Intensification of water temperature increase inside the bottom cold water by horizontal heat transport

Abstract. A bottom cold water mass (BCWM) is a widespread physical oceanographic phenomenon in coastal seas, and its temperature variability has an important effect on the marine ecological environment. In this study, the interannual variation of the BCWM in Iyo-Nada (INCWM), a semi-enclosed bay in the Seto Inland Sea, Japan, from 1994 to 2015 and its influencing factors were investigated using monthly observational data and a hydrodynamic model. The interannual variation in water temperature inside the INCWM showed a negative correlation with the area of the INCWM, and positive correlations with the local water temperature from April to July and with remote water temperature below 10 m in an adjacent strait in July. Differing from previously studied BCWMs, which had interannual variations depending closely on the water temperature before the warming season, the interannual variation of INCWM depends strongly on the air-sea heat flux during the warming season via local vertical heat transport and lateral heat advection. Further, by comparing several BCWMs, we found that the BCWM size is a key factor in understanding the mechanisms responsible for the interannual variation of BCWMs in coastal seas. These findings will help to predict bottom water temperatures and improve the current understanding of ecosystem changes in shelf seas under global climate change.

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Unprecedented coastal upwelling in the southern coast of the Korean peninsula during summer 2013

10.5194/egusphere-egu2020-4384 ◽

2020 ◽

Author(s):

Jihun Jung ◽

Yang-Ki Cho

Keyword(s):

Water Temperature ◽

Sea Level ◽

Korean Peninsula ◽

Coastal Upwelling ◽

Cold Water ◽

Coastal Region ◽

Southern Coast ◽

Geostrophic Adjustment ◽

Long Time ◽

Bottom Cold Water

<p>Unprecedented coastal upwelling in the southern coast of the Korean peninsula was reported in the summer of 2013. The offshore water temperature was 2&#8451; higher than that of climate (10-year mean) due to the hot summer in 2013. However, the water temperature at the coastal region was 2&#8451; lower. The upwelling continued for a month despite of weakening of upwelling-favorable wind. In this study, observational data and numerical model results were analyzed to investigate what caused the upwelling and sustained it for a long time. The upwelling was induced by upwelling-favorable wind in July. Coastal upwelling resulted in dynamic uplift of bottom cold water due to geostrophic adjustment. The dynamic uplift decreased sea level in the coastal region. The sea level difference between coastal and offshore regions resulted in an intensified cross-shore pressure gradient which induced geostrophic current accompanied by geostrophic adjustment along the coast. This positive feedback between dynamic uplift and geostrophic adjustment sustained the coastal upwelling for a long time regardless of upwelling-favorable wind.</p>

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Spatial Distribution of Sound Scattering Layer and Density Estimation of Euphausia pacifica in the Center of the Yellow Sea Bottom Cold Water Determined by Hydroacoustic Surveying

Journal of Marine Science and Engineering ◽

10.3390/jmse10010056 ◽

2022 ◽

Vol 10 (1) ◽

pp. 56

Author(s):

Hansoo Kim ◽

Garam Kim ◽

Mira Kim ◽

Donhyug Kang

Keyword(s):

Spatial Distribution ◽

Water Temperature ◽

Yellow Sea ◽

Cold Water ◽

Marine Ecosystem ◽

The Yellow Sea ◽

Scattering Layer ◽

Sea Bottom ◽

Sound Scattering Layer ◽

Bottom Cold Water

The Yellow Sea Bottom Cold Water (YSBCW) refers to seawater with a water temperature of 10 °C or less found at the bottom of the center of the Yellow Sea. The spatiotemporal variability of the YSBCW directly affects the distribution of organisms in the marine ecosystem. In this study, hydroacoustic and net surveys were conducted in April (spring) to understand the spatial distribution of the sound scattering layer (SSL) and estimate the density of Euphausia pacifica (E. pacifica) in the YSBCW. Despite the shallow water in the YSBCW region, E. pacifica formed an SSL, which was distributed near the bottom during the daytime; it showed a diel vertical migration (DVM) pattern of movement toward the surface during the nighttime. The mean upward and downward swimming speeds around sunset and sunrise were approximately 0.6 and 0.3–0.4 m/min, respectively. The E. pacifica density was estimated in the central, western, and eastern regions; the results were approximately 15.8, 1.3, and 10.3 g/m2, respectively, indicating significant differences according to region. The results revealed high-density distributions in the central and eastern regions related to the water temperature structure, which differs regionally in the YSBCW area. Additional studies are needed regarding the spatial distribution of E. pacifica in the YSBCW and its relationship with various ocean environmental parameters according to season. The results of this study contribute to a greater understanding of the structure of the marine ecosystem in the YSBCW.

