Top PDF <i>Preface</i> Large amplitude internal waves in the coastal ocean

<i>Preface</i> Large amplitude internal waves in the coastal ocean

<i>Preface</i> Large amplitude internal waves in the coastal ocean

Most observations of internal solitary waves are for mode one, which has the fastest phase speed. However, recently there have been a few reports of mode two waves. Although mode two internal solitary waves cannot normally exist as steady travelling waves due to a resonance with mode one short waves, they can be generated as transients by interaction with topography. Yang et al. (2010) report observations of mode two waves on the continental slope of the South China Sea, and apparently for the first time, found two distinct types. The usual mode two wave typically has a convex form with a bulge in the pycnocline, and this kind is that usually found, However, the observations reported here show a few cases of a mode two wave with a convex form, with a localized thinning (“anti-bulge”) of the pycnocline. The theoretical explanation, based on the KdV equation, is that for a three-layer fluid structure, a convex mode two wave is found when the middle layer is thin, and a concave mode two wave is found when the middle layer is thick. This latter case is rather unusual on the coastal ocean.
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Propagation regimes of interfacial solitary waves in a three-layer fluid

Propagation regimes of interfacial solitary waves in a three-layer fluid

There are many important topics related to internal waves (IWs) in the ocean. Large IWs are highly significant for sed- iment resuspension and transport (Bogucki and Redekopp, 1999; Stastna and Lamb, 2008; Reeder et al., 2011) and for the biology on the continental shelf (Sandstrom and Elliott, 1984). The currents forced by large or breaking IWs cause powerful forces on marine platforms and submersibles. The associated strong distortion of the density field has a severe impact on acoustic signaling (Apel et al., 2007; Chin-Bing et al., 2009; Warn-Varnas et al., 2009; Sridevi et al., 2011). Their capacity to break and impact the local microstructure has major consequences for the understanding of interior ocean mixing (Muller and Briscoe, 2000). Internal waves are believed to be responsible for substantial damage (Osborne, 2010). High water velocities in intense IWs can create enor- mous local loads and bending moments and represent a po- tential danger to off-shore structures, such as oil platforms, drill rigs, etc. The danger from IWs is considered so critical that, similar to the systems of tsunami warning, the poten- tial for automated detection systems for large-amplitude IWs (internal soliton early warning systems) is being discussed now. Such systems were even tested to support drilling cam- paigns and guarantee the safety of drilling platforms (Stober and Moum, 2011).
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A note on radar altimeter signatures of Internal Solitary Waves in the ocean

A note on radar altimeter signatures of Internal Solitary Waves in the ocean

On March 20, 2015, Jason-2 overpassed the northern Andaman Sea (Pass 090; Cycle 247) at 18:40 UTC, where large amplitude internal solitary waves were observed propagating towards the Andaman Islands. A MODIS Terra image acquired at 04:25 UTC over the same region reveals several large ISW trains propagating to the west-southwest, whose wave fronts extend for at least 100 km approximately along the direction of the altimeter track (see red line in Fig. 3a). In this case the time difference between the overpasses of the two satellites exceeds a semi-diurnal tidal cycle (12.42 hours) in approximately two hours. The tides in the Andaman Sea hold a strong semi-diurnal component, being capable to generate large amplitude ISWs in successive tidal cycles at approximately the same locations every 12h25min. This means that the ISW structure would repeat itself (similar wave trains) every 12h25min, holding the same structure as long as the internal stratification does not change too much. Consequently, images like those in Fig. 3a should be very similar every tidal cycle, and positions of ISW trains should be almost the same. The time difference between the two satellite observations (altimeter and MODIS) is 14h20min, which means one tidal cycle plus 2 hours approximately. Hence, we choose not to correct the wave trains in Fig. 3a to their expected positions at the time of the altimeter overpass. Expected differences in ISW train positions should not exceed 10 km between the altimeter observation and their effective location at that time.
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Differential impact of monsoon and large amplitude internal waves on coral reef development in the Andaman Sea.

