Ocean

La peau, ce « premier‑né de nos organes des sens et aussi le plus vaste de nos moyens de communication avec l’extérieur » (Wolff‑Quenot, 2001) est ce qui nous met en contact avec les éléments, dans un dialogue incessant entre notre environnement intérieur et extérieur. Elle a un rôle clé dans nos représentations et perceptions des milieux, puisqu’elle les rend sensibles. La nature peut entrer dans le corps à la manière de l’océan qui en pénètre ses pores (Andrieu, 2019, 40), ses interstices, ses plis et ses creux, y laissant alors son empreinte à travers des traces de gerçures, de décoloration ou encore de brûlures. L’océan agit en tant que perturbateur sur le microbiote cutané qui peut mener à certaines infections et pathologies selon l’ASM. Cette communauté de micro‑organismes vivants, qui est différente sur chaque peau avant la baignade, devient alors identique à tous les individus après qu’ils se sont immergés dans un même lieu océanique. L’eau de mer modifie donc la surface du corps, elle ramollit les plaies et leurs croûtes, rappelant alors peut‑être à la peau, à travers ce mimétisme liquide, que sa composition a quasiment la même teneur en sel que celle de la majorité des océans. Ainsi notre humanité est intimement liée à l’élément marin, comme l’évoque le corps fœtal baigné dans « l’enveloppe de maternage » (Cupa, 2006) pleine du liquide amniotique proche de la composition des eaux marines (Pelizzani, Tovaglieri, 2005, Schirrer, 2015).

Et c’est alors une eau salée soignante, un océan‑médecine dans lequel on s’immerge pour tenter de dissoudre ses maux. L’enveloppement du corps dans la matière aquatique, l’absorption de l’élément par l’organisme, ou bien l’application de dérivés marins sur la peau renvoie à des archétypes de régénérations, d‘effacement du temps si ce n’est d’immortalité. L’immersion dans une mer glacée en vue de raffermir la peau tout comme le système immunitaire saisit le corps dans un réflexe de piloérection, éveillant alors, à travers la peau, le corps trop endormi par le quotidien. Ainsi, l’océan qui abîme la peau peut aussi la soigner, grâce aux diverses vies qu’il contient, tels le plancton, les algues. Une eau vivante qui résonne avec le corps vivant, lui offrant l’espoir d’une certaine harmonie avec le cosmos dont il fait partie.

Les eaux marines sont utilisées depuis des siècles sous différentes aires culturelles, pour le soin tout comme pour les modifications corporelles à l’exemple des îles Chuuk en Micronésie, où le bain de mer avant le lever du soleil aurait de grandes vertus, notamment celles d’apaiser les traitements abrasifs des petites lèvres vulvaires des jeunes filles dans le cadre de l’embellissement des organes génitaux féminins (Moral‑Ledesma 2000, 57). Ces éléments aquatiques sont aussi dotés d’une certaine forme de magie qui permettrait alors une hybridation entre l’humain et le non‑humain grâce à un pouvoir de conversion, où la peau deviendrait « lisse comme celle d’un dauphin » comme le relève Artaud dans son travail sur les pêcheurs du banc d’Arquin en Mauritanie (2018, 269), ou bien se couvrirait d’écailles comme le racontent certains surfeurs (Sayeux, Sirost, Andrieu, 2021). C’est un imaginaire partagé qui se retrouve dans de nombreuses œuvres de fiction, en littérature à l’exemple de la Mer de Michelet (1935) pour n’en citer qu’un, tout comme dans les contes traditionnels ou dans maintes formes d’arts et de cultures. Ainsi, des récits de la femme‑poisson, sirène que l’on retrouve dans les jades sculptées Hongshan du néolithique, à la réinterprétation du mythe de Poséidon dans le film Aquaman de James Wan paru en 2018, l’hybridation de l’humain et de l’animal aquatique due à l’immersion dans les eaux de mer semble traverser les époques et les continents. L’imagination fertile que porte en lui cet élément, comme l’a si bien décrit Bachelard, relève de la vie tout comme la mort, de la naissance tout comme de la fin, comme peuvent le montrer les p’eaux salées.

