scholarly journals Temperature structure and characteristics appearing on SSM/I images of the Cosmonaut Sea, Antarctica

1994 ◽  
Vol 20 ◽  
pp. 298-306 ◽  
Author(s):  
Takatoshi Takizawa ◽  
Kay I. Ohshima ◽  
Ushio Shcki ◽  
Toshiyuki Kawamura ◽  
Hiroyuki Enomoto
Keyword(s):  
Water Temperature ◽  
Deep Water ◽  
Cold Water ◽  
Coastal Region ◽  
Water Area ◽  
Temperature Structure ◽  
Circumpolar Deep Water ◽  
Convergence Line ◽  
Coastal Polynya ◽  
Cosmonaut Sea

Water-temperature structure in the Cosmonaut Sea at 60 68° S, 35 65° E in 1987–92 shows that cold water with a temperature below -1.5°C was present in the coastal region. The Circumpolar Deep Water with a temperature higher than 1.0°C was found below about 150m depth from northeast to northwest of the cold water area. The SSM/I images in 1987–91 indicate that polynya activities were intensive in 1988 and the typical Cosmonaut Polynya was observed; due to weaker activities, the small and sporadic Cosmonaut Polynya formed in 1987, 1989, 1990 and 1991. A coastal polynya was frequently observed every year at about 66° S, 50–60° E. A train of polynyas to the east of Cosmonaut Polynya often appeared. It is considered that the Atmospheric Convergence Line and Antarctic Divergence Region are responsible for polynya activities in the Cosmonaut Sea.

scholarly journals Temperature structure and characteristics appearing on SSM/I images of the Cosmonaut Sea, Antarctica

1994 ◽  
Vol 20 ◽  
pp. 298-306 ◽  
Author(s):  
Takatoshi Takizawa ◽  
Kay I. Ohshima ◽  
Ushio Shcki ◽  
Toshiyuki Kawamura ◽  
Hiroyuki Enomoto
Keyword(s):  
Water Temperature ◽  
Deep Water ◽  
Cold Water ◽  
Coastal Region ◽  
Water Area ◽  
Temperature Structure ◽  
Circumpolar Deep Water ◽  
Convergence Line ◽  
Coastal Polynya ◽  
Cosmonaut Sea

Water-temperature structure in the Cosmonaut Sea at 60 68° S, 35 65° E in 1987–92 shows that cold water with a temperature below -1.5°C was present in the coastal region. The Circumpolar Deep Water with a temperature higher than 1.0°C was found below about 150m depth from northeast to northwest of the cold water area. The SSM/I images in 1987–91 indicate that polynya activities were intensive in 1988 and the typical Cosmonaut Polynya was observed; due to weaker activities, the small and sporadic Cosmonaut Polynya formed in 1987, 1989, 1990 and 1991. A coastal polynya was frequently observed every year at about 66° S, 50–60° E. A train of polynyas to the east of Cosmonaut Polynya often appeared. It is considered that the Atmospheric Convergence Line and Antarctic Divergence Region are responsible for polynya activities in the Cosmonaut Sea.

scholarly journals Deep-mixing and deep-cooling events in Lake Garda: Simulation and mechanisms

2021 ◽  
Vol 80 (2) ◽  
Author(s):  
Bouke Biemond ◽  
Marina Amadori ◽  
Marco Toffolon ◽  
Sebastiano Piccolroaz ◽  
Hans Van Haren ◽  
...  
Keyword(s):  
Water Temperature ◽  
Deep Water ◽  
Cold Water ◽  
Vertical Mixing ◽  
Three Dimensional ◽  
Surface Cooling ◽  
Deep Mixing ◽  
Lake Garda ◽  
Turbulence Production ◽  
Strong Winds

A calibrated three-dimensional numerical model (Delft3D) and in-situ observations are used to study the relation between deep-water temperature and deep mixing in Lake Garda (Italy). A model-observation comparison indicates that the model is able to adequately capture turbulent kinetic energy production in the surface layer and its vertical propagation during unstratified conditions. From the modeling results several processes are identified to affect the deep-water temperature in Lake Garda. The first process is thermocline tilting due to strong and persistent winds, leading to a temporary disappearance of stratification followed by vertical mixing. The second process is turbulent cooling, which acts when vertical temperature gradients are nearly absent over the whole depth and arises as a combination of buoyancy-induced turbulence production due to surface cooling and turbulence production by strong winds. A third process is differential cooling, which causes cold water to move from the shallow parts of the lake to deeper parts along the sloping bottom. Two of these processes (thermocline tilting and turbulent cooling) cause deep-mixing events, while deep-cooling events are mainly caused by turbulent cooling and differential cooling. Detailed observations of turbulence quantities and lake temperature, available at the deepest point of Lake Garda for the year 2018, indicate that differential cooling was responsible for the deep-water cooling at that location. Long-term simulations of deep-water temperature and deep mixing appear to be very sensitive to the applied wind forcing. This sensitivity is one of the main challenges in making projections of future occurrences of episodic deep mixing and deep cooling under climate change.

