Oceanologica Acta最新文献

{"title":"Three-dimensional numerical model study of the residual current in the South China Sea","authors":"Shuqun Cai,&nbsp;Qizhou Huang,&nbsp;Xiaomin Long","doi":"10.1016/S0399-1784(03)00053-7","DOIUrl":"10.1016/S0399-1784(03)00053-7","url":null,"abstract":"<div><p>A three-dimensional baroclinic shelf sea model is employed to simulate the tidal and non-tidal residual current in the South China Sea. The four most significant constituents, M₂, S₂, K₁ and O₁<span>, are included in the experiments with tidal effect. At most stations, the computed harmonic constants agree well with the observed ones. The circulations of the South China Sea in summer (August) and winter (December) are mainly discussed. It is shown that the barotropic tidal residual current is too weak to affect the South China Sea circulation<span>, whilst the contribution of the baroclinic tidal residual current to the South China Sea circulation would be important in the continental shelf sea areas, especially in the Gulf of Thailand and Gulf of Tonkin. In the deep-sea areas, the upper barotropic or baroclinic tidal residual current is relatively very weak, however, the speed order of the deep baroclinic tidal residual current can be the same as that of the mean current without tidal effect. Moreover, the baroclinic tidal residual current seems to be related to the different seasonal stratification of ocean.</span></span></p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00053-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79812284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The 1867 Virgin Island tsunami: observations and modeling","authors":"Narcisse Zahibo ,&nbsp;Efim Pelinovsky ,&nbsp;Ahmet Yalciner ,&nbsp;Andrey Kurkin ,&nbsp;Andrey Koselkov ,&nbsp;Andrey Zaitsev","doi":"10.1016/S0399-1784(03)00059-8","DOIUrl":"10.1016/S0399-1784(03)00059-8","url":null,"abstract":"<div><p>The 1867 Virgin Island tsunami was of a great effect for the Caribbean Islands. A maximal tsunami height of 10 m was recorded for two coastal locations (Deshayes and St. Rose) in Guadeloupe. The historical data of this event for the Caribbean Sea are discussed. The modeling of the 1867 tsunami is performed in the framework of the nonlinear shallow-water theory. The four different orientations of the tsunami source in the Anegada Passage are examined. The directivity<span> of the tsunami wave in the Caribbean is investigated. The time histories of water surface fluctuations are calculated for several coastal locations on the coasts of the Caribbean Sea. Results of the numerical simulations are in reasonable agreement with data of observations.</span></p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00059-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79946923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic micropollutants (PAHs, PCBs, pesticides) in seaweeds of the lagoon of Venice","authors":"Bruno Pavoni,&nbsp;Michele Caliceti,&nbsp;Laura Sperni,&nbsp;Adriano Sfriso","doi":"10.1016/S0399-1784(03)00052-5","DOIUrl":"10.1016/S0399-1784(03)00052-5","url":null,"abstract":"<div><p><span>Samples of seven genera of seaweeds (</span><em>Ulva</em>, <span><em>Gracilaria</em></span>, <span><em>Porphyra</em></span>, <span><em>Grateloupia</em></span>, <span><em>Undaria</em></span>, <span><em>Fucus</em></span> and <span><em>Cystoseira</em></span><span>), which can be used as environmental biomonitors and in several applications like human alimentation, animal feeding and cosmetics, were collected in four sampling sites in the Lagoon of Venice in spring and autumn 1999 with the aim of determining the contamination due to organic micropollutants (polychlorinated biphenyls, PCBs; chlorinated pesticides; polycyclic aromatic hydrocarbons, PAHs). On an average, most of the considered species were contaminated especially by PAHs (up to 56 ng g</span>^–1 dry wt. (dw)) whereas concentrations of PCBs and pesticides in macroalgal tissues were significantly correlated and did not exceed 5 ng g^–1 dw. Among the studied genera the most contaminated by PAHs were <em>Ulva</em>, <em>Undaria</em> and <em>Cystoseira</em>. The highest concentrations of PCBs and pesticides were found in <em>Cystoseira</em>, <em>Fucus</em> and <em>Gracilaria</em>. The least contaminated genus was <em>Porphyra</em>. Although macroalgal specimens were sampled in differently contaminated areas placed from the mainland to the Lido Lagoon mouth, no quantitatively meaningful differences of concentrations were found among the sampling stations.