Thermocline
Mostrando 1-12 de 14 artigos, teses e dissertações.
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1. Caracterização do acoplamento físico-biológico causado por ondas de Rossby baroclínicas / Characterization of physical-biological coupling caused by baroclinic Rossby waves
Ondas de Rossby do primeiro modo baroclínico em médias latitudes foram observadas em dados de anomalia da altura da superfície do mar dos radares altimétrico TOPEX/Jason-1 na última década. Entretanto, sinais similares são observados em dados de concentração de clorofila a obtidos através de dados na faixa espectral visível através do sensor SeaW
Publicado em: 2008
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2. Contributions to South Atlantic paleoceanography in the last 25,000 years: evidence from calcareous nannofossils from northeastern brazilian slope / Nanofósseis calcários da margem continental nordeste do Brasil: uma contribuição à paleoceanografia do Atlântico Sul nos últimos 25.000 anos
This study focuses on changes in calcareous nannofossil assemblages as an evidence of paleoceanographic variability during the last 25,000 years in two deep sea piston cores from the northeastern Brazilian continental margin. To support reconstructing ancient marine environment others proxies have been applied along with the calcareous nannofossil analysis:
Publicado em: 2007
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3. Study of the wind variation effects in the upwelling system along the Peruvian Coast through data analysis and numerical modeling / Estudo dos efeitos de variações do vento no sistema de ressurgência ao longo da costa peruana através da análise de dados e modelagem numérica
The objective of the present work was to study the effects of variability in the wind due to the El Niño-Southern Oscillation events in the surface circulation patterns of the Peruvian coast, by means of data analysis and numerical modeling. It is focused the period 1991-2000, when it was observed strong La Niña (1996-1997, 1998-2000) and El Niño events (
Publicado em: 2007
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4. DistribuiÃÃo e abundÃnia relativa de peixes e crustÃceos capturados no programa REVIZEE/Score-NE na plataforma externa e talude da costa do Nordeste do Brasil
From 27/10/1997 to 19/11/2000, as part of the REVIZEE1 Program, 27 exploratory fishing cruises were done along the external margin of the continental shelf and slope, off northeast Brazil, using bottom longline and traps as fishing gears. The relative abundance of the species caught was analyzed through the Catch per Unit of Effort (CPUE), as the number of s
Publicado em: 2005
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5. Fatores que influenciam na produtividade dos oceanos: a importÃncia do fluxo de difusÃo dos nutrientes para a biomassa do fitoplÃncton na regiÃo oceÃnica do nordeste brasileiro
In the tropical oceanic region the phytoplankton primary biomass is controlled by light availability and inorganic dissolved nutrients, besides other physical factors as turbulence and sedimentation. The water properties in the photic zone are subjected by a number of different forcing intensities opposite to the deeper waters which varies regularly. In Nort
Publicado em: 2003
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6. Nitrogen Fixation by the Photosynthetic Sulfur Bacterium Chlorobium phaeobacteroides from Lake Kinneret
N2 fixation by Chlorobium phaeobacteroides from Lake Kinneret was dependent on ammonia concentration and light intensity. In the thermocline of Lake Kinneret, N2 fixation and photosynthesis were low. It was concluded that the bacteria do not contribute significantly to the organic nitrogen load of the lake.
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7. Distribution and Identification of Luminous Bacteria from the Sargasso Sea
Vibrio fischeri and Lucibacterium harveyi constituted 75 of the 83 luminous bacteria isolated from Sargasso Sea surface waters. Photobacterium leiognathi and Photobacterium phosphoreum constituted the remainder of the isolates. Luminescent bacteria were recovered at concentrations of 1 to 63 cells per 100 ml from water samples collected at depths of 160 to 3
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8. On the cyclonic mean circulation of large lakes†
In large lakes, during the heating season, the combination of surface wind drift and solar heating results in the horizontal transport of some of the absorbed heat into the coastal zone. Large-scale vertical movements associated with alternating upwellings and downwellings distribute the heat over a deeper water mass than at mid-lake. As a result, the mean s
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9. ACETYLENE REDUCTION ASSAY FOR DETERMINATION OF PHOSPHORUS AVAILABILITY IN WISCONSIN LAKES*
Phosphorus-starved cells of Anabaena flos-aquae rapidly increase their capacity to reduce acetylene to ethylene when they receive phosphorus. This response may be used as a bioassay for detecting available phosphorus in aquatic ecosystems. The sensitivity of the method compares favorably with conventional methods for measuring dissolved orthophosphate, and h
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10. Determination of water mass properties of water pumped down from the Ekman layer to the geostrophic flow below
In a subtropical gyre, the convergent Ekman layer forces water downward into the geostrophic flow below. The properties and depth of the mixed layer vary considerably during the course of the year, but this variability does not penetrate into the geostrophic region. Evidently there is some process at work that selects only late winter water for actual net do
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11. Pulsed phytoplankton supply to the rocky subtidal zone: influence of internal waves.
Hydrographic measurements indicate that the thermocline and the phytoplankton-rich chlorophyll maximum layer are vertically displaced over a rocky pinnacle in the central Gulf of Maine by internal waves with maximum amplitudes of 27 m. Such predictable downwelling events are linked to rapid, 2- to 3-fold increases in chlorophyll a, an indicator of phytoplank
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12. Marine phosphate oxygen isotopes and organic matter remineralization in the oceans
We show that the isotopic composition of oxygen (δ18O) in dissolved inorganic phosphate (Pi) reveals the balance between Pi transport and biological turnover rates in marine ecosystems. Our δ18Op of Pi (δ18Op) measurements herein indicate the importance of cell lysis in the regeneration of Pi in the euphotic zone. Depth profiles of the δ18Op in the Atlan
National Academy of Sciences.