• Title, Summary, Keyword: 수온

Search Result 2,759, Processing Time 0.044 seconds

Seasonal Variation of Surface Temperatures in the Neighbouring Seas of Korea (韓國周邊 海洋表面水溫의 季節的 變化)

  • Kang, Yong Q;Jin, Myoung-Shin
    • 한국해양학회지
    • /
    • v.19 no.1
    • /
    • pp.31-35
    • /
    • 1984
  • The seasonal variation of sea surface temperatures (SST) in the neighbouring seas of Korea was studied performing the harmonic analysis of the monthly mean SST data of 15 years (1961-1975) at 182 stations routinely collected by the Fisheries Research and Development Agency. The mean SST in the West Sea (Yellow Sea) is lower than that in the East Sea (Sea of Japan) whereas the annual range of SST in the West Sea is much larger than that in the East Sea. The maximum SST occurs between mid August and early September. The seasonal variation of SST in the seas of Korea is influenced by incoming radiation and heat advections by ocean currents and winds.

  • PDF

Study on the Retreatment Techniques for NOAA Sea Surface Temperature Imagery (NOAA 수온영상 재처리 기법에 관한 연구)

  • Kim, Sang-Woo;Kang, Yong-Q.;Ahn, Ji-Sook
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.17 no.4
    • /
    • pp.331-337
    • /
    • 2011
  • We described for the production of cloud-free satellite sea surface temperature(SST) data around Northeast Asian using NOAA AVHRR(Advanced Very High Resolution Radiometer) SST data during 1990-2005. As a result of Markov model, it was found that the value of Markov coefficient in the strong current region such as Kuroshio region showed smaller than that in the weak current. The variations of average SST and regional difference of seasonal day-to-day SST in spring and fall were larger than those in summer and winter. In particular, the distribution of the regional difference appeared large in the vicinity of continental in spring and fall. The difference of seasonal day-to-day SST was also small in Kuroshio region and southern part of East Sea due to the heat advection by warm currents.

Correlation and Hysteresis Analysis of Air-Water Temperature in Four Rivers: Preliminary study for water temperature prediction (우리나라 하천의 기온-수온의 상관관계 및 이력현상 분석: 미래 하천수온 변화 예측을 위한 사전검토)

  • An, Ji-Hyuck;Lee, Khil-Ha
    • Journal of Environmental Policy
    • /
    • v.12 no.2
    • /
    • pp.17-32
    • /
    • 2013
  • The potential impact of water temperature on air temperature in response to recent anthropogenic global warming has been noticed. To predict climate, induced change in river aquatic environment, it is necessary to understand the thermal constrains of fish species and the timing of the projected river temperature. As a preliminary study, air-water temperature relationship was analyzed on the basis of the observed data during the time period of 2009-2011 and the number of data corresponds to 873-1083. As a result of analyzing the auto-and cross-correlation coefficient between air-water temperature, high correlation is shown (~0.9). It is also found that the correlation coefficient of air temperature is higher than that of water temperature at the lag time less than approximately 10 days. Observed data was divided into two groups to investigate hysteresis: rising limb and falling limb. For some stations there is strong evidence that hysteresis exist between air-water temperature relationships. Consequently it is recommended that seasonal hysteresis needs to be included in determining an airwater relationship.

  • PDF

Impact of Water Temperature Fluctuation due to Hydropeaking on the Downstream (발전방류로 인한 수온의 변동이 하류하천에 미치는 영향 분석)

  • Choi, Byungwoong;Choi, Sung-Uk
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • /
    • pp.118-122
    • /
    • 2016
  • 하천은 하천에 서식하는 동 식물뿐만 아니라 인간에게 매우 중요한 역할을 하고 있다. 그러나 인간의 활동과 산업화에 의해 많은 인위적인 교란을 받고 있으며, 대표적으로 수자원의 이용/발전에 의해 건설된 댐과 저수지를 예로 들 수 있다. 이러한 댐과 저수지는 하천 상 하류간의 생태학적 단절을 초래하여 생물 서식처에 직접적인 영향을 미치고 있으며, 하류하천에 서식하는 생물들에 대한 영향을 고려하지 않고 건설되는 실정이다. 특히, 발전방류로 인한 급격한 유량의 변화와 온도의 변화는 댐 하류하천의 수생태계에 심각한 영향을 미친다고 알려져 있다. 특히, 댐에서의 온도 차이를 가지는 방류로 인해 국내에서의 운문댐, 보령댐 등 일부 댐에서는 벼 수확량 감소사례가 발생하고 있다. 본 연구에서는 댐 발전방류로 인한 수온의 변동이 하류하천에 미치는 영향을 파악하였다. 발전방류로 인한 하류하천의 수리분석과 수온 변화를 모의하기 위하여 CMS-Flow 모형을 사용하였다. 괴산댐 하류에 위치한 달천의 2.3 km구간을 대상구간으로 하였으며, 달천 상류에 위치한 괴산댐은 빈번하게 발전방류를 발생시키고 있다. 발전방류로 인한 수온의 변동이 하류하천에 미치는 영향을 분석하기 위하여 1년 동안의 발전방류 조건에 대하여 모의를 수행하였다. 봄, 여름, 가을, 겨울 총 4계절로 구분하여 발전방류로 인한 수온의 변동이 미치는 범위를 거리에 따라 분석하였을 때, 봄은 1.73 km, 여름은 1.92 km, 가을은 1.74 km, 겨울은 2.01 km까지 영향을 미치는 것으로 나타났다. 방류되는 수온과 하류하천의 수온 차이가 크게 발생하는 여름과 겨울의 경우가 봄과 가을에 비해 영향을 미치는 범위가 큰 것을 알 수 있었다. 본 연구를 통하여 댐 발전방류로 인한 하류하천의 수온 변화를 분석함으로써, 댐 하류하천에서 서식하는 생물들을 고려한 댐 운용 계획을 수립하는데 중요한 기초자료가 될 것으로 기대된다.

