Influence of Solar Physics Factors on the Spring Growth of Phytoplankton in Reservoir

2017 ◽  
Vol 6 (2) ◽  
pp. 19-27
Author(s):  
Корсак ◽  
M. Korsak ◽  
Мошаров ◽  
Sergey Mosharov ◽  
Скоробогатов ◽  
...  
Keyword(s):  
Water Treatment ◽  
Solar Radiation ◽  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
Solar Physics ◽  
Wolf Number ◽  
Total Solar Radiation ◽  
The Sun ◽  
Good Correspondence ◽  
Spring Phytoplankton Bloom

The article gives the results of retrospective statistical analysis, which justify the presence of statistical dependencies between the dates of the beginning and the peak values of the spring phytoplankton bloom in the Uchinsk reservoir and the intensity of total solar radiation in the range of photosynthetically active radiation (PAR), as well as the value of the integral indices of the activity of the Sun (Wolf number), in the period preceding of phytoplankton bloom. It is found, that the greater the magnitude of the fluxes of solar radiation in the PAR range will get the surface of the reservoir for 28 days of February this year, the later will be observed peaks of the spring phytoplankton bloom.A positive correlation between the parameters of the light regime (the sum of PAR) and the period of the onset of the algae “bloom” in the reservoir is apparently related to the photoinhibition of phytoplankton development directly under the ice, which leads to a later development of the spring “bloom”.The verification of the obtained regression equation showed a good correspondence of actual and calculated dates of spring “bloom” for a ten-year period. A negative correlation was found between the values of Wolf numbers (in February and the average annual values of the current year) and the dates of the spring peaks of phytoplankton bloom, which can be explained by the stimulating nature of the effect of the intensity of natural magnetic fields on the development of phytoplankton.The results of the investigations are of undoubted interest for the analysis of the influence of the light factor and the integral activity of the Sun on the seasonal dynamics of phytoplankton in the reservoir, as well as for an accurate forecast of the onset of spring phytoplankton bloom in drinking-water reservoirs in planning water treatment and water treatment activities.

scholarly journals Theoretical study of Linke's Turbidity at Some Iraqi Sites Based on Solar Radiation

2021 ◽  
Vol 13 (01) ◽  
pp. 12-23
Author(s):  
Ali Shkhair Younus ◽  
◽  
Sahib Neamh Abdul Wahid ◽  
Keyword(s):  
Solar Radiation ◽  
Winter Season ◽  
Total Solar Radiation ◽  
The Sun ◽  
Average Amount ◽  
Diffuse Solar Radiation ◽  
The North ◽  
The Hours ◽  
South Of Iraq ◽  
North And South

Turbidity was calculated by solar irradiance (Linke's Turbidity) for sixteen Iraqi sites. These sites were distributed among middle, north and south of Iraq. We have updated these results of turbidity by depending on direct solar radiation, diffuse solar radiation, total solar radiation, and solar constant as inputs for mathematical models in computer programs. The latter calculations taking into account the hours of actual sun shine, hours of theoretical sun shine of the sun, the angle of the sun's rays, and the angle of the sun during the months of the year. The results showed that turbidity in the Iraqi sites which considered in this research depends mainly on the months of the year regardless of the fact that this site is located in the north, middle or south of Iraq. The amount of turbidity is at its greatest value during the winter season, specifically the month of December, where the average turbidity varied for those sites. In latter month the turbidity was ranged from (4.85 to 5.73), while in January it ranged from (4.75 to 5.72), then it began to decrease until the value of turbidity in most sites reached its lowest level in September, where the average turbidity of the studied sites varied (except for the site of Najaf) in this month (2.82 - 3.10) While the Najaf site was unique in registering the lowest average amount of turbidity in June by (3.25). The results showed that the turbidity in all sites included in this research ranges between (2.82 - 5.73) during the year.

scholarly journals A newly observed physical cause of the onset of the subsurface spring phytoplankton bloom in the southwestern East Sea/Sea of Japan

