceans can be realized with recognition of the ocean rights. It meant, the oceans was recognized had the equal position with humans. The oceans needed space to breathe and to breed for recovery itself. The legal consequences of the recognition of oceans rights, among others, extended the legal standing. It provided sanctions for perpetrators and provided obligations for States to protect the ocean rights.
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Sainger, Garima. "Microplastic Pollution in Oceans: A Barrier to Achieve Low Carbon Society". IOP Conference Series: Earth and Environmental Science 1279, n. 1 (1 dicembre 2023): 012021. http://dx.doi.org/10.1088/1755-1315/1279/1/012021.
Testo completoAbstract (sommario):
Abstract A society is known as low carbon society where individuals cut down the amount of carbon dioxide (CO2) emissions generated from different human activities without affecting any development needs. The increasing presence of carbon emissions has increased the need for urgent actions in this regard. To mitigate the effect of climate change ocean’s contribution is remarkable. But humans are treating oceans to dispose of their waste, which is affecting the ocean’s capacity of carbon sequestration. Out of all the pollution entering into oceans, (micro) plastic pollution is the most observable impacting the ocean’s capacity of carbon absorption. The evitable exposure of microplastics in oceans emphasized the need to know about the harmful effect of microplastics and measure to control them. Therefore, this review primarily focuses to define the role of oceans in achieving low carbon society and how microplastic is acting as a barrier to reduce oceans capacity to absorb and process atmospheric carbon into oxygen. The measures such as less use of plastic in production, education and awareness about the use of eco-friendly usages and activities, life cycle assessment and less consumption of plastic and strategic waste management method, recycling, and waste-to-energy recovery were suggested to solve the global problem of microplastics pollution.
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Lauro, Federico M., Diane McDougald, Torsten Thomas, Timothy J. Williams, Suhelen Egan, Scott Rice, Matthew Z. DeMaere et al. "The genomic basis of trophic strategy in marine bacteria". Proceedings of the National Academy of Sciences 106, n. 37 (8 settembre 2009): 15527–33. http://dx.doi.org/10.1073/pnas.0903507106.
Testo completoAbstract (sommario):
Many marine bacteria have evolved to grow optimally at either high (copiotrophic) or low (oligotrophic) nutrient concentrations, enabling different species to colonize distinct trophic habitats in the oceans. Here, we compare the genome sequences of two bacteria,Photobacterium angustumS14 andSphingopyxis alaskensisRB2256, that serve as useful model organisms for copiotrophic and oligotrophic modes of life and specifically relate the genomic features to trophic strategy for these organisms and define their molecular mechanisms of adaptation. We developed a model for predicting trophic lifestyle from genome sequence data and tested >400,000 proteins representing >500 million nucleotides of sequence data from 126 genome sequences with metagenome data of whole environmental samples. When applied to available oceanic metagenome data (e.g., the Global Ocean Survey data) the model demonstrated that oligotrophs, and not the more readily isolatable copiotrophs, dominate the ocean's free-living microbial populations. Using our model, it is now possible to define the types of bacteria that specific ocean niches are capable of sustaining.
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Goswami, A., P. L. Olson, L. A. Hinnov e A. Gnanadesikan. "OESbathy version 1.0: a method for reconstructing ocean bathymetry with realistic continental shelf-slope-rise structures". Geoscientific Model Development Discussions 8, n. 4 (2 aprile 2015): 3079–115. http://dx.doi.org/10.5194/gmdd-8-3079-2015.
Testo completoAbstract (sommario):
Abstract. We present a method for reconstructing global ocean bathymetry that uses a plate cooling model for the oceanic lithosphere, the age distribution of the oceanic crust, global oceanic sediment thicknesses, plus shelf-slope-rise structures calibrated at modern active and passive continental margins. Our motivation is to reconstruct realistic ocean bathymetry based on parameterized relationships of present-day variables that can be applied to global oceans in the geologic past, and to isolate locations where anomalous processes such as mantle convection may affect bathymetry. Parameters of the plate cooling model are combined with ocean crustal age to calculate depth-to-basement. To the depth-to-basement we add an isostatically adjusted, multicomponent sediment layer, constrained by sediment thickness in the modern oceans and marginal seas. A continental shelf-slope-rise structure completes the bathymetry reconstruction, extending from the ocean crust to the coastlines. Shelf-slope-rise structures at active and passive margins are parameterized using modern ocean bathymetry at locations where a complete history of seafloor spreading is preserved. This includes the coastal regions of the North, South, and Central Atlantic Ocean, the Southern Ocean between Australia and Antarctica, and the Pacific Ocean off the west coast of South America. The final products are global maps at 0.1° × 0.1° resolution of depth-to-basement, ocean bathymetry with an isostatically adjusted, multicomponent sediment layer, and ocean bathymetry with reconstructed continental shelf-slope-rise structures. Our reconstructed bathymetry agrees with the measured ETOPO1 bathymetry at most passive margins, including the east coast of North America, north coast of the Arabian Sea, and northeast and southeast coasts of South America. There is disagreement at margins with anomalous continental shelf-slope-rise structures, such as around the Arctic Ocean, the Falkland Islands, and Indonesia.
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Chenin, Pauline, Suzanne Picazo, Suzon Jammes, Gianreto Manatschal, Othmar Müntener e Garry Karner. "Potential role of lithospheric mantle composition in the Wilson cycle: a North Atlantic perspective". Geological Society, London, Special Publications 470, n. 1 (6 marzo 2018): 157–72. http://dx.doi.org/10.1144/sp470.10.