The skin, this “first-born of our organs of the senses and also the largest of our method of communication with the outside” (Wolff-Quenot,2001) is what puts us in contact with the elements, in an unceasing dialogue between our inside and outside environment. It has a key role in our representations and perceptions of the environment, since it makes them sensitive. Nature can enter the body like the ocean that penetrates its pores (Andrieu, 2019, 40), its gaps, its folds and its hollows, leaving its mark there through traces of chapping, discoloration or even burns. The ocean acts as a disruptor on the skin microbiota which can lead to certain infections and pathologies according to the ASM. This community of living microorganisms, which is different on each skin before swimming, then becomes identical to all individuals after they have immersed themselves in a similar place. Seawater therefore alters the surface of the body, it softens the wounds and their crusts, reminding maybe the skin, through this imitation of the liquid, that its composition has almost the same salt content as that the majority of the oceans. Thus, our humanity is intimately linked to the marine element, as evoked by the fetal body bathed in the “mothering envelope” (Cupa, 2006) full of amniotic fluid close to the composition of marine waters (Pelizzani, Tovaglieri, 2005, Schirrer, 2015).

And then it is a healing salt water, an ocean-medicine in which one immerses ourselves to dissolve our ailments. The body wrapping in the aquatic matter, the absorption of the element by the organism, or the application of marine derivatives on the skin refers to archetypes of regeneration, erasure of time if not immortality. Immersion in an icy sea in order to firm the skin just as the immune system seizes the body in a piloerection reflex, then awakening, through the skin, the body too sleepy by the everyday life. Thus, the ocean that damages the skin can also cure it, thanks to the various lives it contains, such as plankton or algae. A living water that resonates with the living body, offering it the hope of a certain harmony with the cosmos of which it is a part.

Marine waters have been used for centuries under different cultural areas, for care as well as for body modifications such as the Chuuk Islands in Micronesia, where sea bathing before sunrise would have great virtues, including relieving the abrasive treatments of the labia minora of young girls as part of the embellishment of the female genital organs (Ledesma 2000, 57). These aquatic elements are also endowed with a certain form of magic that would then allow a hybridization between human and non-human thanks to a power of conversion, where the skin would become “smooth as that of a dolphin” as Artaud points out in his work on fishermen from the Banc d’Arquin in Mauritania (2018, 269), or would be covered with scales as some surfers can tell (Sayeux, Sirost,Andrieu, 2021). It is a shared imagination that can be found in many works of fiction, in literature such as the Sea of Michelet (1935) to name just one, just as in traditional tales or in many forms of arts and cultures. Thus, from the stories of the woman-fish, a mermaid found in carved Hongshan jades from the Neolithic era, to the reinterpretation of the myth of Poseidon in the movie Aquaman by James Wan released in 2018, the hybridization of humans and aquatic animals due to immersion in seawater seems to cross eras and continents. The fertile imagination that this element carries in him, as Bachelard described so perfectly, is a matter of life as well as death, of birth as well as of the end, as can be shown by the salty skins.

The prediction of rubble-mound breakwater damage under wave action has usually relied on costly and time-consuming physical model tests. In this work, artificial neural networks (ANNs) are applied to estimate the outcome of a physical model throughout an experimental campaign comprising of 127 stability tests. In order to choose the network best suited to the problem data, five different activation function options and 38 network architectures are compared. The good agreement found between the physical model and the neural network shows that an ANN may well serve as a virtual laboratory, reducing the number of physical model tests necessary for a project.

Permeable reactive barrier (PRB) technology is increasingly considered for in situ treatment of contaminated groundwater; however, current design formulas for PRBs are limited and do not properly account for all major physical and attenuation processes driving remediation. This study focused on developing a simple methodology to design PRBs that is easy to implement while improving accuracy and being more conservative than the available design methodologies. An empirical design equation and a simple analytical design equation were obtained to calculate the thickness of a PRB capable of degrading a contaminant from a source contaminant concentration s C to a maximum contaminant level MCL C at a Point of compliance POC . Both equations integrate the fundamental components that drive the natural attenuation process of the aquifer and the reactive capacity of the PRB. The empirical design equation was derived from a dataset of random hypothetical cases that used the solutions of the PRB conceptual model (Solution I). The analytical design equation was derived from particular solutions of the model (Solution II) which the study showed fit the complex solutions of the model well. Using the hypothetical cases, the analytical equation has shown that it gives an estimated thickness of the PRB just 15 % lower or higher than the real thickness of the PRB 95 percent of the time. To calculate the design thickness of a PRB, Natural attenuation capacity of the aquifer can be estimated from the observed contaminant concentration changes along aquifer flowpaths prior to the installation of a PRB. Bench-scale or pilot testing can provide good estimates of the required residence times (Gavaskar et al. 2000),