2014 ◽  
Vol 11 (5) ◽  
pp. 1319-1329 ◽  
Author(s):  
Y.-T. Son ◽  
K.-I. Chang ◽  
S.-T. Yoon ◽  
T. Rho ◽  
J. H. Kwak ◽  
...  
Keyword(s):  
Sea Of Japan ◽  
Mixed Layer ◽  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
Mixed Layer Depth ◽  
East Sea ◽  
Ulleung Basin ◽  
Intermediate Water ◽  
Spring Phytoplankton Bloom ◽  
Bloom Period

Abstract. An ocean buoy, UBIM (Ulleung Basin Integrated Mooring), deployed during the spring transition from February to May 2010 reveals for the first time highly resolved temporal variation of biochemical properties of the upper layer of the Ulleung Basin in the southwestern East Sea/Sea of Japan. The time-series measurement captured the onset of subsurface spring bloom at 30 m, and collocated temperature and current data gives an insight into a mechanism that triggers the onset of the spring bloom not documented so far. Low-frequency modulation of the mixed layer depth ranging from 10 m to 53 m during the entire mooring period is mainly determined by shoaling and deepening of isothermal depths depending on the placement of UBIM on the cold or warm side of the frontal jet. The occurrence of the spring bloom at 30 m is concomitant with the appearance of colder East Sea Intermediate Water at buoy UBIM, which results in subsurface cooling and shoaling of isotherms to the shallower depth levels during the bloom period than those that occurred during the pre-bloom period. Isolines of temperature-based NO3 are also shown to be uplifted during the bloom period. It is suggested that the springtime spreading of the East Sea Intermediate Water is one of the important factors that triggers the subsurface spring bloom below the mixed layer.

The Advent of the Spring Bloom in the Eastern Subarctic Pacific Ocean

1966 ◽  
Vol 23 (4) ◽  
pp. 539-546 ◽  
Author(s):  
T. R. Parsons ◽  
L. F. Giovando ◽  
R. J. LeBrasseur
Keyword(s):  
Pacific Ocean ◽  
Primary Production ◽  
Mixed Layer ◽  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
Central Area ◽  
Critical Depth ◽  
Spring Phytoplankton Bloom ◽  
Subarctic Pacific ◽  
Subarctic Pacific Ocean

The spring phytoplankton bloom in the eastern subarctic Pacific Ocean was described from estimations of the critical depth and the depth of the mixed layer. The results suggested that the spring bloom begins during February in the area south of 45°N and east of 135°W. During March the bloom area advances in a northwesterly direction to 50°N at 125°W and 45°N at 135°W. A net increase in primary production is also possible during March near 55°N and 155°W. During April, the spring bloom is generally well established throughout the region except in a central area where suitable conditions are not firmly established until May. This description is supported by the distribution of copepods in the region during April.

The role of wind in determining the timing of the spring bloom in the Strait of Georgia

2009 ◽  
Vol 66 (9) ◽  
pp. 1597-1616 ◽  
Author(s):  
A. Kathleen Collins ◽  
Susan E. Allen ◽  
Rich Pawlowicz
Keyword(s):  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
Meteorological Data ◽  
Mixing Layer ◽  
Biophysical Model ◽  
Physical Factors ◽  
Freshwater Flux ◽  
Layer Depth ◽  
Spring Phytoplankton Bloom ◽  
Strait Of Georgia

A coupled biophysical model of the Strait of Georgia (SoG), British Columbia, Canada, has been developed and successfully predicts the timing of the spring phytoplankton bloom. The physical model is a one-dimensional vertical mixing model, using a K-profile parametrization of the boundary layer, forced with high frequency meteorological data. The biological model includes one phytoplankton class (microphytoplankton) and one nutrient source (nitrate). The spring bloom in the SoG occurs when phytoplankton receive enough light that their growth rates exceed their loss rates. The amount of light that the phytoplankton receive is a function of solar radiation and the depth of mixing. The model was used to determine what physical factors are controlling the phytoplankton losses and the light received by the phytoplankton. Wind was found to control the spring bloom arrival time, with strong winds increasing the mixing-layer depth and delaying the bloom. The amount of incoming solar irradiance, through amount of cloud cover, had a secondary effect. The freshwater input (primarily Fraser River discharge) had an insignificant effect on the timing. Increased freshwater flux increases the buoyancy flux and thus decreases the mixing-layer depth but also increases the strength of the estuarine circulation, increasing the advective loss.

