scholarly journals Cold water temperature anomalies on the Sodwana reefs and their driving mechanisms

2021 ◽  
Vol 117 (9/10) ◽  
Author(s):  
Calvin Wells ◽  
Justin Pringle ◽  
Derek Stretch

The Sodwana reef system experiences short-term temperature fluctuations that may provide relief from bleaching and be crucial in the future survival of the system. These temperature fluctuations are best described as cold water temperature anomaly events that occur over a period of days and cause a drop in temperature of a few degrees on the reef. We explored the statistical link between the temperature anomalies and the regional hydrodynamics to elucidate the driving mechanisms of the temperature anomalies around Sodwana. Temperature measurements taken between 1994 and 2015 on Nine‑Mile Reef at Sodwana show that temperature anomalies occur on average three times per year at Sodwana and predominantly during the summer months. A conditional average of altimetry data at the peak of the temperature anomalies showed the emergence of a negative sea surface height (SSH) anomaly pattern and associated cyclonic eddy just offshore of the Sodwana region. The cyclonic eddies associated with the temperature anomalies originate on the southwestern edge of Madagascar and migrate westwards until they interact with the African coastline at Sodwana. Instantaneous altimetry SSH fields over the 21-year period were cross-correlated to the conditionally averaged SSH field within a 2° region around Sodwana. It was found that 33% of the temperature anomalies at Sodwana were not associated with the presence of cyclonic eddy systems. This finding suggests that an offshore cyclonic eddy interacting with the shelf is not the sole driving mechanism of the temperature anomalies.

2018 ◽  
Vol 44 ◽  
pp. 00017 ◽  
Author(s):  
Agnieszka Chmielewska

The article discusses the influence of the cold water temperature on the amount of energy consumed for the purposes of the DHW preparation in multi-family buildings. The article begins with a presentation of the DHW consumption readings from a multi-family building, recorded on a monthly basis during the period of 4 years. The readings constituted the base for calculating the demand for energy for the purposes of the DHW preparation. Subsequently, basing on the output water temperature readings from the water treatment plant, it was proved that the temperature of the mains water fluctuates throughout the year. The review of the available literature, as well as the measurements, confirmed that it is necessary to develop a new model of the cold water temperature that would take into account the type of intake in a water treatment plant. The final part of the article presents how the accepted assumptions about the temperature of the mains water influence the consumption of energy for the purposes of the DHW preparation.


2012 ◽  
Vol 105 ◽  
pp. 47-60 ◽  
Author(s):  
Daisuke Takahashi ◽  
Akihiko Morimoto ◽  
Tetsuya Nakamura ◽  
Takuji Hosaka ◽  
Yoshihisa Mino ◽  
...  

2017 ◽  
Vol 124 ◽  
pp. 107-115 ◽  
Author(s):  
Julijana Bors ◽  
Katherine R. O’Brien ◽  
Steven J. Kenway ◽  
Paul A. Lant

2006 ◽  
Vol 84 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Carrie A MacKinnon ◽  
Anna Lawson ◽  
E D Stevens ◽  
Ronald J Brooks

We examined the thermal biology of free-ranging terrestrial eastern foxsnakes (Elaphe gloydi Conant, 1940) that were voluntarily swimming in cold water during spring, in Georgian Bay, Ontario, Canada. Using temperature-sensitive radiotelemetry, we recorded body temperatures of foxsnakes during 12 cold-water swims, and subsequent warming on shore. During these swims, water temperatures were from 11 to 22 °C and distances of 85–1330 m were travelled. Snakes that were in cold water long enough equilibrated with water temperature and did not maintain a body temperature above ambient. The largest observed drop in body temperature was 22.6 °C (over 11 min) and the largest increase was 23 °C (over 66 min). Such large, rapid temperature fluctuations have not previously been reported in detail from snakes in the field. Twice as many telemetry observations as expected occurred between 1200 and 1400, suggesting that snakes chose to swim midday. Additionally, our results suggest that foxsnakes bask to raise their body temperature prior to swimming in cold water. We compared swimming speed and the coefficient of temperature change among foxsnakes and other snake species. Swimming speed was positively correlated with water temperature, similar to other findings. We found no clear trend between mass and the coefficients of cooling and warming; however, snakes cooled in water 2.8–8.6 times faster than they warmed in air.


2019 ◽  
Vol 116 ◽  
pp. 00106 ◽  
Author(s):  
Miroslaw Zukowski

In the present work, results of experimental research on the mains water temperature supplying the Solar Domestic Hot Water system in the period from 2016 to 2018 are shown. The test object is located in the Hotel for Research Assistants on Bialystok University of Technology campus in Poland. One of the elements that will guarantee the correct energy balance of a hot tap-water system is the exact determination of the cold water temperature. The aim of this study is estimation of the temperature of the mains water flowing into the district heating substation and the water feeding directly the heat storage tanks. The research results showed that the average value of the cold water was 14.09°C during the 3 years of measurements. Moreover, it was shown that this temperature increased by about 0.4°C as a result of heat exchange with the air inside the substation. In the article, the author proposed modifications of coefficients in a commonly used model developed by National Renewable Energy Laboratory for determining the temperature of mains water in energy simulations. The proposed changes allow for accurate modelling of the cold water temperature under the climate conditions of north-eastern Poland.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4113 ◽  
Author(s):  
Kamil Pochwat ◽  
Sabina Kordana-Obuch ◽  
Mariusz Starzec ◽  
Beata Piotrowska

The growing interest in the use of unconventional energy sources is a stimulus for the development of dedicated devices and technologies. Drain water heat recovery (DWHR) units can be an example of such devices. They allow the recovery of part of the heat energy deposited in grey water. This paper describes the results of research on the assessment of the financial profitability of the use of two horizontal heat exchanger solutions, taking into account the actual distribution of cold water temperature during the operating year in the plumbing and two operating regimes of the premises as the residential and service facilities. The analysis showed that the use of a horizontal heat exchanger with increased efficiency in a dwelling in a 15-year life cycle allowed for achieving more than twice as much savings (reaching up to EUR 1427) compared to a classic horizontal heat exchanger. At the same time, it was shown that the installation of this type of equipment was more profitable the greater the water consumption of the premises. The article also notes the impact of cold water temperature in the installation on the results of the analysis. It was featured that taking temperature on the basis of installation design recommendations led to significant distortions in the financial analysis. On the other hand, comparing the method of averaging the cold water temperature (daily, monthly and yearly), it was determined that averaging the temperature over the annual cycle was an acceptable simplification of the model. The research results presented in the paper have a practical aspect and may constitute guidelines for designers and potential investors. In addition, they can be an incentive to continue research on heat exchangers by other scientific centers, which on a global scale will increase the universality of their use.


2017 ◽  
Vol 540 ◽  
pp. 19-26 ◽  
Author(s):  
Li Cui ◽  
Carl Goodwin ◽  
Wa Gao ◽  
Baoqiang Liao

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