|
|
|
| Registros recuperados: 47 | |
|
|
| Schneider,Wolfgang; Fuenzalida,Rosalino; Garcés-Vargas,José; Bravo,Luis; Lange,Carina. |
| Recent high-resolution hydrographic measurements (1976-2001) from the eastern South Pacific (ESP) were employed combined with high-resolution data from the World Ocean Circulation Experiment to evaluate the vertical and horizontal extension of the OMZ (oxygen minimum zone, < 20 µmol kg-1) there. Of the six permanent hypoxic regions in the world oceans, the ESP OMZ is volumetrically the fourth largest, occupying 2.74 x 10(6) km³ and accounting for ~11% globally. Examples of variability in the vertical position of the OMZ in the water-column and also in its intensity offshore central Chile will be addressed. We conclude that the OMZ in the ESP is partly based on old, low-oxygen waters from intermediate depths of the North Pacific Ocean, which were further... |
| Tipo: Journal article |
Palavras-chave: Oxygen minimum zone; Dissolved oxygen; Coastal upwelling; Eastern South Pacific; Peru; Chile. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300016 |
| |
|
| |
|
|
| OLIVEIRA, M. D. de; CALHEIROS, D. F.; PADOVANI, C. R.. |
| Decoada ou dequada é o nome popular que se dá no Pantanal aos eventos anuais de alteração natural da qualidade da água durante a fase hidrológica de enchente, cuja intensidade varia de acordo com o clima e os padrões de inundação anuais. Ocorrem alterações das características físicas e químicas da água, que incluem mudanças para cor escura, depleção de oxigênio dissolvido (OD), chegando à anoxia, diminuição do pH (< 6,0) e aumento do CO2 Livre, de aproximadamente 20 mg/L para mais que 100 mg/L, podendo ocorrer expressivas mortandades de peixes dependendo da magnitude das alterações. Neste estudo mapeamos e descrevemos a área de ocorrência desses eventos no Pantanal, baseados nos dados de monitoramento de qualidade de água de 1988 a 2011, nas informações... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Decoada; Oxigênio dissolvido; Rio Paraguai; Mortandade de peixes; Decoada events.; Pantanal; Paraguay River; Dissolved oxygen; Fish kills.. |
| Ano: 2013 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/958791 |
| |
|
| |
|
|
| Labasque, Thierry; Chaumery, Christian; Aminot, Alain; Kergoat, Gilles. |
| The spectrophotometric iodine measurement for oxygen determination by the Winkler method is re-examined for theoretical and operational aspects. It is shown that the selection of an isobestic point for measuring the mixture of iodine and tri-iodide in the solution enhances reliability. The wavelength value of 466 nm was selected after a spectrum study. Then, performances are assessed by mean of statistical approach based on repeated standardization curves at the isobestic point compared with other wavelengths. At 466 nm, the method is linear up to about 1000 mumol kg(-1) of O-2. Optimization and validation of the spectrophotometric method is realized through a robustness study based on factors that may alter the results (temperature, reagent volumes,... |
| Tipo: Text |
Palavras-chave: Isobestic point; Sea water; Spectrophotometry; Dissolved oxygen. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-1694.pdf |
| |
|
| |
|
|
| Coppola, L.; Prieur, L.; Taupier-letage, I.; Estournel, C.; Testor, P.; Lefevre, D.; Belamari, S.; Le Reste, Serge; Taillandier, V.. |
| During the winter 2013, an intense observation and monitoring was performed in the north-western Mediterranean Sea to study deep water formation process that drives thermohaline circulation and biogeochemical processes (HYMEX SOP2 and DEWEX projects). To observe intensively and continuously the impact of deep convection on oxygen (O2) ventilation, an observation strategy was based on the enhancement of the Argo-O2 floats to monitor the offshore dense water formation area (DWF) in the Gulf of Lion prior to and at the end of the convective period (December 2012 to April 2013). The intense O2 measurements performed through shipborne CTD casts and Argo-O2 floats deployment revealed an O2 inventory rapidly impacted by mixed layer (ML) deepening on the month... |
| Tipo: Text |
Palavras-chave: Dense water formation; North-western Mediterranean Sea; Dissolved oxygen; Argo floats; Deep water ventilation. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00395/50594/51311.pdf |
| |
|
|
| Ciavatta, S.; Kay, S.; Saux-picart, S.; Butenschon, M.; Allen, J. I.. |
| This paper presents the first decadal reanalysis simulation of the biogeochemistry of the North West European shelf, along with a full evaluation of its skill, confidence, and value. An error-characterized satellite product for chlorophyll was assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The results showed that the reanalysis improved the model simulation of assimilated chlorophyll in 60% of the study region. Model validation metrics showed that the reanalysis had skill in matching a large data set of in situ observations for 10 ecosystem variables. Spearman rank correlations were significant and higher than 0.7 for physical-chemical variables (temperature, salinity, and oxygen),... |