</p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00052-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56209395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonality of internal gravity waves kinetic energy spectra in the Ligurian Basin","authors":"Hans van Haren ,&nbsp;Claude Millot","doi":"10.1016/S0399-1784(03)00062-8","DOIUrl":"10.1016/S0399-1784(03)00062-8","url":null,"abstract":"<div><p><span>In the central Ligurian Basin, Western Mediterranean Sea, dense water formation occurs in winter so that near-surface stratification displays a marked seasonality<span>. Consequently, kinetic energy spectra from the surface to intermediate depths are entirely different in summer and winter. In summer, the spectra show a peak near the local inertial frequency (</span></span><em>f</em>). The polarization of currents in the internal gravity wave frequency (σ) band (<em>f</em> &lt; σ &lt; <em>N, N</em> the buoyancy frequency) resembles internal wave theory (for <em>N</em> &gt;&gt; <em>f</em>). In winter, however, no significant near-inertial (or any other) spectral peak is observed and motions are not polarized at any frequencies, whatever the observation depths. With respect to the energy levels observed in summer, those in winter are enhanced at all frequencies (except near <em>f</em><span>). The seasonal pycnocline determines the summertime development of near-inertial and higher frequency internal waves, also at great depths (~1100 m at least). In winter, no near-surface pycnocline does exist and no (gravity nor gyroscopic) near-inertial internal waves occur; the observed currents are associated with strong mesoscale activity and dense water formation, not with local </span><em>N</em>. For the ‘internal wave band’ this implies a lack of scaling of horizontal kinetic energy with <em>N</em> that is reflected in changes of the spectral slope. In the coastal zone of the Ligurian Basin, especially near Corsica, where the alongslope circulation and an almost permanent stratification prevail, near-inertial currents are found yearlong, with only moderate changes in amplitude in the near-surface layer.</p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00062-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76166862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A numerical modelling study of upwelling filaments off the NW African coast","authors":"Ian Stevens,&nbsp;John Johnson","doi":"10.1016/S0399-1784(03)00049-5","DOIUrl":"10.1016/S0399-1784(03)00049-5","url":null,"abstract":"<div><p>A fine resolution (1/12° × 1/12°) primitive equation<span> limited area model is constructed for the region off NW Africa in the eastern North Atlantic to examine the generation of cool upwelling filaments. A seasonal shift in the trade wind<span><span> pattern leads to coastal upwelling and an equatorward coastal current. The filaments form at four preferred locations along the NW African coast between 25°N and 35°N, the largest filament being at Cape Ghir. The generation mechanism for the filaments is similar to the one proposed for filaments in the California current system. As a result of baroclinic instability meanders develop on the coastal current and transport cool upwelled water offshore to form the filaments. During the relaxation phase of the upwelling a cyclonic eddy is generated to the south of the Cape Ghir plateau which serves to intensify the offshore jet at this location and leads to </span>downwelling within the filament.</span></span></p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00049-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86832507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution et écologie des Méduses (Cnidaria) du golfe de Tunis (Méditerranée sud occidentale)","authors":"M.N Daly Yahia ,&nbsp;J Goy ,&nbsp;O Daly Yahia-Kéfi","doi":"10.1016/j.oceact.2003.05.002","DOIUrl":"10.1016/j.oceact.2003.05.002","url":null,"abstract":"<div><p>The Medusae of Tunis Gulf (25 species) are qualitatively the third zooplanktonic group after Tintinnids and Copepods. Anthomedusae (eight species), Trachymedusae (five species) and Leptomedusae (four species) represent the major part among the 20 species of Hydromedusae identified during our study (December 1993–November 1995). However, the Limnomedusae (two species) and the Narcomedusae (one species) are poorly represented. In the Bay of Tunis, <em>Obelia</em> spp., the most common and dominant species, command the quantitative fluctuations of