• Title/Summary/Keyword: Salinity difference

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Characteristics of Red Tide Blooms in the Lower reaches of Taehwa River (태화강 하류의 적조발생 특성)

  • Cho, Hong-Je;Yoon, Yeong-Bae;Kang, Ho-Seon;Yoon, Sung-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.453-462
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    • 2011
  • This study was analyzed to determine the cause of red tide at 10 and 30 days antecedental rainfall, stage and discharge in the Taehwa River, tidal data of Ulsan port, also, it was analyzed variation of red tide population, salinity, BOD, COD, T-N, T-P at S1, S2 each point. Most of the red tide in the Taehwa River occurred by provision of proper nutrients with antecedent, the proximity between discharge and low-flow capacity, and stage and discharge of stabilized condition after the sea water was inflowed by maximum tide difference. Red tide population is not nearly related to the change of salinity, the Taehwa River seems specific features of Non-coastal rivers downstream, because red tide was occurred when salinity quite low-end condition.

Validation of Satellite SMAP Sea Surface Salinity using Ieodo Ocean Research Station Data (이어도 해양과학기지 자료를 활용한 SMAP 인공위성 염분 검증)

  • Park, Jae-Jin;Park, Kyung-Ae;Kim, Hee-Young;Lee, Eunil;Byun, Do-Seong;Jeong, Kwang-Yeong
    • Journal of the Korean earth science society
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    • v.41 no.5
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    • pp.469-477
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    • 2020
  • Salinity is not only an important variable that determines the density of the ocean but also one of the main parameters representing the global water cycle. Ocean salinity observations have been mainly conducted using ships, Argo floats, and buoys. Since the first satellite salinity was launched in 2009, it is also possible to observe sea surface salinity in the global ocean using satellite salinity data. However, the satellite salinity data contain various errors, it is necessary to validate its accuracy before applying it as research data. In this study, the salinity accuracy between the Soil Moisture Active Passive (SMAP) satellite salinity data and the in-situ salinity data provided by the Ieodo ocean research station was evaluated, and the error characteristics were analyzed from April 2015 to August 2020. As a result, a total of 314 match-up points were produced, and the root mean square error (RMSE) and mean bias of salinity were 1.79 and 0.91 psu, respectively. Overall, the satellite salinity was overestimated compare to the in-situ salinity. Satellite salinity is dependent on various marine environmental factors such as season, sea surface temperature (SST), and wind speed. In summer, the difference between the satellite salinity and the in-situ salinity was less than 0.18 psu. This means that the accuracy of satellite salinity increases at high SST rather than at low SST. This accuracy was affected by the sensitivity of the sensor. Likewise, the error was reduced at wind speeds greater than 5 m s-1. This study suggests that satellite-derived salinity data should be used in coastal areas for limited use by checking if they are suitable for specific research purposes.

Diffusion Analysis of the High Temperature and Salinity Water by the 3-D Baroclinic Flow Model (3-D 밀도류모델을 이용한 고온${\cdot}$고염수의 확산해석)

  • Kim, Jong-In;Kim, Hyeon-Ju
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3B
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    • pp.3-13
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    • 1999
  • The diffusion characteristics of the high temperature and salinity water discharged in Chinhae Bay under BMP(Barge-Mounted Plants) desalination processes were simulated to access environmental impact. The 3-D baroclinic flow model is formulated by integrating the basic equations with respect to each control volume and by transforming them into a finite difference form using the space-staggered grid system. With a 3-D baroclinic flow model, the tide-induced and density-induced current was computed and confirmed by comparing with observed data. From the results of numerical experiment, it is expected that the maximum diffusion lengths of the high temperature and salinity which increase $0.6^{circ}C$ and 0.2 after discharging are 1 km and 3.5km, respectively. It may be expected that the discharge has an effect on surrounding area of discharge, but not an effect on whole area of Chinhae Bay.

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Microbial population in Han River estuary (한강하류 감조수역에 있어서의 미생물분포)

  • Hong, Soon-Woo;Hah, Yung-Chil;Lee, Kwang-Woong
    • Korean Journal of Microbiology
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    • v.6 no.4
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    • pp.107-112
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    • 1968
  • Examining the microbial populations in the Han River estuary, we conducted this experiment at six sites of the estuarine area, Chollyu-ri, Cholsan-ri, Wolgon-ri, Chogi-ri, Inhwa-ri, and Oepo-ri for 5 months since May 1967. From the results obtained it could be summarized as follows. 1) The salinity of the estuarine water increased in order of the distances from the base point of the Old Han River Bridge to every site of the estuary, and pH of the water, which were between 7. 3 and 8. 1, showing little difference each other in both the sites and dates of experiment. 2) The populations of the general bacteria and coliform group bacteria were highest at the site of Chollyu-ri, and it decreased with the downstreaming of the river water toward Oepo-ri site. As for fungi which have comparatively high tolerance to the salinity, its population was shown hi hest at Chogi-ri. 3) The relationship between the salinity and the number of the general bacteria have indicated that the incresed salinity reduced the growth rates of the bacteria. By this it can be assumed that the fresh-water bacteria decreased due to the sea water as well as its dilution effects. 4) The high pollution of the esturarine water was caused by the increases of inhabitants and water thrown by industries in Seoul and Kyung-In Industrial District as well as the excrements fertilized to the farms.