| Tipo: Text |
Palavras-chave: Marine ecosystems; Data assimilation; Ocean color; Air-sea flux of carbon dioxide; Dissolved oxygen; Marine policy. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00383/49422/49850.pdf |
| |
|
| |
|
| |
|
|
| Menesguen, Alain; Dussauze, Morgan; Dumas, Franck; Thouvenin, Benedicte; Garnier, Valerie; Lecornu, Fabrice; Repecaud, Michel. |
| European directives (Water Framework Directive - WFD and Marine Strategy Framework Directive - MSFD) require a regular survey of several descriptors of the Environmental Status of coastal waters of the North-east Atlantic Ocean. Especially for the MSFD, which may concern large continental shelf areas where measurements are scarce, realistic ecological models can help assessing the Environmental Status. The ECO-MARS3D model of the pelagic ecosystem of the Bay of Biscay and English Channel continental shelf (NE Atlantic) has been developed for these applied purposes and validated against various types of historic data. This first paper deals with the basic biogeochemical version, which contains inorganic nutrients (NH4, NO3, PO4, Si(OH)4), three... |
| Tipo: Text |
Palavras-chave: Ecological 3D model; Continental shelf; Bay of Biscay and English Channel; Surface chlorophyll; Dissolved oxygen; MSFD. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00469/58098/60510.pdf |
| |
|
|
| Aminot, Alain; Kerouel, Roger. |
| During the cruises "SUROIT 1", "SUROIT 3" and "THALIA 1", many analyses of dissolved oxygen and chlorophyll have been carried out in order to ascertain some effects of oil spill of "AMOCO CADIZ" on oxygen concentrations and phytoplancton behaviour. These first results show an under-saturation of oxygen, four weeks after stranding, in sea-water standing between 10 to 20 milles eastward of "AMOCO CADIZ". These data allow to do some considerations about oxydation of hydrocarbons in sea-water. In estuaries, especially Aber Wrac'h, one of the most polluted, the analyses do not show obvious anomaly one month after oil spill. Quantitative results on chlorophyll "a" and phaeopigments don't seem to show any noticeable disturbance, neither off, nor near the coast,... |
| Tipo: Text |
Palavras-chave: Amoco Cadiz; Chlorophylle; Oxygène dissous; Manche; Amoco Cadiz; Chlorophyll; Dissolved oxygen; Engllsh Channel. |
| Ano: 1978 |
URL: http://archimer.ifremer.fr/doc/00306/41719/40930.pdf |
| |
|
| |
|
| |
|
|
| Ferreira, Joao G.; Andersen, Jesper H.; Borja, Angel; Bricker, Suzanne B.; Camp, Jordi; Da Silva, Margarida Cardoso; Garces, Esther; Heiskanen, Anna-stiina; Humborg, Christoph; Ignatiades, Lydia; Lancelot, Christiane; Menesguen, Alain; Tett, Paul; Hoepffner, Nicolas; Claussen, Ulrich. |
| In 2009, following approval of the European Marine Strategy Framework Directive (MSFD, 2008/56/EC), the European Commission (EC) created task groups to develop guidance for eleven quality descriptors that form the basis for evaluating ecosystem function. The objective was to provide European countries with practical guidelines for implementing the MSFD, and to produce a Commission Decision that encapsulated key points of the work in a legal framework. This paper presents a review of work carried out by the eutrophication task group, and reports our main findings to the scientific community. On the basis of an operational, management-oriented definition, we discuss the main methodologies that could be used for coastal and marine eutrophication assessment.... |
| Tipo: Text |
Palavras-chave: Eutrophication; Chlorophyll; Dissolved oxygen; Harmful algae; Marine; Coastal; Assessment methods; Europe; Marine Strategy Framework Directive; Water Framework Directive. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00039/15055/12609.pdf |
| |
|
| |
|
| |
|
| |
|
| |
|
|
| Mensi, F.; Ksouri, J.; Hammami, W.; Romdhane, M.S.. |
| L'algue rouge, Gracilaria verrucosa, a été cultivée, durant le printemps 2009, en mode suspendu à différents emplacements et profondeurs représentant les différences biogéochimiques de la lagune de Bizerte au Nord de la Tunisie. La concentration et la distribution des nutriments (ammonium, phosphate) dans l'eau, ainsi que la salinité, la température, l’oxygène et la transparence de l’eau ont été déterminées. Les méthodes analytiques internationales standardisées ont été appliquées. Les effets du mode de culture, de l’emplacement et de la profondeur sur les rendements en poids, protéines, R-Phycoérythrine et sucres totaux de l’algue ont été étudiés. La croissance de Gracilaria a été similaire dans les différents sites mais plus lente dans les profondeurs... |
| Tipo: Journal Contribution |
Palavras-chave: Algal culture; Ammonium compounds; Biochemical composition; Biogeochemistry; Carbohydrates; Dissolved oxygen; Environmental conditions; Growth; Intensive culture; Lagoons; Off-bottom culture; Raw materials; Red algae; Biogeochemical cycle. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/4497 |
| |
| Registros recuperados: 47 | |
|
|
|