Differential impact of monsoon and large amplitude internal waves on coral reef development in the Andaman Sea.

hydrodynamic processes for the linear extension rate and skeletal density in Porites lutea where linear extension rates were found to be inversely related to local hydrodynamics. A relationship between coral community structure and grain size was also observed for Hawaiian reefs [4]. Grain size distribution is a function of wave action, currents and swell, but also determined by i.e. bathymetry [69] affecting sediment mobilization and deposition [55]. Al- though it has been shown that during the dry season LAIW- induced strong currents may account for resuspension and upslope transport of sediments [33] much of the resuspension is due to surface wave resuspension in shallow water with subsequent down slope transport of sediments [55,70]. In general, the grain size properties of the study sites showed that W reefs were subjected to higher current and wave action during both seasons with slightly increased values during the peak SW-monsoon season (Fig. 4C). This suggests that during the NE monsoon LAIW-induced currents lead to an upslope transport and accumulation of finer sediment and to a transport of fine sediments out of the study area during SW monsoon.
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Rolls of the internal gravity waves in the Earth's  atmosphere

Rolls of the internal gravity waves in the Earth's atmosphere

from 1 to 2 and from 3 to 10 percent, respectively (Sherman and Che, 2006; Zhao, 2003). The amplitude of IGWs propa- gating upward throughout the various regions of the Earth’s atmosphere and ionosphere grow with height and become unstable due to parametric instability as a result of resonant wave–wave interaction. Such parametric generation of large- scale zonal structures by high-frequency finite-amplitude IGWs has been investigated recently by Horton et al. (2008) and Onishchenko and Pokhotelov (2012). The existence of the nonlinear IGWs in the form of two-dimensional small- scale vortices (i.e., roll-type structures) has been reported by Kaladze and Tsamalashvili (1997) and Stenflo and Shukla (2009). Recently, Onishchenko et al. (2013) have shown that the finite temperature gradient can substantially modify the condition for the existence of vortex-type structures obtained in previous works.
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J. Coloproctol. (Rio J.)  vol.34 número1

J. Coloproctol. (Rio J.) vol.34 número1

In this phase the surgeon proceeds with the fulguration of the inner side of the i stulous tract. Using the monopole electrode, proceeds with destruction of all the tract under direct vision with cauterization of the bed. The procedure starts near the internal orii ce, retreating little by little, until achieving the external orii ce, concluding the cauterization. Following this, the necrotic material is removed by brushing and l ushing with the washing solution. Finally, the inter- nal orii ce repair is pulled and, with the use of a stapler, the internal orii ce closure is achieved; or a cutaneous-mucosal l ap or orii ce synthesis is performed.
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Auditory brainstem response in neonates: influence of gender and weight/gestational age ratio

Auditory brainstem response in neonates: influence of gender and weight/gestational age ratio

presented by a pair of insert earphones ER-3A, eliciting responses. The impedance of the electrodes remained lower than 3kΩ. The acoustic stimulus used was the rarefaction polarity click, monaurally presented at 80dBnNA for as- sessing auditory pathway integrity, in presentation speed of 27.7 clicks by second, duration of 0.1ms, high pass ilters of 100Hz and low pass of 1.500Hz, totaling 2,048 stimuli. We used a 12-ms recording window. The ABR was captured twice in each ear, in order to obtain wave reproducibility and ensure the presence of response. For the analysis of the ABR responses, absolute latencies of waves I, III, V and the interpeak intervals I-III, III-V, I-V at 80dBnNA were measured. The results of each assessment were recorded and delivered to the parent or legal guardian.
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Cluster observations and theoretical identification of broadband waves in the auroral region

Cluster observations and theoretical identification of broadband waves in the auroral region

