scholarly journals Continuous Measurement of Vertical Water Temperature Profile in the North Basin of Lake Biwa.

1997 ◽  
Vol 58 (3) ◽  
pp. 305-316
Author(s):  
Yuichi HAYAMI ◽  
Tateki FUJIWARA ◽  
Wataru SAKAMOTO
Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4741
Author(s):  
María Gasque ◽  
Federico Ibáñez ◽  
Pablo González-Altozano

This paper demonstrates that it is possible to characterize the water temperature profile and its temporal trend in a hot water storage tank during the thermal charge process, using a minimum number of thermocouples (TC), with minor differences compared to experimental data. Four experimental tests (two types of inlet and two water flow rates) were conducted in a 950 L capacity tank. For each experimental test (with 12 TC), four models were developed using a decreasing number of TC (7, 4, 3 and 2, respectively). The results of the estimation of water temperature obtained with each of the four models were compared with those of a fifth model performed with 12 TC. All models were tested for constant inlet temperature. Very acceptable results were achieved (RMSE between 0.2065 °C and 0.8706 °C in models with 3 TC). The models were also useful to estimate the water temperature profile and the evolution of thermocline thickness even with only 3 TC (RMSE between 0.00247 °C and 0.00292 °C). A comparison with a CFD model was carried out to complete the study with very small differences between both approaches when applied to the estimation of the instantaneous temperature profile. The proposed methodology has proven to be very effective in estimating several of the temperature-based indices commonly employed to evaluate thermal stratification in water storage tanks, with only two or three experimental temperature data measurements. It can also be used as a complementary tool to other techniques such as the validation of numerical simulations or in cases where only a few experimental temperature values are available.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michio Kumagai ◽  
Richard D. Robarts ◽  
Yasuaki Aota

AbstractAn autonomous underwater vehicle (AUV) was deployed in Lake Biwa from 2000 to 2012. In December 2009, ebullition of turbid water was first found in the deepest area (> 90 m) of the North Basin. Follow-up investigations in April and December 2010 and January 2012 confirmed the existence of benthic vents similar to the vents observed in other deep lakes. Importantly, vent numbers per unit travel distance in Lake Biwa dramatically increased from only two vents (0.37 vents km−1) in December 2009 to 54 vents (5.28 vents km−1) in January 2012, which could be related to recent tectonic activity in Japan, e.g., the M9.1 Tohoku earthquake in March 2011 and slow earthquakes along the Nankai Trough from 2006 to 2018. Continuous back-up investigations from 2014 to 2019 revealed additional benthic vents in the same area. The sudden increase in benthic vent activity (liquid and gaseous ebullitions) have significant potential to alter lake biogeochemistry and, ultimately, degrade Japan’s major drinking water source and may be a harbinger of major crustal change in the near future.


2006 ◽  
Vol 29 (4) ◽  
pp. 1913-1920 ◽  
Author(s):  
Osamu Mitamura ◽  
Hiroto Maeda ◽  
Yasushi Seike ◽  
Kunio Kondo ◽  
Naoshige Goto ◽  
...  

2018 ◽  
Vol 70 (1) ◽  
pp. 1-7
Author(s):  
Sergey Golosov ◽  
Ilia Zverev ◽  
Ekaterina Shipunova ◽  
Arkady Terzhevik

Author(s):  
D. H. Cushing ◽  
T. Vucetic

The purpose of this paper is to assess the grazing capacity of Calanus finmar-chicus (Gunner.) in terms of the quantity of food eaten in the sea. The part played in the growth of the animal by the quantity eaten will only be briefly discussed. The parts played by nutrient lack, sinking and diffusion on the algal productive rates will also be discussed, leading to the conclusion that grazing mortality is the most effective controlling agent on algal production.A subsidiary purpose of this paper is to relate changes in the weight of Calanus finmarchicus to changes in food consumed and to changes in water temperature. Measurements of C. finmarchicus have been made by a number of workers (Adler & Jespersen, 1920; Russell, 1928; Marshall, 1933; Stormer, 1929; Bogorov, 1934; Jespersen, 1939; Clarke & Zinn, 1937). It will be shown that in the North Sea, in spring, the greatest changes in weight are most readily related to changes in quantities of food consumed.


1994 ◽  
Vol 112 (2) ◽  
pp. 285-290 ◽  
Author(s):  
J. Veenstra ◽  
P. J. G. M. Rietra ◽  
J. M. Coster ◽  
E. Slaats ◽  
S. Dirks-Go

SUMMARYThe seasonal variation in the occurrence ofV. vulnificusin relation to water temperature and salinity was studied along the Dutch coast. In two consecutive yearsV. vulnificusstrains could be isolated in August when the water temperature was highest. The indole-positive strains isolated from North Sea water samples were identical to most strains isolated from human disease and from the environment. However, strains isolated from four of five patients living in countries around the North Sea were different from the North Sea isolates in that they were indole-negative and have a lower NaCl tolerance.


2013 ◽  
Vol 70 (5) ◽  
pp. 1013-1022 ◽  
Author(s):  
Nan-Jay Su ◽  
Chi-Lu Sun ◽  
André E. Punt ◽  
Su-Zan Yeh ◽  
Gerard DiNardo ◽  
...  

Abstract Su, N.-J., Sun, C.-L., Punt, A. E., Yeh, S.-Z., DiNardo, G., and Chang, Y.-J. 2013. An ensemble analysis to predict future habitats of striped marlin (Kajikia audax) in the North Pacific Ocean. – ICES Journal of Marine Science, 70: 1013–1022. Striped marlin is a highly migratory species distributed throughout the North Pacific Ocean, which shows considerable variation in spatial distribution as a consequence of habitat preference. This species may therefore shift its range in response to future changes in the marine environment driven by climate change. It is important to understand the factors determining the distribution of striped marlin and the influence of climate change on these factors, to develop effective fisheries management policies given the economic importance of the species and the impact of fishing. We examined the spatial patterns and habitat preferences of striped marlin using generalized additive models fitted to data from longline fisheries. Future distributions were predicted using an ensemble analysis, which represents the uncertainty due to several global climate models and greenhouse gas emission scenarios. The increase in water temperature driven by climate change is predicted to lead to a northward displacement of striped marlin in the North Pacific Ocean. Use of a simple predictor of water temperature to describe future distribution, as in several previous studies, may not be robust, which emphasizes that variables other than sea surface temperatures from bioclimatic models are needed to understand future changes in the distribution of large pelagic species.


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