Incidental catch in fishing gears is a serious, worldwide threat to marine megafauna (particularly sea turtles, sharks and marine mammals). In order to inform the implementationa of effective bycatch management strategies, an important first step is to conduct an assessment of the extent of this threat. In the southwest Indian Ocean (SWIO) (from 0 to 25°S, from eastern Africa to 60°E), there is a paucity of published data describing marine mammal bycatch. This review collates available information from a range of sources relating to marine mammal bycatch for nine SWIO countries: Mozambique, Tanzania (including Zanzibar), Kenya, the Seychelles, the Comoros, Mayotte, Madagascar, Reunion Island and Mauritius. An overview of the bycatch issue within each country is provided by considering the following key points: status of marine mammals, fishing effort, bycatch information and mitigation measures. Quantitative information, especially with respect to number of bycaught animals and impact on local populations, was found to be limited (except for Zanzibar). However, it is clear that several fisheries do incidentally catch marine mammals in the region, those of greatest concern being gillnets catching dugong (Dugong dugon) and coastal dolphins (Tursiops aduncus and Sousa chinensis) in Zanzibar and southwest Madagascar. To date, mitigation measures, particularly efforts to reduce the use of these gears, have not been employed effectively. From the information provided in this review, it is evident that it is critical to initiate the collection of quantitative data for marine mammal bycatch (particularly in gillnets) and its impact on local marine mammal populations and to implement relevant and effective mitigation measures.

Silicon isotopic signatures (delta30Si) of water column silicic acid (Si(OH)4) were measured in the Southern Ocean, along a meridional transect from South Africa (Subtropical Zone) down to 57° S (northern Weddell Gyre). This provides the first reported data of a summer transect across the whole Antarctic Circumpolar Current (ACC). delta30Si variations are large in the upper 1000 m, reflecting the effect of the silica pump superimposed upon meridional water transfer across the ACC: the transport of Antarctic surface waters northward by a net Ekman drift and their convergence and mixing with warmer upper-ocean Si-depleted waters to the north. Using Si isotopic signatures, we determine different mixing interfaces: the Antarctic Surface Water (AASW), the Antarctic Intermediate Water (AAIW), and thermoclines in the low latitude areas. The residual silicic acid concentrations of end-members control the delta30Si alteration of the mixing products and with the exception of AASW, all mixing ...

Computational fluid dynamics (CFD) calculations of pump sumps are troublesome due to the nature of the flow. Pump sump flow is turbulent and unsteady, and pump sump dimensions are large compared to diameter of vortices occurring near the sump walls or in the pump column. Therefore, to capture the general and important phenomena of the flow, the computational grid should be fine enough at certain areas of the sump. Combined with unsteady calculations, this usually results in computationally expensive cases. The decision for a suitable turbulent model plays an important role in adding or reducing the computational costs. The present study first compares some different turbulent models on a fine computational grid to the published experimental model. The intention of the present work is to get an answer whether the Unsteady Reynolds Averaged Navier-Stokes (URANS) model really fails in predictions of vortex modeling, since the usage of Large Eddy Simulation (LES) model for industrial cases would represent huge computational power demands. In the second part of the paper a real case pump sump is analyzed.

In the late 1990s, the application of a well known mathematical transformation revolutionized the music industry. That process, known as Auto-Tune, relies on the ability of the Fourier Transform to identify dominant frequencies within a time-series record of a signal. Mega-stars like Madonna, Cher, Britney Spears, Tim McGraw, Kanye West, and many more heavily use Auto-Tune not only to ensure perfect pitch, but often simply for the unique sounds the function produces. Perhaps unknown to these singers, wave experts were using exactly the same mathematical functions to identify ocean wave characteristics forty years prior to the first mainstream music hit (Cher's "Believe") to use Auto-Tune. This paper presents an overview of the Fourier Transform and its application in both the music industry and the scientific study of water waves.