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Survival Rate and Body Composition Changes in Juvenile Abalone Haliotis discus hannai by Temperature/Salinity Change (급격한 염분변화에 따른 수온별 참전복(Haliotis discus hannai) 치패의 생존율 및 체성분 변화)

  • Jeong, Min Hwan;Kim, Seong-Hee;Park, Mi Seon;Kim, Kang Woong;Chang, Young Jin;Myeong, Jeong-In
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.5
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    • pp.565-570
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    • 2013
  • Physiological studies on the salinity tolerance with respect to survival rate and body composition changes of the abalone Haliotis discus hannai were conducted by rapidly changing the salinity in an indoor rearing system. The survival rate of the control (35 psu), 30 and 25 psu groups at $15^{\circ}C$ was 100%. The survival rate of the 20 psu group was $35{\pm}5.0%$. Survival rate of the 15 psu group was 0%. At $15^{\circ}C$ and 35, 30, 25, 20, 15 psu, the moisture contents of abalone muscle were $82.1{\pm}0.7$, $82.5{\pm}0.7$, $84.9{\pm}0.5$, $86.9{\pm}0.3$ and $86.6{\pm}0.4%$, respectively. Crude lipid contents were $0.47{\pm}0.03$, $0.47{\pm}0.03$, $0.47{\pm}0.09$, $0.77{\pm}0.09$ and $0.63{\pm}0.03%$, respectively and crude ash contents were $1.30{\pm}0.12$, $1.33{\pm}0.15$, $1.13{\pm}0.23$, $1.87{\pm}0.15$ and $1.40{\pm}0.31%$, respectively. At salinity below 20 psu, these values increased compared with the control. The general components of abalone muscles significantly increased below 20 psu, while amino acid composition showed no significant difference with salinity and water temperature.

Saline Water Movement In The Estuary Of The Nakdong River (낙동강 하구의 염수운동)

  • Chang, Sun-duck;Ryu, Cheong-ro;Lee, Mun-ok;Lee, Jae Chul
    • 한국해양학회지
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    • v.16 no.1
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    • pp.31-37
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    • 1981
  • Saline water movements in relation to tidal condition and river discharge in the estuary of the Nakdong River are discussed on the basis of the observation data. The difference of salinity between the surface and the bottom layer was 1∼3 at spring tide forming a vertically homogeneous estuary, while at neap tide, it ranges up to 7∼15 indicating a sharp salt wedge. The maximum salinity appeared approximately at an hour after the high water, that is, three hours after the landward velocity maximum, while the salinity maximum at around an hour after the low water, that is, three hours after the seaward velocity maximum. The density current speed at a section located 10km landward from the river mouth was observed approximately to be 45cm sec$\^$-1/ at 8m layer.The relations between the salinity at Gupo and the river discharge at Jindong are estimated by means of the least square method. The maximum length of the salt wedge is calculated approximately to be 22km at neap tide and 16km at spring tide, which is in accordance with the observed data. The salinity influence area is deduced to be 45km at spring tide and 35km at neap tide. The diffusion coefficient of salinity was estimated approximately to be 1.5 10$\^$8/$\textrm{cm}^2$ sec$\^$-1/ at Samrak and 8 10$\^$5/$\textrm{cm}^2$ sec$\^$-1/ at Gupo at neap tide, while it was 1.4 10$\^$7/$\textrm{cm}^2$ sec$\^$-1/ at Dongwon at spring tide.

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Delayed Mode Quality Control of Argo Data and Its Verification in the Pacific Ocean (태평양 Argo 자료의 지연모드 품질관리 및 검증연구)

  • Yang, Joon-Yong;Kang, Seong-Yun;Go, Woo-Jin;Suh, Young-Sang;Seo, Jang-Won;Suk, Moon-Sik
    • Journal of Environmental Science International
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    • v.17 no.12
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    • pp.1353-1361
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    • 2008
  • Quality control of Argo(Array for Real-time Geostrophic Oceanography) data is crucial by reason that salinity measurements are liable to experience some drift and offset due to biofouling, contamination of sensor and wash-out of biocide. The automated Argo real-time quality control has a limit of sorting data quality, so that WJO program is adopted as standardized method of Argo delayed mode quality control (DMQc) in the world that is a precise quality control method. We conducted DMQC on pressure, temperature and salinity measured by Argo floats in the Pacific Ocean including expert evaluation. Particularly, salinity data were corrected using WJO program. 4 salinity profiles of Argo delayed mode were compared with nearby in situ CTD data and other Argo data in deep layer where oceanographic conditions are stable in time and space. The differences of both salinities were lower than target accuracy of Argo. As compared with the difference of salinities before DMQC, those after DMQC decreased by 60-80 percent. Quality of delayed mode salinity data seemed to be improved correcting salinity data suggested by WJO program.