We reconstruct the WDF at 50 Hz, using the one-second of data presented in Fig. 10. The observational input to the reconstruction program is made up of the spectral densities at the frequency of interest. Computing the spectral densi- ties we use a record length of 128 points and average over 6 time records. All observed wave components are used, but to avoid possible cross-correlation problems due to, for instance, phase shifts in the electronics, we do not include cross spectra between magnetic and electric wave field com- ponents. WHAMP produces the theoretical input to the re- construction. All wave vectors satisfying the dispersion rela- tion ω=ω(k), that is, a constant frequency curve, together with the corresponding polarization vectors, are provided. It is worth pointing out that in reconstructing the WDF, we make no assumption concerning the third component of the electric field.
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Coastal change and hypoxia in the northern Gulf of Mexico: Part I

Coastal change and hypoxia in the northern Gulf of Mexico: Part I

Enhancing physical erosion potential and concomitant increase of inland water volume is accompanied by increasing amount and efficiency of water and material transmission from the [r]

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Auditory Brainstem Response: reference-values for age

Auditory Brainstem Response: reference-values for age

Each service should set its own normal values , since the absolute latencies of the waves depend on factors such as, for example, the stimulus parameter, the equipment used and the population characteristics such as age and gender. With the implementation of newborn hearing screening (NHS), children at increasingly younger ages are sent for audiological diagnosis. This way, it becomes important to deine normal parameters, using more objective and accurate assessments to establish the diagnosis of peripheral and central hearing disorders as early as possible. Because of the importance of evaluation methods in the diagnosis of hearing disor- ders in children and the increased demand for early identi- ication of hearing disorders in newborns and infants a few months old, it is essential to obtain normative data. These data can reveal patterns of response in this population and help to differentiate them from real alterations, assisting in the interpretation of results and increasing the accuracy of audiological diagnosis (6) .
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I I I I I I I

I I I I I I I

olhos de pacientes com 75 anos apre­ sentam essas membranas'. Embora essa prevalência seja relati vamente alta ape­ nas uma minoria desses olhos apresen­ ta baixa de acuidade visual significa­ tiva; com cerca de 68%8 apresentando acuidade visual melhor que 20/5 0 . MER clinicamente significativas e afe­ tando a mácula, ocorrem em 4 a 8% dos olhos previamente submetidos a cirur­ gia reaplicadora de retina que obtive­ ram sucesso anatômic02. Essas mem­ branas, ao contrário das idiopáticas, usualmente reduzem a acuidade visual significativamente, e cerca de 56% des­ ses olhos apresentam acuidade visual menor que 20/200 9. Ocasionalmente uma membrana epirretiniana pode se separar espontaneamente da retina e resultar em melhora da acuidade vi­ suapo. Acredita-se que esse e vento ocorra em menos de I % dos casos" . Não há tratamento clínico para essas membranas. O tratamento, portanto, quando indicado, é cirúrgico. A cirur­ gia entretanto deve ser considerada apenas para membranas epirretinianas que causem significativa baixa de acui­ dade visual. Temos indicado a cirurgia quando a membrana epirretiniana reduz a acuidade visual a 20/80 ou pior. Esse critério baseia-se no fato de que a recu­ peração é usualmente parcial, raramen­ te possibilitando o retomo da acuidade visual a 20/20, e também pelos riscos de complicações inerentes a esse proce­ dimento, como mostrado nos resulta­ dos. Alguns experientes autores, entre­ tanto, realizam a cirurgia com acuida­ de visual de 20/50 ou pior'2.
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Dynamics of Coastal Systems Using GIS Analysis and Geomaterials Evaluation for Groins

Dynamics of Coastal Systems Using GIS Analysis and Geomaterials Evaluation for Groins