Résultat d’une enquête socio-anthropologique menée sur le terrain durant trois années, sur les Côte Basque et Landaise (France), ce livre analyse la parole des surfeurs et des surfeuses en répondant à cette question : « Que font réellement les surfeurs quand ils disent qu’ils font du surf ? » . L'auteure "montre comment les pratiquants "bricolent" une identité par jeux de don et de contre-don en relation avec eux-même, les autres et l'environnement." (J.P Augustin, 2008, 108). En analysant l'histoire, dont la stigmatisation qu'a pu subir le surf, les modalités d'apprentissage, le rapport au corps, au genre, à la nature, ce livre montre quels sont les rites, les représentations, et les symboles propres à cette pratique. L'auteure propose de voir dans le surf "une thérapeutique de sociabilités détériorées ",  pouvant, d'une certaine façon, répondre à la crise de sens de nos sociétés contemporaines.



(J.P Augustin, Agora n°50, 4°trimestre, INJEP, 2008, pp. : 106-108)

A new numerical general circulation ocean model for the Mediterranean Sea has been implemented nested within an Atlantic general circulation model within the framework of the Marine Environment and Security for the European Area project (MERSEA, Desaubies, 2006). A 4-year twin experiment was carried out from January 2004 to De-5 cember 2007 with two different models to evaluate the impact on the Mediterranean Sea circulation of open lateral boundary conditions in the Atlantic Ocean. One model considers a closed lateral boundary in a large Atlantic box and the other is nested in the same box in a global ocean circulation model. Impact was observed comparing the two simulations with independent observations: ARGO for temperature and salinity profiles 10 and tide gauges and along-track satellite observations for the sea surface height. The improvement in the nested Atlantic-Mediterranean model with respect to the closed one is particularly evident in the salinity characteristics of the Modified Atlantic Water and in the Mediterranean sea level seasonal variability.

Numerical prediction of an efficiency of a 6-blade Kaplan turbine is presented. At first, the results of steady state analysis performed by different turbulence models for different operating regimes are compared to the measurements. For small and optimal angles of runner blades the efficiency was quite accurately predicted, but for maximal blade angle the discrepancy between calculated and measured values was quite large. By transient analysis, especially when the Scale Adaptive Simulation Shear Stress Transport (SAS SST) model with zonal Large Eddy Simulation (ZLES) in the draft tube was used, the efficiency was significantly improved. The improvement was at all operating points, but it was the largest for maximal discharge. The reason was better flow simulation in the draft tube. Details about turbulent structure in the draft tube obtained by SST, SAS SST and SAS SST with ZLES are illustrated in order to explain the reasons for differences in flow energy losses obtained by different turbulence models.

The prediction of rubble-mound breakwater damage under wave action has usually relied on costly and time-consuming physical model tests. In this work, artificial neural networks (ANNs) are applied to estimate the outcome of a physical model throughout an experimental campaign comprising of 127 stability tests. In order to choose the network best suited to the problem data, five different activation function options and 38 network architectures are compared. The good agreement found between the physical model and the neural network shows that an ANN may well serve as a virtual laboratory, reducing the number of physical model tests necessary for a project.

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The results of an investigation carried out during June 2005 to May 2007 on bloom-forming phytoplankton species composition and abundance in the Parangipettai and Coleroon coastal waters (Southeast coast of India) are reported. Air and surface water temperatures (°C) varied from 25.1 to 30.1 and 24.5 to 28.5, respectively, in the former waters and from 25.5 to 31.2 and 25.0

In the framework of the EU-funded MF-STEP project, autonomous drifting profilers were deployed throughout the Mediterranean Sea to collect temperature and salinity profile data and to measure subsurface currents. The realization of this profiler program in the Mediterranean, referred to as MedArgo, is described and assessed using data collected between June 2004 and December 2006 (including more than 2000 profiles). Recommendations are provided for the permanent future implementation of MedArgo in support of operational oceanography in the Mediterranean Sea.

1. Many marine ecosystems are in critical decline.
2. Iterative assessments of the costs, benefits, and problems associated with conservation initiatives such as marine protected areas (MPAs) can help to improve their effectiveness.
3. The increasingly popular framework of marine spatial planning (MSP) provides opportunities for improving marine management but also needs to avoid similar shortfalls to those identified for MPAs.
4. There is a critical need for realistic presentation of the scope and capacity of MPAs to counteract biodiversity loss, both in isolation and as part of marine spatial planning or other approaches to complementary management.
5. The purpose of this viewpoint is to generate increased momentum to integrate MPAs with other strategies and to recognize the important advances that have been made in MPA planning, implementation and management.