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Lagged recovery of fish spatial distributions following a cold-water perturbation

Scientific Reports ◽

10.1038/s41598-021-89066-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

M. D. Robertson ◽

J. Gao ◽

P. M. Regular ◽

M. J. Morgan ◽

F. Zhang

Keyword(s):

Water Temperature ◽

Species Distribution ◽

Environmental Conditions ◽

Cold Water ◽

Heat Waves ◽

Rapid Change ◽

Nonlinear Effects ◽

Spatial Distributions ◽

Spatiotemporal Model ◽

Yellowtail Flounder

AbstractAnomalous local temperature and extreme events (e.g. heat-waves) can cause rapid change and gradual recovery of local environmental conditions. However, few studies have tested whether species distribution can recover following returning environmental conditions. Here, we tested for change and recovery of the spatial distributions of two flatfish populations, American plaice (Hippoglossoides platessoides) and yellowtail flounder (Limanda ferruginea), in response to consecutive decreasing and increasing water temperature on the Grand Bank off Newfoundland, Canada from 1985 to 2018. Using a Vector Autoregressive Spatiotemporal model, we found the distributions of both species shifted southwards following a period when anomalous cold water covered the northern sections of the Grand Bank. After accounting for density-dependent effects, we observed that yellowtail flounder re-distributed northwards when water temperature returned and exceeded levels recorded before the cold period, while the spatial distribution of American plaice has not recovered. Our study demonstrates nonlinear effects of an environmental factor on species distribution, implying the possibility of irreversible (or hard-to-reverse) changes of species distribution following a rapid change and gradual recovery of environmental conditions.

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Influence of Various Factors on Caffeine Content in Coffee Brews

Foods ◽

10.3390/foods10061208 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1208

Author(s):

Ewa Olechno ◽

Anna Puścion-Jakubik ◽

Małgorzata Elżbieta Zujko ◽

Katarzyna Socha

Keyword(s):

Literature Review ◽

Water Temperature ◽

Geographical Origin ◽

Cold Water ◽

Water Type ◽

Robusta Coffee ◽

Caffeine Content ◽

Type Water ◽

Brewing Time ◽

Coffee Brews

Coffee brews are one of the most popular drinks. They are consumed for caffeine and its stimulant properties. The study aimed to summarize data on the influence of various factors on caffeine content in brews prepared with different methods. The study was carried out using a literature review from 2010–2020. PubMed and Google Scholar databases were searched. Data on caffeine content was collected by analyzing the following factors: the influence of species, brewing time, water temperature, pressure, degree of roast, grinding degree, water type, water/coffee ratio as well as other factors (such as geographical origin). To sum up, converting caffeine content to 1 L of the brew, the highest content is that of brews prepared in an espresso machine (portafilter), with the amount of 7.5 g of a coffee blend (95% Robusta + 5% Arabica), and water (the volume of coffee brew was 25 mL) at a temperature of 92 °C and a pressure of 7 bar, but the highest content in one portion was detected in a brew of 50 g of Robusta coffee poured with 500 mL of cold water (25 °C) and boiled.

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Combined Effects of Summer Water Temperature and Current Velocity on the Distribution of a Cold-Water-Adapted Sculpin (Cottus nozawae)

Water ◽

10.3390/w13070975 ◽

2021 ◽

Vol 13 (7) ◽

pp. 975

Author(s):

Kaiji Suzuki ◽

Nobuo Ishiyama ◽

Itsuro Koizumi ◽

Futoshi Nakamura

Keyword(s):

Water Temperature ◽

Climate Warming ◽

Current Velocity ◽

Cold Water ◽

Environmental Gradients ◽

Combined Effect ◽

Influential Factor ◽

Combined Effects ◽

River Catchment ◽

Water Abstraction

Clarifying the combined effects of water temperature and other environmental factors on the species distributions of cold-water fishes is the first step toward obtaining a better understanding of the complex impacts of climate warming on these species. In the present study, we examined the abundance and occurrence of the fluvial sculpin, Cottus nozawae, in response to water temperature along environmental gradients in northern Japan. The abundance survey was conducted in the Sorachi River catchment with two-pass electrofishing with a backpack electrofisher. For the occurrence survey, we carried out one-pass electrofishing in the Sorachi, Chitose, and Tokachi River catchments. Fish sampling was conducted once from July to August 2018 in the Sorachi River catchment, from May to June 2011 in the Chitose River catchment, and from July to September 2012 in the Tokachi River catchment. Generalized linear mixed models (GLMMs) and generalized linear models (GLMs) were used for the abundance and occurrence analyses, respectively. We found that the mean summer water temperature was the most influential factor on the distribution of C. nozawae; the abundance and occurrence were both negatively affected by increased water temperatures. In the occurrence model, occurrence probabilities of 0.9 and 0.5 for C. nozawae corresponded to mean summer temperatures of 12.0 and 16.1 °C, respectively. Furthermore, we identified a combined effect of water temperature and current velocity on the abundance of C. nozawae. The increased mean summer water temperature had a stronger negative effect on C. nozawae abundance under gentle flow conditions. While the precise mechanisms of this combined effect could not be determined in this study, stressors associated with low current velocities may increase their vulnerability to higher water temperatures. Our findings indicate that flow disturbances caused by human activities such as excessive water abstraction may exacerbate the negative impacts of climate warming on populations of C. nozawae in the future.