scholarly journals Characterizing upper-ocean mixing and its effect on the spring phytoplankton bloom with in situ data

2015 ◽  
Vol 72 (6) ◽  
pp. 1961-1970 ◽  
Author(s):  
Sarah R. Brody ◽  
M. Susan Lozier
Keyword(s):  
Mixed Layer ◽  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
Upper Ocean ◽  
Late Winter ◽  
Uniform Density ◽  
Spring Phytoplankton Bloom ◽  
In Situ Data ◽  
Active Mixing

Abstract Since publication, the Sverdrup hypothesis, that phytoplankton are uniformly distributed within the ocean mixed layer and bloom once the ocean warms and stratifies in spring, has been the conventional explanation of subpolar phytoplankton spring bloom initiation. Recent studies have sought to differentiate between the actively mixing section of the upper ocean and the uniform-density mixed layer, arguing, as Sverdrup implied, that decreases in active mixing drive the spring bloom. In this study, we use in situ data to investigate the characteristics and depth of active mixing in both buoyancy- and wind-driven regimes and explore the idea that the shift from buoyancy-driven to wind-driven mixing in the late winter or early spring creates the conditions necessary for blooms to begin. We identify the bloom initiation based on net rates of biomass accumulation and relate changes in the depth of active mixing to changes in biomass depth profiles. These analyses support the idea that decreases in the depth of active mixing, a result of the transition from buoyancy-driven to wind-driven mixing, control the timing of the spring bloom.

scholarly journals The onset of the spring phytoplankton bloom in the coastal North Sea supports the Disturbance Recovery Hypothesis

2021 ◽  
Author(s):  
Ricardo González-Gil ◽  
Neil S. Banas ◽  
Eileen Bresnan ◽  
Michael R. Heath
Keyword(s):  
North Sea ◽  
Phytoplankton Biomass ◽  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
Biomass Accumulation ◽  
Coastal Areas ◽  
Rate Of Change ◽  
Winter Solstice ◽  
Spring Phytoplankton Bloom ◽  
Disturbance Recovery

Abstract. The spring phytoplankton bloom is a key event in temperate and polar seas, yet the mechanisms that trigger it remain under debate. Some hypotheses claim that the spring bloom onset occurs when light is no longer limiting, allowing phytoplankton division rates to surpass a critical threshold. In contrast, the Disturbance Recovery Hypothesis (DRH) proposes that the onset responds to an imbalance between phytoplankton growth and loss processes, allowing phytoplankton biomass to start accumulating, and this can occur even when light is still limiting. Although many studies have shown that the DRH explains the spring bloom onset in oceanic waters, it is less certain whether and how it also applies to coastal areas. To address this question at a coastal location in the Scottish North Sea, we combined 21 years (1997–2017) of weekly in situ data with meteorological information. The onset of phytoplankton biomass accumulation occurred around the same date each year, 16 ± 11 days (mean ± SD) after the winter solstice, when light limitation for growth was strongest. Also, negative and positive biomass accumulation rates (r) occurred respectively before and after the winter solstice at similar light levels. The seasonal change from negative to positive r was mainly driven by the rate of change in light availability rather than light itself. Our results support the validity of the DRH for the studied coastal region and suggest its applicability to other coastal areas.

Effect of Tracking Flat Reflector Using Novel Auxiliary Drive Mechanism on the Performance of Stationary Photovoltaic Module

2007 ◽  
Author(s):  
Sudhir Kulkarni ◽  
Saurabh Tonapi ◽  
Pierre Larochelle ◽  
Kunal Mitra
Keyword(s):  
Power Generation ◽  
Solar Radiation ◽  
Total Solar Radiation ◽  
The Sun ◽  
Drive Mechanism ◽  
Diffuse Solar Radiation ◽  
Pv Array ◽  
Pv Module ◽  
Continuous Power ◽  
Spherical Mechanism

