跳至主要内容

Dynamics of Primary Productivity and Oceanographic Parameters under Influence of the Amazon River Plume

Fluvial inflows carry significant amounts of nutrients, affecting especially continental platform regions, which act as a final recipient of these waters and have a major impact on the phytoplankton community structure. The dynamic structure resulting from this process is a mass of floating water with density lower than that of coastal waters, called a river plume.

Primary production and chlorophyll a concentrations are always dependent on synergistic effects among meteorological, physical, chemical and biological factors that limit or stimulate the activity of photosynthetic planktonic organisms. The aim of this work was to analyze the distribution of oceanographic parameters, chlorophyll a and primary productivity under the influence of the Amazon River plume, during the period of greatest extension of the Amazon plume.

Collections were carried out in the “Camadas Finas V” oceanographic campaign held in September/2014 at 16 stations along the continental shelf of the Amazon and adjacent oceanic region, aboard of the NHo 38 ship. At each station, surface vertical profiles (up to 400 m) of hydrodynamic, physical, chemical and biological parameters were measured. In addition, water samples were collected with Niskin bottles at the two depths selected for the determination of dissolved oxygen, nutrients, chlorophyll a and phytoplankton productivity.

The surface currents along the coast were of lower intensity in the northwest direction, while currents with higher intensities were observed in the east direction, mainly due to the retroflexion of the North Current of Brazil at this time of the year. The spatial influence of the plume was observed in the salinity, although the high precipitation in the region may also have contributed as a source of freshwater. However, the sampled region showed strong negative linear correlation of silicate, chlorophyll a and primary productivity with salinity. The primary productivity and chlorophyll a decreased their values as they moved away from the coast.

In conclusion, the Amazon River plume can reach and influence the oceanographic and biological parameters in a large area of this oligotrophic region. And the results also suggest that the export of material from the adjacent coastal region is a determinant factor of the productivity of the studied region, mainly due to the geographic extension of the plume of the Amazon River at this time of the year.

Article by Amanda Otsuka, et al, from Brazil and France.

Full access: http://mrw.so/4UHiAX

评论

发表评论

此博客中的热门博文

Electron Spin and Proton Spin in the Hydrogen and Hydrogen-Like Atomic Systems

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52202#.VIj7tMnQrzE Author(s) Stanisław Olszewski * Affiliation(s) Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland . ABSTRACT The mechanical angular momentum and magnetic moment of the electron and proton spin have been calculated semiclassically with the aid of the uncertainty principle for energy and time. The spin effects of both kinds of the elementary particles can be expressed in terms of similar formulae. The quantization of the spin motion has been done on the basis of the old quantum theory. It gives a quantum number n = 1/2 as the index of the spin state acceptable for both the electron and proton ...
发表评论
阅读全文

Remarks on the Complexity of Signed k-Domination on Graphs

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53574#.VMnXsCzQrzE Author(s)    Chuan-Min Lee 1 , Cheng-Chien Lo 1 , Rui-Xin Ye 2 , Xun Xu 2 , Xiao-Han Shi 2 , Jia-Ying Li 2 Affiliation(s) 1 Department of Computer and Communication Engineering, Ming Chuan University, The First American University in Asia, Taoyuan, Taiwan, Chinese Taipei . 2 Department of Electronic Information Engineering, Fuzhou University, Fuzhou, China . ABSTRACT This paper is motivated by the concept of the signed k-domination problem and dedicated to the complexity of the problem on graphs. For any fixed nonnegative integer k, we show that the signed k-domination problem is NP-complete for doubly chordal graphs. For strongly chordal graphs and distance-hereditary graphs, we show that the signed k-domination problem can be solved in polynomial time. We also show that the problem is linear-time solvable for trees, interval graphs, and chord...
发表评论
阅读全文

A Review of Technical Requirements for High Penetration of Wind Power Systems

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52361#.VJN8VcCAM4 Author(s)    Yuan-Kang Wu 1 , Tung-Ching Lee 2 , Ting-Yen Hsieh 2 , Wei-Min Lin 2 Affiliation(s) 1 Department of Electrical Engineering, National Chung-Cheng University, Chiayi, Taiwan . 2 Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan . ABSTRACT Renewable portfolio targets have been established in many regions around the world. Regional targets such as 20% renewable energy by year 2020 are not uncommon. As the levels of wind power penetration increase, there are many power system impacts. This work investigated possible challenges and technic...
发表评论
阅读全文