scholarly journals Deep-mixing and deep-cooling events in Lake Garda: Simulation and Mechanisms

2021 ◽  
Author(s):  
Bouke Biemond ◽  
Marina Amadori ◽  
Marco Toffolon ◽  
Sebastiano Piccolroaz ◽  
Hans van Haren ◽  
...  
Keyword(s):  
Water Temperature ◽  
Deep Water ◽  
Cold Water ◽  
Vertical Mixing ◽  
Three Dimensional ◽  
Surface Cooling ◽  
Deep Mixing ◽  
Lake Garda ◽  
Entire Depth ◽  
Strong Winds

<div> <div> <div> <p>A calibrated three-dimensional numerical model <span>(Delft3D) and in-situ observations are used to study the relation between deep water temperature and mixing in Lake Garda (Italy). A model-observation comparison indicates that the model is able to adequately capture the production of turbulent kinetic energy in the surface layer and its vertical propagation during unstratified conditions. Here, the model is used as a support to identify the main processes causing deep water cooling and deep mixing in the lake. The analysis indicated that two processes cause mixing over the entire depth. The first process is thermocline tilting due to strong and persistent winds. This is found to generate a temporary disappearance of stratification followed by vertical mixing over the entire depth. The second process is turbulent cooling, which arises as a combination of negative-buoyancy produced by surface cooling and turbulence injection from strong winds. Turbulent cooling acts when vertical temperature gradients are absent over the whole depth and cools and mixes the lake over its entire vertical. The third identified process is associated to differential cooling between the shallow southern part and the deep northern trunk. This generates the advection of cold water from the southern, colder and well-mixed basin to the norther trunk along the sloping bottom of the lake. Such differential cooling is found to be a consequence of the turbulent cooling and is not associated with mixing over the entire depth in the northern trunk. Available observations indicate that the three processes identified from the model indeed occur in Lake Garda. Long- term simulations of deep water temperature and related deep mixing appear to be very sensitive to the atmospheric forcing, whose accurate reproduction is essential for the prediction of the future occurrence of deep mixing events.</span></p> </div> </div> </div>

scholarly journals Warm Circumpolar Deep Water transport toward Antarctica driven by local dense water export in canyons

2020 ◽  
Vol 6 (18) ◽  
pp. eaav2516 ◽  
Author(s):  
A. K. Morrison ◽  
A. McC. Hogg ◽  
M. H. England ◽  
P. Spence
Keyword(s):  
Deep Water ◽  
Cold Water ◽  
Ross Sea ◽  
Volume Transport ◽  
Ocean Model ◽  
Ice Shelves ◽  
Circumpolar Deep Water ◽  
Spatially Correlated ◽  
Global Sea Level ◽  
The Relationship

Poleward transport of warm Circumpolar Deep Water (CDW) has been linked to melting of Antarctic ice shelves. However, even the steady-state spatial distribution and mechanisms of CDW transport remain poorly understood. Using a global, eddying ocean model, we explore the relationship between the cross-slope transports of CDW and descending Dense Shelf Water (DSW). We find large spatial variability in CDW heat and volume transport around Antarctica, with substantially enhanced flow where DSW descends in canyons. The CDW and DSW transports are highly spatially correlated within ~20 km and temporally correlated on subdaily time scales. Focusing on the Ross Sea, we show that the relationship is driven by pulses of overflowing DSW lowering sea surface height, leading to net onshore CDW transport. The majority of simulated onshore CDW transport is concentrated in cold-water regions, rather than warm-water regions, with potential implications for ice-ocean interactions and global sea level rise.

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

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℃ 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℃ 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>

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

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.

scholarly journals Influence of Various Factors on Caffeine Content in Coffee Brews

Foods ◽  
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.

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

Water ◽  
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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