During the Vema-TRANSIT (Bathymetry of the Vema-Fracture Zone and Puerto Rico TRench and Abyssal AtlaNtic BiodiverSITy Study) expedition from December, 2014 to January, 2015, a transect along the Vema Fracture Zone in the equatorial Atlantic was surveyed and sampled at about 10°N. The Vema Fracture Zone is one of the largest fracture zones of the Mid-Atlantic Ridge and it is characterized by a large left-lateral offset. Benthic communities of the transect and the abyssal basins on both sides were investigated to examine whether the Mid-Atlantic Ridge serves as a physical barrier for these organisms, or if there is a potential connection from east to west via the Vema Fracture Zone. Samples comprised 4149 polychaetes, belonging to 42 families. Exemplary, Polynoidae and Spionidae, both typical deep-sea families with high abundances in all investigated regions, were identified up to species level. The present results show significant differences in polychaete faunistic composition between both sides of the Mid-Atlantic Ridge. Moreover, the eastern and western Vema Fracture Zone characterizes divergent habitats, since the two basins differ in sedimentology and environmental variables (e.g. temperature, salinity), hence characterizing divergent habitats. Most species found were restricted to either eastern or western VFZ, but there was a trans-Mid-Atlantic Ridge distribution of certain abundant species observed, indicating that the Mid-Atlantic Ridge might rather act limiting to dispersal between ocean basins than as an absolute barrier. Given the abyssal valley formed by the Vema Fracture Zone and its role in oceanic currents, this seafloor feature may well represent exchange routes between eastern and western faunas.

Abstract Using two dimensional continuous wavelet transforms, a novel method for identification of mesoscale eddies is presented to facilitate extraction of characteristics for area, amplitude, type, and location from maps of sea level anomalies. In comparison with the previously established growing method for eddy identification, it is found that the wavelet method identifies more than twice the number of eddies and is particularly better at resolving small eddies down to the 0.25 degree resolution of the data. Such research into eddy identification and tracking is significant to the assessment of eddies with potential to impact on coastlines of small islands. The method is applied to the identification of eddies on tracks towards islands of the Eastern Caribbean over 23 years. Spatial and temporal variation in rate of occurrence and magnitude is established. For Barbados there is an average of 9 anticyclonic incidents a year with maximum amplitude of typically 0.22 m in the dry seasons and 0.16 m in the wet seasons. Seasonal variation is reversed for the other islands with twice the number of anticyclonic incidents having maximum amplitudes of about 0.20 m annually.

Coastal upwelling along the coast of California has become more variable than during nearly any period in the past 600 years. Black et al. used a 576-year tree ring record to construct a record of wintertime climate along the California coast. Because wintertime climate and coastal upwelling are so closely linked there, they were able to determine that upwelling variability has increased more over the past 60 years than for all but two intervals during that time. The apparent causes of the recent trend appear to be unique, resulting in reduced marine productivity and negative impacts on fish, seabirds, and mammals.

This article analyses the processes of representation and perception of the Pacific Ocean landscape as derived from the narrative of the voyage by Gemelli Carreri (1698) on board of the Manila Galleon. The article also introduces the concept «Sailscape» as the practical and symbolic construction of the oceanic environment and as part of the navigation and geographical imagination. The theoretical analysis of the Pacific «sailscape» has been illustrated by means of Gemelli’s text. In addition to that, the navigator’s scope and the ship’s trip have been regarded as spatial agents in the construction of the landscape.

Este trabajo analiza los procesos de representación y percepción del paisaje del océano Pacífico a partir de la narración del viaje de Gemelli Carreri (1698) a bordo del Galeón de Manila. Presenta el concepto «Sailscape» como construcción práctica y simbólica del entorno oceánico, como parte de la navegación y de la imaginación geográfica. Con el texto de Gemelli se ha ilustrado el análisis teórico del «sailscape» pacífico, atendiendo a la mirada del navegante y al recorrido de la nave como agentes espaciales en la construcción del paisaje.

The Gulf of Kachchh in western India, with its arid climate, large semi-diurnal tidal amplitudes, negative water balance and near-pristine water quality, is being extensively developed as oil importing bases for economic reasons in connection with its proximity to the oil exporting countries of the Middle East. Besides, new coral rubbings were sighted in Jakhau, north-western Gulf of Kachchh. Dredging in Mandvi of the north Gulf covering 3.5 km 2 revealed a similar assortment of live corals with their associated flora and fauna. These pioneering observations demonstrate that there exist live corals of young polyps-colony of Favia sp. belonging to the family Faviidae in the north-western Gulf of Kachchh. The environmental parameters there were carefully recorded as: surface water temperature (℃) varying from 29 to 31.8, salinity (ppt), pH, dissolved oxygen (mgL -1 ) and total suspended solids (mgL -1 ) in the ranges of 37-43.5, 7.7-8.45, 5.4 -6.8 and 11-31, respectively.