Quality Characteristics of Low Salt, Low Sodium Oiji (Traditional Korean Cucumber Pickles) by the Addition of Sea Tangle Powder (다시마 분말 첨가에 따른 저염 및 저나트륨 오이지의 품질특성)

  • Kim, Gumjung;Yang, Jiwon;Lee, Kyunghee
    • Journal of the Korean Society of Food Culture
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    • v.34 no.4
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    • pp.440-448
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    • 2019
  • In order to study low salinity Oiji (cucumber pickled in salt) with a reduced content of sodium, which was accomplished by replacing the salt in this saliferous food, we produced Oiji using sea tangle and, then performed physicochemical and sensory evaluations. It was found that the moisture content of Oiji was decreased with increasing the amount of added sea tangle. The pH and acidity were significantly different between the samples made with sea tangle, and the pH and acidity showed no consistent tendency according to the amount of sea tangle powder added. The salinity of Oiji was the highest in the control Oiji (2.92%), and the higher the amount of sea tangle added, the lower was the salinity in the Oiji with the salt replaced by sea tangle (2.78 to 2.89%). The sodium content of Oiji was also the highest in the control Oiji (591.65 mg/100 g) and significantly decreased with the increasing addition of sea tangle (560.43~366.71 mg/100 g). The color value of Oiji showed a significant difference between the samples, with no consistent tendency according to the amount of added sea tangle powder. The hardness of Oiji was significantly greater in the Oiji with the salt replaced by 40% of sea tangle, with greater hardness noted as the amount of added sea tangle powder increased (217.70 g). As a result of the acceptance test of Oiji, there were significant differences between the samples in overall acceptance, appearance, and taste, showing that the Oiji with salt replaced by 30% of sea tangle was significantly highest in overall acceptance and taste. The attribute difference test showed a significant difference only for the brown color, while no significant differences were found between the samples for off-flavor, bitter taste, fermented taste, salty taste, sour taste, hardness and crispness. The above results demonstrated that when sea tangle was substituted for 30 to 40% of the salt content, the Oiji with a low content of sodium and low salinity can be produced with a high level of taste and overall preference. Therefore, this study firmly demonstrated that 30 to 40% of the salt can be replaced by sea tangle as a substitute in order to produce Oiji that has low salinity, a low sodium content.

Salinity and water level measuring device using fixed type buoyancy (고정식 부력을 이용한 염도 및 수위 측정 방식에 대한 연구)

  • Yang, Seung-Young;Byun, Kyung-Seok
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.1
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    • pp.1-6
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    • 2020
  • To make an automated system for a salt field, it is necessary to measure the salinity and water level of the evaporation site. In this paper, a method to simultaneously measure the salinity and water level by measuring the buoyancy forces of two fixed buoyancy bodies is proposed. The proposed measurement method measures the buoyancy of the main part and reference part when the measuring device is immersed in the salty water, and simultaneously measures the salinity and water level through the sum and difference of the two buoyancy forces. Since there is no mechanical movement in the measurement of buoyancy, measurement errors and maintenance needs can be reduced in the mudy environment of salt field. By applying the proposed method, we developed a system that can simultaneously measure salinity and water level remotely at the evaporation site of a salt field. Through a measurement experiment using a reference salty water having various levels of salinity, the results of a salinity error of 0% and a water level error of 2mm were obtained, and the effectiveness of the proposed salinity and water level measuring device was verified. When an automated system is constructed using the developed salinity and water level measuring device, labor reduction, work environment improvement, and productivity improvement are expected.

Survival on Water Temperature, Salinity and Air Exposed Time and Sand Immersion Ability of the Surf Clam, Spisula sachalinensis Spat (북방대합 치패의 수온, 염분 및 공기노출에 따른 생존율과 잠사능력)

  • 이정용;김완기;이채성;박영제
    • Journal of Aquaculture
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    • v.16 no.4
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    • pp.229-232
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    • 2003
  • Survival with various conditions (water temperature, salinity and air exposure) and sand immersion ability for release of surf clam, Spisula sachalinensis spats, which were artificially seed produced, were investigated. Survival with water temperature conditions of spats showed no difference within the range of 4∼28 $^{\circ}C$ for 10 days. In salinity conditions, survival (%) of spats showed more than 50% in over 22 psu. In air exposure conditions, survival (%) of spats air exposed for 12 hours was no difference within below 2$0^{\circ}C$, however, that of spats air exposed for 16 hours showed below 50% at $25^{\circ}C$. In sand immersion ability, the immersion time was increased with the increase of shell length, and the immersion rate was decreased. Spats of below 15 mm in shell length were emersed more than 90% within 10 min. There was no difference in the immersion time and the immersion rate with the grain sizes of the sand bottom.