Several statistical methods are available to estimate annual erosion rates and to forecast shoreline positions, such as end point (EP), linear regression, time-series analysis, and geostatistics. The EP rate (EPR) was used in this work and was calculated by dividing the distance of shoreline movement by the time elapsed between the earliest and latest measure- ments (i.e., the oldest and the most recent shoreline). The major advantage of the EPR is its ease of computation and minimal requirement for shoreline data (two shorelines). The major disadvantage is that in cases in which more than two shorelines are available, the information about shoreline behavior provided by additional shorelines is neglected. Thus, changes in sign or magnitude of the shoreline movement trend or cyclicity of behavior may be missed. For the Espinho coastal area we determined eight zones representing different beach areas, and we also vectorized the lines to evaluate displacement of the head zone of the groins. The DSAS extension was then applied to assess the evolution of the shoreline according to the parameters indicated in Figure 4. The methodology applied in the present study combines several field techniques and various types of inputs/tools (Figure 4), establishing an interdisci- plinary connection of geoengineering concepts and an analysis of coastal dynamics for the planning of maritime structures.
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The lifecycle of axisymmetric internal solitary waves

The lifecycle of axisymmetric internal solitary waves

value of ν = 0.01 cm 2 /s was used. Between these regions the viscosity varied linearly with r. The dynamics of the flow were unaffected using this viscosity because the Reynolds numbers were on the order of 10 3 which suggests that viscosity did not govern the dominant motion. To confirm this, a high resolution simulation with a uniform viscosity of 0.01 cm 2 /s was performed, this taking many days rather than many hours to run. The propagation and speed of the intrusion near the lock remained unchanged. The diffusivity of salt water, κ, was set to be everywhere equal to ν, even though its physical value is 10 −5 cm 2 /s. The purpose of doing this is again for numerical stability. Nonetheless the value of κ was sufficiently small that molecular diffusion had a negligible influence on the flow.
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Calcification in the planktonic foraminifera <i>Globigerina bulloides</i> linked to phosphate concentrations in surface waters of the North Atlantic Ocean

Calcification in the planktonic foraminifera <i>Globigerina bulloides</i> linked to phosphate concentrations in surface waters of the North Atlantic Ocean

de Villiers (2004) suggested that SNWs are linked more closely to optimum growth con- ditions than [CO 2− 3 ]. de Villiers used relative abundance as a proxy for optimum growth conditions assuming that favourable environmental variables will result in greater abun- dances of foraminifera. Beer et al. (2010a) were unable to lend support to this hypoth- esis. Results from the current study also found no statistically significant relationship

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Effects of ocean acidification on the larval growth of olive flounder (<i>Paralichthys olivaceus</i>)

Effects of ocean acidification on the larval growth of olive flounder (<i>Paralichthys olivaceus</i>)

Orr, J. C., Fabry, V. J., Olivier, A., Bopp, L., Doney, S. C., Feely, R. A., Gnanadesikan, A., Gru- ber, N., Ishida, A., Joos, F., Key, R. M., Lindsay, K., Maier-Reimer, E., Matear, R., Monfray, P., Mouchet, A., Najjar, R. G., Plattner, G. K., Rodgers, K. B., Sabine, C. L., Sarmiento, J. L., Schliter, R., Slater, R. D., Totterdell, I. J., Weirig, M. F., Yamanaka, Y., and Yool, A.: Anthro- pogenic ocean acidification over the twenty-first century and its impact on calcifying organ-

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High-resolution ocean pH dynamics in four subtropical Atlantic benthic habitats

High-resolution ocean pH dynamics in four subtropical Atlantic benthic habitats

measurements could therefore not be made simultaneously at all four sites due to lo- gistic restrictions. The study was also disrupted because the pH sensor located in the encrusting coralline algae site was subject to vandalism during the second sampling period – no data could be gathered for this particular time in this phytocenosis. The location and study periods for each different site are summarized in Table 1.

