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Climate Change and Its Influence on Microbial Diversity, Communities, and Processes
Published in Javid A. Parray, Suhaib A. Bandh, Nowsheen Shameem, Climate Change and Microbes, 2022
Irteza Qayoom, Haika Mohi-Ud-Din, Aqsa Khursheed, Aashia Altaf, Suhaib A. Bandh
Increased surface water temperature as a result of climate warming enhances the stratification. It decreases the thickness of the upper mixing layer (UML), which results in nutrient depletion due to the partial upwelling of nutrients from deep water layers (Hader and Gao, 2017). Decreased availability of nutrients with elevated UV exposure to phytoplankton may have consequences on phytoplankton productivity (Gao et al., 2012 b) and community assemblages (Beardall et al., 2009). Since phytoplankton is the basis of the food web, any shift in their community will result in the reduction of energy transfer efficiency in the food chain, which consequently weakens the functioning of an aquatic ecosystem (Acevedo-Trejos et al., 2015; Li et al., 2016). Climate change can also indirectly affect phytoplankton through the increase of grazing pressure by heterotrophs, which strongly disturb the community composition, diversity, and temporal dynamics of phytoplankton (Winder and Sommer, 2012).
Lakes and Reservoirs: Pollution
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Water Resources and Hydrological Systems, 2020
Subhankar Karmakar, O.M. Musthafa
Stratification is a significant feature influencing water quality in reasonably stagnant, deep waters, such as lakes and reservoirs, which occurs mainly because of the difference in temperature, leading to a variation in density. Occasionally, it can be due to the difference in solute concentrations. Water quality in various layers of stratified water body is subjected to different influences. Solar insolation will be more in the upper layer while the lower layer is physically detached from the atmosphere and may be in touch with decaying sediments that exert an oxygen demand. Because of these varying influences, the lower layer will usually have a reduced oxygen concentration relative to the upper layer. The anoxic condition thus produced will enhance the diffusion of constituents from sediments and form various compounds such as ammonia, nitrate, phosphate, sulfide, silicate, iron, and manganese.
Environmental Effects of Energy Production and Utilization
Published in Efstathios E. Michaelides, Energy, the Environment, and Sustainability, 2018
A detrimental effect to lakes from thermal pollution is stratification, which is caused by withdrawing colder water from the bottom of the lake and adding warmer water to the top layer. Because the warmer water is lighter, it remains at the surface and restricts mixing by convection. This process impedes the natural mixing of the layers of the lake, the transfer of nutrients from the bottom of the lake (hypolimnion) to the top layer (epilimnion), and the transfer of oxygen to the bottom layer. In addition, water taken from the bottom layer brings to the top algae nutrients, phosphorus, and nitrogen. Several species of algae, especially those that are tolerant to high-temperatures, may increase uncontrollably at the top layer of the lake. Some of these algae are toxic to fish, and when they die, the organisms that decompose them compete for the available dissolved oxygen with the remaining fish population. The result is a (sometimes severe) decrease in the fish population at the top layer of the lake. The detrimental effects of the stratification process may be intensified if the lake receives high quantities of algae nutrients from agricultural waste or sewage discharge that stimulate the uncontrolled growth of algae. This series of processes is called lake eutrophication.
Cattaneo – Christov heat and mass flux model for Electromagnetohydrodynamic (EMHD) non-Newtonian flow of Jeffrey nanofluid with nonlinear thermal radiation and stratified boundary conditions
Published in Waves in Random and Complex Media, 2023
Dibyendu Saha, Anindita Mahanta, Swati Mukhopadhyay, Sanjib Sengupta
Stratification of fluids is a natural process that is nothing but the formation of layers and occurs due to temperature differences and concentration differences or fluids with different densities. Stratification generates a transition zone of a temperature gradient between hotter and colder regions of fluid. Stratification plays a major role in lakes and ponds, as it mandates temperature and concentration differences of hydrogen and oxygen which in turn may affect various species of that environment. Thermal stratification is prominent for its implications in solar engineering as it can forecast the possibilities of realizing higher energy efficiency. Results of [41] show that an increase in thermal stratification decreases the wall temperature and it has a substantial influence on the temperature distribution in the flow near the wall. Worth mentioning work in the field is done by [42].
Bottom topography influence on wave transformation by a porous-flexible membrane in a two-layer oblique sea
Published in Waves in Random and Complex Media, 2022
Referring to fluid stratification, the statistical report of Li et al. [25] establish a fact of the substantial increase in stratification globally for the following decades 1960–2018. This stratification occurs largely because of changing temperature and salinity. Such changes account for significant variations of density of the fluids in the vertical direction, which finally lead to fluid oscillation. The wave phenomena related to such oscillations are called internal/interface waves. A comprehensive study on the propagating internal waves and their significance is well-reviewed by Massel [26]. The effect of the internal wave is well demonstrated by Manam and Sahoo [27] in their report of paramount resistance by the porous structure due to internal waves in a stratified fluid. In that article, they examined the radiation and scattering of oblique waves by the thin porous structure in two-fluid of finite and infinite depths, by means of Havelocks expansion. Kumar et al. [28] further extended their study with the flexible porous membrane by using the least square approximation. Apart from the phenomenon of ocean stratification, the other aspects of stratified media on wave propagation can be found in [29], where Abo-Seida et al. [29] investigated the propagation of lateral electromagnics wave near the sea surface using a three-layered model. Latter, Abo-Seida et al. [30] studied the behavior of propagating such waves in cylinder filled-up with inhomogeneous plasma.
The significance of exponential space-based heat generation and variable thermophysical properties on the dynamics of Casson fluid over a stratified surface with non-uniform thickness
Published in Waves in Random and Complex Media, 2022
Tosin Oreyeni, Nehad Ali Shah, Amos Oladele Popoola, Essam R. Elzahar, Se-Jin Yook
Stratification is a natural or scientific phenomenon that describes the layering of bodies of water as a result of temperature and concentration changes. The stratification concept is used in various energy storage applications, such as thermal energy storage systems or solar thermal utilization systems to store cold and warm water in the same tank and to separate the two distinct masses of water using a thin layer thermocline. Recently, Khan et al. [1] discussed thermal and solutal stratification effects on the chemically reactive flow of hyperbolic tangent fluid. Dawar et al. [2] studied a new MHD non-homogeneous convective nanofluid flow model for simulating a rotating inclined thin layer of sodium alginate-based Iron oxide exposed to incident solar energy. The effect of stratification on the nonlinear radiative flow of nanofluid was presented by Khan et al. [3]. Luo and Wang [4] examined Atwood number and stratification parameter influence on compressible multi-mode Rayleigh-Taylor instability. Micropolar nanofluid flow over Riga plate with stratification was analyzed by Rafique et al. [5]. Oreyeni and Omokhuale [6] considered an analytic approach of free convection flow of thixotropic fluid subjected to thermal stratification. The joint impact of nonlinear thermal radiation and thermal stratification on a micropolar fluid flow past a surface was checked by Koriko et al. [7]. Koriko et al. [8] discussed the dynamics of buoyant convective flow of a micropolar fluid under the subjection of thermal stratification. It was reported that the presence of stratification corresponds to reduction in the velocity and temperature of the fluid.