Hydromedusae and reach exceptionally the density of 25 800 ind. m^–3. Within the Scyphomedusae (five species), <em>Pelagia noctiluca</em> is the most common species which outbreaks in winter and autumn. Tunis Gulf seems to be composed of two jellyfish communities; the first one is composed of endogenous species showing a constant period of blooming like <em>Olindias, Cladonema, Aurelia, Cotylorhiza</em> and <em>Rhizostoma</em> and sometimes permanent like <em>Obelia</em> spp. and <em>Clytia</em> spp.; the second is represented by exogenous species considered as “visitors” like <em>Velella, Sminthea</em> or <em>Pelagia</em> whose presence on the coast is dependent on local and particular winds and currents.</p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.oceact.2003.05.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82586666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Holocene multisource material input into the Aegean Sea: depositional and post-depositional processes","authors":"Pierre Giresse ,&nbsp;Roselyne Buscail ,&nbsp;Bruno Charrière","doi":"10.1016/j.oceact.2003.09.001","DOIUrl":"10.1016/j.oceact.2003.09.001","url":null,"abstract":"<div><p>The upper ~50 cm sediments in the deep-sea Aegean Sea were generally deposited through hemipelagic rain as indicated by paucity of terrigenous sand-sized particles, abundance of clay-sized materials and lack of turbiditic beds. However, quartz sand-sized grains, black debris, higher C org content and C/N ratio attest to a significant river-borne supply in the North Aegean Trough. Recurrent gravity-induced transfers from the shelf break are evidenced through various markers of coastal deposition dating back the last low-stand (<em>Characea</em> oogons, <em>Elphidium crispum, Ammonia beccarii</em>, glauconitic grains, evolved organic matter). Especially, this deposition induced significant rise of the C/N ratio of successive layers. The top of ash layers of the Minoan eruption was reached in several sample cores giving opportunity for an estimation of sedimentation rate. The rate values (7–15 cm per kyear) in the southern basin are not significantly lower than those (4–23 cm per kyear) in the northern basin in spite of a lower terrigenous supply. This is due to the abundance of cemented Mg-calcite clasts and nodules throughout the cores of the Cretan Basin and North Skiros Basin rising the carbonate content up to 60%. It is suggested that this high carbonate concentration participates in the relative preservation of the most labile components of the organic matter in a large southern part of the basin characterised by low C/N ratio (5.5–8). Around 2000–1200 year BP, thin darks layers were deposited and are not yet completely oxidised. They would attest to a very beginning stage of sapropelic sediment formation during times of stagnant bottom water probably related to the enhanced Black Sea water circulation.</p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.oceact.2003.09.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"55033171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial organisation of macrozoobenthic communities in response to environmental factors in a coastal lagoon of the NW African coast (Merja Zerga, Morocco)","authors":"Hocein Bazaïri ,&nbsp;Abdellatif Bayed ,&nbsp;Michel Glémarec ,&nbsp;Christian Hily","doi":"10.1016/S0399-1784(03)00041-0","DOIUrl":"https://doi.org/10.1016/S0399-1784(03)00041-0","url":null,"abstract":"<div><p><span><span>Merja Zerga lagoon, located on the Moroccan Atlantic coast, is a site of international value (Ramsar Site) in terms of its ornithological diversity. However, the lagoon is heavily exploited for its clams and fishes. In an effort to further understanding of lagoon ecosystems, and thus to facilitate the management and conservation of their resources, an ecological survey of its benthic component was carried out. Benthos is a valuable food source for birds, fishes and humans. This work involved identifying the macrozoobenthic communities in the lagoon and assessing their spatial distribution. The study was based on monthly sampling of the </span>intertidal zone<span> and seasonal sampling in subtidal zone, over a one-year period. In the intertidal zone, salinity<span> and median diameter and silt content of the sediment exhibited a gradient extending from the entrance to the inner lagoon, according to tidal flow. Sediment grain size characteristics reflected a gradual decrease of tidal currents from the lagoon entrance towards the