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Negligible effects of ocean acidification on <i>Eurytemora affinis</i> (Copepoda) offspring  production

Negligible effects of ocean acidification on <i>Eurytemora affinis</i> (Copepoda) offspring production

Acknowledgements. We would like to thank the staff of Tvärminne Zoological Station for providing working facilities during the experiment. We also thank the entire KOSMOS team for the joint sampling effort. We thank Michael Sswat for his attribution to the C : N analyses. We also thank the crew of R/V Alkor (AL394, A397) for transportation, deployment and recovery of the mesocosms, as well as the diving team. Special thanks go to Andrea Ludwig for organizing logistics and to Bettina Grönlund for assistance with zooplankton sampling and in the lab. The study was funded by Walter and Andrée de Nottbeck Foundation, Victoriastiftelsen, Academy of Finland (project nr. 276947), the Onni Talas founda- tion, Lennart Bach received funding from the BIOACID project (W. P. 1.3) and A. J. Paul from Excellence Cluster ‘The Future Ocean’ (Project CP1141). The collaborative project was funded by German Ministry of Education and Research (BMBF) BIOACID II (FKZ 03F06550), SOPRAN II (FKZ 03F0611) and MESOAQUA (228224).
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Effect of predation on <i>Anopheles</i> larvae by five sympatric insect families in coastal Kenya

Effect of predation on <i>Anopheles</i> larvae by five sympatric insect families in coastal Kenya

Resource competition is a common phenomenon amongst insects. Notonectids combined with hydrometrids yielded a higher larvae and pupae consumption rates sug- gesting that there is an interspecific competition on the prey population. The competition effects of notonectids and hydrometrids contributed to the increased consumption of the larvae and pupae which were their shared natural prey. The results of this study further suggest that there was interspecific competition on the prey populations. The interspecific competition effects of notonectids and hydrometrids contributed to increased consumption of the anopheline larvae and pupae. In natural settings, habitats which have the two predators present may impact nega- tively the Anopheles larval population, lowering the habitat’s productivity and contribution to adult mosquitoes. Dytiscids, like the Coleoptera as a whole, are a highly divergent family of insects, with sizes ranging several orders of magnitude. While the small species of dytiscid used in these experiments was a prey organism for notonectids, it is likely that the many larger species would instead predate upon the notonectids. The impacts of other predators such as dragonfly nymphs, adult and larvae of dytiscid and hydrophilid beetles are important predators in some pool habitats 4, 5, 24 .
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Psychol. Neurosci.  vol.1 número2

Psychol. Neurosci. vol.1 número2

The iron-deicient diet, in addition to reducing the body weight of group A animals, also caused lower Hb and %Ht compared to W rats of the same age (18, 22 and 32 days), demonstrating that this diet promoted a deicient nutritional condition in anemic rats, as also reported in the study by Cunha et al. (2008). Thus, it permitted the investigation of the effects of anemia on the BAEP of the rats. Although the body weight of all animals increased until the end of the experiment, only W animals showed an increase in Hb and Ht at 32 days compared to rats of 18 and 22 days of age. Anemic animals, although they gained body weight, presented lower quantities of Hb and Ht at 32 days than at 18 and 22 days of age. These results reveal that the imposition of the deicient diet up to 32 days continued to reduce the iron stores in the organism along the period evaluated, reducing Ht and Hb. However, the other components of the diet were adequate, a fact that may have provided the body weight gain, although the animals require iron for cell metabolism and growth and for the adequate development of body tissues (Schmidt et al., 2007).
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Seagrass beds as ocean acidification refuges for mussels? High resolution measurements of <i>p</i>CO<sub>2</sub> and O<sub>2</sub> in a <i>Zostera marina</i> and <i>Mytilus edulis</i> mosaic habitat

Seagrass beds as ocean acidification refuges for mussels? High resolution measurements of <i>p</i>CO<sub>2</sub> and O<sub>2</sub> in a <i>Zostera marina</i> and <i>Mytilus edulis</i> mosaic habitat

ate system at the site was characterized by a strongly varying baseline featuring very steep pCO 2 gradients over the course of the day with slopes of up to ∼ 100 µatm per 17 min (i.e. 1020 s). Therefore the pCO 2 signal recovery from zero to ambient during the flush intervals was always superimposed with a changing background partial pres- sure. These adverse conditions hamper and bias the response time determination by

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