Using a recently developed spectral nonlinear gravity wave (GW) parameterization implemented into a 3-D coupled general circulation model, the effects of a broad spectrum of small-scale internal GWs of lower atmospheric origin on the equinoctial thermosphere are studied for the first time. GWs propagate to F region altitudes in both hemispheres, producing appreciable drag on the mean zonal wind. Some modifications of the two-cell equinoctial mean circulation by GWs are simulated, too. The mean zonal GW drag is comparable to the ion drag up to $ 260 km in the middle-and high-latitudes. While the mean dynamical effect of GWs is the deceleration of the mean flow, the instantaneous GW body force can have both signs. In the Southern Hemisphere high-latitude, GWs are found to produce large torque of more than 1000 m s À 1 day À 1 the mechanism of which is investigated in detail. GW anisotropy plays a crucial role in offsetting and modulating wave filtering, introducing increased favourable conditions for westerly harmonics in the high-latitudes. This leads to a very large localized eastward GW drag reaching a maximum in the upper thermosphere as a consequence of enhanced molecular viscosity, thermal conduction, and ion drag. Finally, the high-latitude distribution of the GW body force is presented in the upper thermosphere along with the comparison with ion drag. It demonstrates significant interhemispheric differences and large longitudinal variations in GW momentum deposition.

A recent review of all ivory from excavations in Chalcolithic and Beaker period Iberia shows a marked coastal distribution -which strongly suggests that the material is being brought in by sea. Using microscopy and spectroscopy, the authors were able to distinguish ivories from extinct Pleistocene elephants, Asian elephants and, mostly, from African elephants of the savannah type. This all speaks of a lively ocean trade in the first half of the third millennium BC, between the Iberian Peninsula and the north-west of Africa and perhaps deeper still into the continent.

Recent case studies on the precursor signatures of equatorial spread-F (ESF) have shown a one-to-one correspondence between the large-scale wave structures (LSWS) and ESF development at equatorial latitude. In this study, the LSWS and the onset and development of the ESF are investigated over Sanya (18°N, 109°E), a station located at 13° north of the magnetic equator, during both geomagnetic quiet and disturbed conditions in September–October 2011. High-time-resolution ionograms from Digisonde Portable Sounder (DPS-4D) provided the satellite trace measurements that were used to indicate the occurrence of the LSWS. The development of local ESF activity was identified using GPS scintillation and VHF coherent radar echo measurements from the same site, together with the range type spread-F (RSF) in ionograms. Additionally, the Sanya VHF radar five-beam scanning measurements in east–west direction were used to characterize the longitudinal difference in establishing the initial conditions for ESF development. Correlative studies between the LSWS and ESF activities during the observational period offer consolidated evidence that the LSWS is a necessary precursor for the ESF development. It is shown that the LSWS and ESF have nearly a one-to-one relationship when the F layer undergoes an abrupt post-sunset rise (PSSR), revealing that the magnitude of the pre-reversal enhancement in zonal electric field (PRE) that elevates the F layer to a high enough altitude is an important parameter controlling the generation of post-sunset ESF. However, in the absence of the PSSR, the ESF and GPS scintillation did not always occur following the appearance of LSWS. Sometimes the LSWS events preceded the generation of bottom type spread-F (BSF) that did not develop vertically into ESF and radar plumes. This result may indicate that under inexpressive, weak, or even moderate PRE conditions, the appearance of the LSWS alone may not be sufficient to produce the post-sunset F region irregularities responsible for ionospheric scintillations. More factors, other than the LSWS, could play crucial roles favoring the growth of ESF instabilities responsible for ionospheric scintillations.

We consider the effects of chordwise flexibility on the aerodynamic performance of flapping wings using numerical simulation. The two-dimensional Navier–Stokes equations are solved using a Fourier pseudo-spectral method with no-slip boundary conditions imposed by the volume penalization method. The flexible wing is modelled with a non-linear beam equation. Our numerical simulations of heaving plates show that the maximum thrust is achieved at a stroke frequency lower than resonant, which is in agreement with experiments. The oscillatory part of the force only increases in amplitude when the frequency increases. We also consider aerodynamic interactions between two heaving foils.