Testo completoAbstract (sommario):
AbstractAlthough the Wilson cycle is usually considered in terms of wide oceans floored with normal oceanic crust, numerous orogens result from the closure of embryonic oceans. We discuss how orogenic and post-orogenic processes may be controlled by the size/maturity of the inverted basin. We focus on the role of lithospheric mantle in controlling deformation and the magmatic budget. We describe the physical properties (composition, density, rheology) of three types of mantle: inherited, fertilized and depleted oceanic mantle. By comparing these, we highlight that fertilized mantle underlying embryonic oceans is mechanically weaker, less dense and more fertile than other types of mantle. We suggest that orogens resulting from the closure of a narrow, immature extensional system are essentially controlled by mechanical processes without significant thermal and lithological modification. The underlying mantle is fertile and thus has a high potential for magma generation during subsequent tectonic events. Conversely, the thermal state and lithology of orogens resulting from the closure of a wide, mature ocean are largely modified by subduction-related arc magmatism. The underlying mantle wedge is depleted, which may inhibit magma generation during post-orogenic extension. These end-member considerations are supported by observations derived from the Western Europe–North Atlantic region.
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He, Zhuoqi, Renguang Wu, Weiqiang Wang, Zhiping Wen e Dongxiao Wang. "Contributions of Surface Heat Fluxes and Oceanic Processes to Tropical SST Changes: Seasonal and Regional Dependence". Journal of Climate 30, n. 11 (8 maggio 2017): 4185–205. http://dx.doi.org/10.1175/jcli-d-16-0500.1.
Testo completoAbstract (sommario):
Abstract The present study employs six surface heat flux datasets and three ocean assimilation products to assess the relative contributions of surface heat fluxes and oceanic processes to the sea surface temperature (SST) change in the tropical oceans. Large differences are identified in the major terms of the heat budget equation. The largest discrepancies among different datasets appear in the contribution of vertical advection. The heat budget is nearly balanced in the shortwave-radiation- and horizontal-advection-dominant cases but not balanced in some of the latent-heat-flux- and vertical-advection-dominant cases. The contributions of surface heat fluxes and ocean advections to the SST tendency display remarkable seasonal and regional dependence. The contribution of surface heat fluxes covers a large geographical area. The oceanic processes dominate the SST tendency in the near-equatorial regions with large values but small spatial scales. In the Pacific and Atlantic Oceans, the SST tendency is governed by the dynamic and thermodynamic processes, respectively, while a wide variety of processes contribute to the SST tendency in the Indian Ocean. Several regions have been selected to illustrate the dominant contributions of individual terms to the SST tendency in different seasons. The seasonality and regionality of the interannual air–sea relationship indicate a physical connection with the mean state.
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Armitage, David. "World History as Oceanic History: Beyond Braudel". Historical Review/La Revue Historique 15, n. 1 (20 maggio 2019): 341. http://dx.doi.org/10.12681/hr.20462.
Testo completoAbstract (sommario):
Until recently, most historians shared a prejudice in favour of the history of land, territory and their human inhabitants. Yet two-thirds of the world’s surface is water and much of human history has been conducted on its shores, around its seas and across its oceans. This article proposes reimagining the history of the world through its oceans and seas and examines the multiple genealogies of oceanic history, Mediterranean, Pacific and Atlantic among them. It argues that these models do not exhaust the potential for an oceanic history of the world. It takes the example of the Atlantic and its history to show how models from other oceanic arenas can help us to open up new histories, of regions within larger oceans, of the transnational connections between oceans and of the world beneath the waves.
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George, William P. "Theologically Shoring Up the Law of the Sea". Theological Studies 84, n. 2 (26 maggio 2023): 265–92. http://dx.doi.org/10.1177/00405639231169965.
Testo completoAbstract (sommario):
In Laudato Si’, Pope Francis highlights the oceans as integral to our threatened common home and stresses the need for more effective ocean governance. Theologians can help to meet that need. By turning their attention to the UN Convention on the Law of the Sea (UNCLOS) and its further development, and by practicing “ocean empathy,” they can join ocean scientists, NGOs, international lawyers, and others in caring for the oceans by shoring up the law of the sea.
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Nam, Sunghyun. "Observing the oceans to predict the future". Impact 2019, n. 9 (20 dicembre 2019): 9–11. http://dx.doi.org/10.21820/23987073.2019.9.9.
Testo completoAbstract (sommario):
The ocean covers more than 70 percent of the surface of the planet and some 97 percent of the Earth's water can be found in our oceans. Many of the serious global issues we face, such as warming waters, melting ice and rising sea levels, are directly related to seas and oceans across the world. There is also the increased threat of natural disasters such as typhoons and hurricanes, tsunamis, heatwaves and floods. Many of these issues are directly related to ocean processes and so it follows that in order to combat these issues, it is vital that we find a means of better monitoring, predicting and understanding ocean environments. The Ocean Observation Laboratory (OOL), based at the Seoul National University, Republic of Korea, was founded in 2014 by Professor SungHyun Nam, who leads a laboratory intent on developing our understanding of the oceans to generate scientific findings that will increasingly become a focal point of our lives. The team at the laboratory is currently composed of 15 members, including graduate students, who work together to improve ocean-observing techniques using state-of-the-art technology. The team collaborates closely with industrial and academic partners as well as national and international ocean observation networks to pool knowledge and speed up the process of improving our understanding of the oceans.