General ways of cost reduction in solar power generation are Solar Tracked Photovoltaic (PV) arrays and concentrator systems. The PV array tracking becomes infeasible with increase in the size of the array and concentrated system is ineffective for continuous power generation as it requires external cooling system. Proposed approach here is to employ a novel auxiliary mirror drive mechanism to track the sun and reflect the rays on to stationary PV arrays. The performance is compared with same PV module without reflector under the same environmental conditions. Solarex SX 38 PV module and cleardome solar reflector (96% reflectivity) are used for the experiments. PV module is connected to electrical load through Maximum Power Point Tracker (MPPT) and data acquisition system for voltage and current measurements. Incident radiation is measured using Li-Cor pyranometers located on the plane of the module and horizontal plane. A shadow band device is used for the measurement of diffuse solar radiation. The PV module is placed facing south at a tilt angle equal to the latitude angle. A reflector is placed facing north and oriented using the novel Mirror Positioning Device (MPD). The MPD is a five bar spherical mechanism used for solar tracking. This mechanism has two degrees of freedom which allows for tracking the sun along its azimuth and altitude. The mechanism is driven by two servo motors which actuate two links. The actuated link 1 helps in achieving the altitude gained by the sun while the actuated link 2 helps to attain the azimuth (or horizontal movement). The reason for using a spherical mechanism is due to the virtue of its architecture; it allows for carrying a larger payload and also helps in reducing weight. Its advantages are that it requires less power than traditional PV array tracking; there is no need for sensors to determine the position of the sun and also that it being a two degree of freedom spherical mechanism yields a large singularity free mirror orienting workspace. Solar radiation, efficiency, and temperature are plotted as a function of time for analysis. Average diffuse solar radiation is found to be in the range of 15 to 20% of total solar radiation. Different experiments are performed to find out the optimum cycle speed for reflector. Measurements show that output from the PV panel can be increased in the order of 22% with the use of tracking reflector. This work has succeeded in its goal in realization that the considerable increase in output power from PV modules can be achieved.

scholarly journals THE NATURE OF THE SOLAR ENERGY SOURCE

2021 ◽  
Vol 21 ◽  
pp. 29-31
Author(s):  
P.D. Solozhentsev ◽  
Keyword(s):  
Energy Source ◽  
Solar Wind ◽  
Solar Radiation ◽  
Solar Energy ◽  
Nuclear Reactions ◽  
Solar Physics ◽  
Scientific Evidence ◽  
Low Energy ◽  
The Sun ◽  
Open Cycle

In solar physics as a result of studies of solar radiation and solar wind Scientists have raised a number of questions. A modern view of the structure of the Sun according to which its core is reacting thermonuclear fusion and solar luminosity energy from the photosphere, does not provide scientifically based answers to them. The article sets out the preliminary scientific evidence of the hypothesis new solar Luminous Energy Source open cycle low-energy nuclear reactions (LENR), entering the photosphere. Based on the physics of nuclear reactions of this cycle answers to questions raised.

Seasonal Variation of the Chlorophyll a:Pheopigment Ratio in the Gulf of St. Lawrence

1974 ◽  
Vol 31 (7) ◽  
pp. 1263-1268 ◽  
Author(s):  
C. Spence ◽  
D. M. Steven
Keyword(s):  
Seasonal Variation ◽  
Primary Production ◽  
Chlorophyll A ◽  
Annual Cycle ◽  
Spring Bloom ◽  
Phytoplankton Bloom ◽  
Zooplankton Biomass ◽  
Spring Phytoplankton Bloom ◽  
Rate Of Growth ◽  
Close Relationship

Measurements of the chlorophyll a:pheopigment ratio from all parts of the Gulf of St. Lawrence showed a close relationship between changes in the ratio and the annual cycle of primary production. The chlorophyll a fraction was greatest at the time of the spring phytoplankton bloom and was lowest during the winter. Differences in the timing of the spring bloom from year to year and between regions of the Gulf indicated that changes in the chlorophyll a:pheopigment ratio were determined primarily by the rate of growth of phytoplankton and were due mainly to variation in the amount of chlorophyll a. No relationship was found between the amount of pheopigment and zooplankton biomass.

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