This article is focused on the choice of a suitable turbulence model for simulations of an industrial pump's intake, from the perspective of accuracy and, partially, also the CPU time. Twelve steady-state and transient simulations were made on a fine computational mesh, using turbulence models such as: the shear stress transport (SST), the scale-adaptive simulation (SAS), the Reynolds stress model, the explicit algebraic Reynolds-stress model, the detached eddy simulation and the large eddy simulation (LES). The curvature-correction (CC) option was assessed for the SST and SAS turbulence models. The results were compared with the LES and with published experimental results. Although all the models could predict the main floor vortex, there were still some substantial differences. It can be able to conclude that it is better to use either the SST-CC turbulence model, due to its low-computational resources and far better results than the SST model, or the SAS-CC turbulence model, since its predictions are quite similar to the LES results. In the final step, good agreement with experimental results was shown for a longer simulation with the SAS-CC turbulence model.

We present a newly developed unstructured high order h/p Discontinuous Galerkin Finite Element solver for the computation of tidal turbine hydrodynamics. The solver allows for accurate flow solutions of the two dimensional incompressible Navier-Stokes equations on hybrid meshes (triangular-quadrilateral) with rotating geometries using sliding mesh interfaces. High accuracy is obtained by enabling arbitrary polynomial orders within each mesh element allowing mesh size refinement (h-refinement) and/or polynomial enrichment (p-refinement).

The solver is validated for static NACA0012 and NACA0015airfoil flows for a range of Reynolds numbers including laminar and turbulent regimes. Results for a typical cross-flow tidal turbine are also included for laminar flows and the resulting flowphysics explored. Wake-blade interference effects are analysed for single and three bladed turbines. Results for a three bladed turbine under ducted conditions (tidal fence concept) are also reported.We show that the solver provides accurate results and is thus a valuable tool to accurately predict flows through cross-flow tidal turbine devices and to explore their hydrodynamics.

In this research paper, a Bajaj rickshaw vehicle was tested under variable loads and five different oil-fuel mixture ratios ranging between 2% and 12.5%. Three readings of each experiment were taken and average values were extracted. It was found that oil-fuel mixture ratios which lie between 2% and 5% are the most suitable ratios that could be used by rickshaw drivers and technician mechanics. These ratios are recommended to be used because they give the vehicle's engine higher acceleration, longer operation period life, diverge the overhaul maintenance period intervals, and that they cause less impact to the surrounding environment. Abstract-In this research paper, a Bajaj rickshaw vehicle was tested under variable loads and five different oil-fuel mixture ratios ranging between 2% and 12.5%. Three readings of each experiment were taken and average values were extracted. It was found that oil-fuel mixture ratios which lie between 2% and 5% are the most suitable ratios that could be used by rickshaw drivers and technician mechanics. These ratios are recommended to be used because they give the vehicle's engine higher acceleration, longer operation period life, diverge the overhaul maintenance period intervals, and that they cause less impact to the surrounding environment.

A coastal observing system for Northern and Arctic Seas (COSYNA) aims at construction of a long-term observatory for the German part of the North Sea, elements of which will be deployed as prototype modules in Arctic coastal waters. At present a coastal prediction system deployed in the area of the German Bight integrates near real-time 5 measurements with numerical models in a pre-operational way and provides continuously state estimates and forecasts of coastal ocean state. The measurement suite contributing to the pre-operational set up includes in situ time series from stationary stations, a High-Frequency (HF) radar system measuring surface currents, a FerryBox system and remote sensing data from satellites. The forecasting suite includes nested 10 OSD the observing system in Liverpool Bay .

Stratospheric preconditions for the annual Antarctic ozone hole are analyzed using the amplitude of quasistationary planetary waves in temperature as a predictor of total ozone column behaviour. It is found that the quasistationary wave amplitude in August is highly correlated with September-November total ozone over Antarctica with correlation coefficient (r) as high as 0.83 indicating that quasi-stationary wave effects in late winter have a persisting influence on the evolution of the ozone hole during the following three months. Correlation maxima are found in both the lower and middle stratosphere. These likely result from the influence of wave activity on ozone depletion due to chemical processes, and ozone accumulation due to largescale ozone transport, respectively. Both correlation maxima indicate that spring total ozone tends to increase in the case of amplified activity of quasi-stationary waves in late winter. Since the stationary wave number one dominates the planetary waves that propagate into the Antarctic stratosphere in late austral winter, it is largely responsible for the stationary zonal asymmetry of the ozone hole relative to the South Pole. Processes associated with zonally asymmetric ozone and temperature which possibly contribute to differences in the persistence and location of the correlation maxima are discussed.