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A strategic sampling design revealed the local genetic structure of cold-water fluvial sculpin: a focus on groundwater-dependent water temperature heterogeneity

Heredity ◽

10.1038/s41437-021-00468-z ◽

2021 ◽

Author(s):

Souta Nakajima ◽

Masanao Sueyoshi ◽

Shun K. Hirota ◽

Nobuo Ishiyama ◽

Ayumi Matsuo ◽

...

Keyword(s):

Genetic Structure ◽

Water Temperature ◽

Sampling Design ◽

Cold Water

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Fluctuating temperature of the mains water throughout the year and its influence on the consumption of energy for the purposes of DHW preparation

E3S Web of Conferences ◽

10.1051/e3sconf/20184400017 ◽

2018 ◽

Vol 44 ◽

pp. 00017 ◽

Cited By ~ 5

Author(s):

Agnieszka Chmielewska

Keyword(s):

Water Treatment ◽

Water Temperature ◽

Cold Water ◽

Treatment Plant ◽

Water Treatment Plant ◽

Monthly Basis ◽

New Model ◽

Water Influence ◽

Family Building ◽

Cold Water Temperature

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.

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Skinfolds and resting heat loss in cold air and water: temperature equivalence

Journal of Applied Physiology ◽

10.1152/jappl.1975.39.1.93 ◽

1975 ◽

Vol 39 (1) ◽

pp. 93-102 ◽

Cited By ~ 40

Author(s):

R. M. Smith ◽

J. M. Hanna

Keyword(s):

Heat Transfer ◽

Water Temperature ◽

Heat Loss ◽

Air Temperature ◽

Indirect Calorimetry ◽

Cold Water ◽

Heat Conductance ◽

Air Temperatures ◽

Body Core ◽

Male Subjects

Fourteen male subjects with unweighted mean skinfolds (MSF) of 10.23 mm underwent several 3-h exposures to cold water and air of similar velocities in order to compare by indirect calorimetry the rate of heat loss in water and air. Measurements of heat loss (excluding the head) at each air temperature (Ta = 25, 20, 10 degrees C) and water temperature (Tw = 29–33 degrees C) were used in a linear approximation of overall heat transfer from body core (Tre) to air or water. We found the lower critical air and water temperatures to fall as a negative linear function of MSF. The slope of these lines was not significantly different in air and water with a mean of minus 0.237 degrees C/mm MSF. Overall heat conductance was 3.34 times greater in water. However, this value was not fixed but varied as an inverse curvilinear function of MSF. Thus, equivalent water-air temperatures also varied as a function of MSF. Between limits of 100–250% of resting heat loss the followingrelationships between MSF and equivalent water-air temperatures were found (see article).

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Numerical Modeling of the Interference of Thermally Unbalanced Aquifer Thermal Energy Storage Systems in Brussels (Belgium)

Energies ◽

10.3390/en14196241 ◽

2021 ◽

Vol 14 (19) ◽

pp. 6241

Author(s):

Manon Bulté ◽

Thierry Duren ◽

Olivier Bouhon ◽

Estelle Petitclerc ◽

Mathieu Agniel ◽

...

Keyword(s):

Energy Storage ◽

Groundwater Flow ◽

Heat Transport ◽

Thermal Energy ◽

Thermal Energy Storage ◽

Cold Water ◽

Cooling System ◽

Joint Operation ◽

Groundwater Temperature ◽

Aquifer Thermal Energy Storage

A numerical model was built using FEFLOW® to simulate groundwater flow and heat transport in a confined aquifer in Brussels where two Aquifer Thermal Energy Storage (ATES) systems were installed. These systems are operating in adjacent buildings and exploit the same aquifer made up of mixed sandy and silty sublayers. The model was calibrated for groundwater flow and partially for heat transport. Several scenarios were considered to determine if the two ATES systems were interfering. The results showed that a significant imbalance between the injection of warm and cold water in the first installed ATES system led to the occurrence of a heat plume spreading more and more over the years. This plume eventually reached the cold wells of the same installation. The temperature, therefore, increased in warm and cold wells and the efficiency of the building’s cooling system decreased. When the second ATES system began to be operational, the simulated results showed that, even if the heat plumes of the two systems had come into contact, the influence of the second system on the first one was negligible during the first two years of joint operation. For a longer modeled period, simulated results pointed out that the joint operation of the two ATES systems was not adapted to balance, in the long term, the quantity of warm and cold water injected in the aquifer. The groundwater temperature would rise inexorably in the warm and cold wells of both systems. The heat plumes would spread more and more over the years at the expense of the efficiency of both systems, especially concerning building’s cooling with stored cold groundwater.

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