inner parts of the lagoon, i.e. silt content increased with distance from the entrance. In the subtidal zone, the tidal currents were fairly strong throughout the lagoon, leading to the presence of coarser sediments than in the intertidal zone. Based on these physical, chemical and substratum characteristics, three communities were identified: (i) </span></span></span><span><em>Cerastoderma</em><em> edule</em></span> and (ii) <em>Scrobicularia plana</em> communities were located in both the intertidal and subtidal zones; and (iii) a <em>Tapes decussata</em><span><span> community that was only found in the subtidal zone. The assemblages in the subtidal zone were more diverse and the mean abundances of the constituent species were higher than in the intertidal zone, which is an interesting feature for a lagoon environment. Communities were distributed along an ecological gradient, without showing a discontinuity or ecotone. The lagoon functioned like an estuary in which the community structure was controlled by </span>edaphic factors in the intertidal zone, and by the hydrological factors in the subtidal zone.</span></p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00041-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92078367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modélisation des flux sédimentaires charriés dans la baie du Mont-Saint-Michel (Manche, France)","authors":"A Ehrhold ,&nbsp;S Guillou ,&nbsp;J.P Auffret ,&nbsp;T Garlan ,&nbsp;K Dan Nguyen","doi":"10.1016/S0399-1784(03)00039-2","DOIUrl":"10.1016/S0399-1784(03)00039-2","url":null,"abstract":"<div><p>A study of the sediment bedload in the Mont-Saint-Michel bay is presented here. It combines the use of a 2DH numerical model and a pattern of sediment bedload transport established on the analysis of the statements of sidescan imagery combined with a dense groundwork of sedimentary grab samples. Results show the role of tidal currents asymetry in the realistic bioclastic sand transfert from the subtidal environment to the coast and the divergence of sedimentary dynamic between the maritime bay to the West and the tidal delta to the East. This in-shore transfer is responsable of the Holocene prism construction. The model reproduces tidal sedimentary dynamics with the immediate surroundings of the Mont-Saint-Michel. It shows the interest of the modeling of bedload flows in the reconstitution of the sedimentary processes in the filling bays of Manche-Atlantic coast.</p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00039-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87575050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of two tagging techniques for Sarpa salpa: external attachment and intraperitoneal implantation","authors":"Catherine Jadot","doi":"10.1016/S0399-1784(03)00044-6","DOIUrl":"10.1016/S0399-1784(03)00044-6","url":null,"abstract":"<div><p>For a given species in a particular environment, the success and the harmlessness of transmitter attachment appear to be highly specific. As no information was available for the tagging of the strepie, <span><em>Sarpa salpa</em></span>, a suitability study of attachment techniques was needed. Two types of transmitter attachments were investigated: (1) externally, placed on the back of the fish below the dorsal fin by means of two threads sutured through the dorsal musculature, and (2) internally, in the peritoneal cavity. Twenty-five fish were monitored over a 14-d period for survival, surgical healing, injury occurrence and post-tagging behaviour. Even though we observed a 100% survival rate for both groups, with no noticeable buoyancy or swimming alteration, findings from this study indicate that both groups of tagged fish were affected by the presence of the transmitter in different ways. Fish with an external transmitter were chronically affected, incurring physical impact, whereas the surgically-implanted fish exhibited short-term tagging effects (less than 36 h), attributable to surgery effects, and were not subject to fouling on transmitter or wound chafing. Moreover, they appeared to recover quickly with no indication of long-term effects. Based on the findings of this study, the use of the surgical implantation method for <em>Sarpa salpa</em> is recommended.</p></div>","PeriodicalId":100980,"journal":{"name":"Oceanologica Acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0399-1784(03)00044-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86038278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}