Both ?14C, ?13C for the particulate organic matter (POM) and 3-Dimensional Excitation and Emission Matrix spectroscopy (3D-EEM) for the dissolved organic matter (DOM) were used to study transport behavior from land to ocean in Hokkaido, Japan. The ?14C values of the Tokachi POC (particulate organic carbon) show similar variations to Ishikari. However, the variation range of the Tokachi of ?14C is smaller than that of the Ishikari POC. ?13C values for the Ishikari showed larger variation range than those of the Tokachi. The POC during spring snow-melting for the Ishikari and in autumn during heavy rain fall for the Tokachi were distinctive in the correlations of POC, ?14C, and ?13C.There were two different pathways in the correlations of POC content, ?14C, and water discharge for both river systems. The significant pathway during snow-melting found in the Ishikari and at autumn during heavy rain fall for the Tokachi. The Tokachi and the Ishikari River showed similar variations patter...

A coastal observing system for Northern and Arctic Seas (COSYNA) aims at construction of a long-term observatory for the German part of the North Sea, elements of which will be deployed as prototype modules in Arctic coastal waters. At present a coastal prediction system deployed in the area of the German Bight integrates near real-time measurements with numerical models in a pre-operational way and provides continuously state estimates and forecasts of coastal ocean state. The measurement suite contributing to the pre-operational set up includes in situ time series from stationary stations, a High-Frequency (HF) radar system measuring surface currents, a FerryBox system and remote sensing data from satellites. The forecasting suite includes nested 3-D hydrodynamic models running in a data-assimilation mode, which are forced with up-to-date meteorological forecast data. This paper reviews the present status of the system and its recent upgrades focusing on developments in the field of coastal data assimilation. Model supported data analysis and state estimates are illustrated using HF radar and FerryBox observations as examples. A new method combining radial OSD

In a sensitivity experiment, an eddy-permitting ocean general circulation model is forced with freshwater fluxes from the Greenland Ice Sheet, averaged for the period 1991-2000. The fluxes are obtained with a mass balance model for the ice sheet, forced with the ERA-40 reanalysis dataset. The freshwater flux is distributed around 5 Greenland as an additional term in prescribed runoff, representing seasonal melting of the ice sheet and a fixed year-round iceberg calving flux, for 8.5 model years. The impacts on regional hydrography and circulation are investigated by comparing the sensitivity experiment to a control experiment, without Greenland fluxes. By the end of the sensitivity experiment, the majority of additional fresh water has accumulated 10 in Baffin Bay, and only a small fraction has reached the interior of the Labrador Sea, where winter mixed layer depth is sensitive to small changes in salinity. As a consequence, the impact on large-scale circulation is very slight. An indirect impact of strong freshening off the west coast of Greenland is a small anti-cyclonic circulation around Greenland which opposes the wind-driven cyclonic circulation and reduces net south-15 ward flow through the Canadian Archipelago by ∼10%. Implications for the post-2000 acceleration of Greenland mass loss are discussed. 25 (FWF), which can be prescribed as forcing in an ocean circulation model. Such an 2912 OSD

Numerical prediction of an efficiency of a 6-blade Kaplan turbine is presented. At first, the results of steady state analysis performed by different turbulence models for different operating regimes are compared to the measurements. For small and optimal angles of runner blades the efficiency was quite accurately predicted, but for maximal blade angle the discrepancy between calculated and measured values was quite large. By transient analysis, especially when the Scale Adaptive Simulation Shear Stress Transport (SAS SST) model with zonal Large Eddy Simulation (ZLES) in the draft tube was used, the efficiency was significantly improved. The improvement was at all operating points, but it was the largest for maximal discharge. The reason was better flow simulation in the draft tube. Details about turbulent structure in the draft tube obtained by SST, SAS SST and SAS SST with ZLES are illustrated in order to explain the reasons for differences in flow energy losses obtained by different turbulence models.