  • PDF

ON THE GENERATION OF TEMPERATURE INVERSIONS IN THE UPPER LAYER OF THE OCEAN (해양 표층 수온 역전의 원인)

  • Kang, Yong Q.
    • 한국해양학회지
    • /
    • v.18 no.1
    • /
    • pp.43-48
    • /
    • 1983
  • Oceanic temperature inversions, with unstable stratifications, are frequently founed in the surface layer of a few tens meters in the Japan Sea and the Yellow Sea in Winter. Mechanisms responsible for the generation of temperature inversions include the followings: (1) The nat heat loss at the sea suface requires an upward transport of heat from the interior of the ocean y convection, and this convection leads to the temperature inversions. (2) The downward propagation of the annual variation of the sea surface timperature, with an exponential decrease of amplitude and a linear change of phase with depth, generates the surface inversion layer in winter. (3) The cold water cdvection by Ekman drift, of which magnitude decreases exponentially with depth, generates temperature inversions for the three possible mechanisms mentioned above.

  • PDF

Temperature inversions observed in April in the eastern Yellow Sea (황해동부에서 4월에 관측 수온역전)

  • LEESANGHO
    • 한국해양학회지
    • /
    • v.27 no.4
    • /
    • pp.259-267
    • /
    • 1992
  • A survey of CTD casting was taken in April 1991 in the eastern Yellow Sea. The vertical structure of water column consists of the upper mixed warm, the mid cold and the lower warm layers devised clearly by a seasonal thermocline and the temperature inversion. A strongest temperature inversion is found in the southern part of the survey area. Where the low-layer water is $3^{\circ}C$ higher than the mid-layer water. The area of the temperature inversion covers about $100{\;}km{\;}{\times}{\;}100{\;}km$ and it is observed 1.5 month later. The temperature and salinity of the low-layer water shows a core structure in vertical sections and the tongue-like distribution extending from the south to the north, implying that the warm and saline water found in the oceanic front south of the survey area in early spring is advocated to the north over 150 km underneath the Yellow Sea cold water.

  • PDF

Effect of Temperature on Catches of Anchovy and Sea Mustard(Undaria pinnatifida) in Southern Part of East Sea of Korea (한국동해남부해역의 수온이 멸치와 미역의 생산량에 미치는 영향)

  • Kim, Seong-Hyeon;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.16 no.2
    • /
    • pp.153-159
    • /
    • 2010
  • This study looked into changes in catches of anchovy and production of sea mustard(Undaria pinnatifida) in Southern part of East Sea in Korea from 1990 to 2007 out of the fishing industry production statistics of Korea from 1969 to 2007, and then examined the relationship between the productions and the sea temperature. The production of sea mustard(Undaria pinnatifida) decreased when the sea surface temperature was high, as it adversely affected its production, while its production increased when the sea surface temperature was low, as this facilitated its growth.

Varietal Differences in Days Required to Leaf Expansion, Leaf Number on Main Culm, and Days to Heading of Rice under Cold Water Flow System (찬물 흘려대기 논의 수온 분포에 따른 벼의 엽 전개 일수 및 주간엽수와 출수일수의 품종간 차이)

  • 윤성호;윤종선;유길림;박창기;정근식
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.36 no.3
    • /
    • pp.214-219
    • /
    • 1991
  • To clarify the relationship between ambient water temperature and heading characteristics of rice (Oryza sativa L.), twelve of varieties rice were grown in a cold tolerance screening field where water temperature was controlled by continuous cold water irrigation system to test the cold tolerance of rice. When cold water was continuously irrigated with 5 cm of water depth, the water had stagnated for about three hours, and the water temperature increased gradually from inlet toward outlet in the experimental plot. The fluctuation of water temperature was well synchronized with that of ambient air temperature, and the water temperature near outlet became higher than the air temperature at the vegetative phase, while became lower at the reproductive phase of rice plant community. The leaf development rates on main culm increased by increased water temperature. The rice varities, Fukuhikari, Sangpungbyeo and YR3486-16-2 were more sensitive than the others in the response of leaf development to water temperature. However, Janack and Milyang 42 were comparatively less sensitive to water temperature in leaf development. Janack and Paro -white rices required longer days to develop one leaf on main culm at reproductive phase than at vegetative phase. Varietal difference in days required to develop one leaf on main culm of rice plant was more distinctive at the reproductive phase when water temperature was relatively lower than at the vegetative phase with relatively higher water temperature condition. No difference was found between the growth phases, vegetative and reproductive, in the response of average leaf developmental rates to water temperature under the similar air temperature condition. The estimated average days required to develop one leaf on main culm decreased by 1.3 day by 1$^{\circ}C$ increase in water temperature. Varietal differences in the total number of leaves on main culm depended upon the water temperature, in which the varieties such as Fukuhikari, Gwangmyeon-gbyeo, China 988, and YR3486-16-2 showed increased one leaf by increased water temperature, while Sobaekbyeo, Paro-white, Sangpungbyeo, Pungsanbyeo, Samgangbyeo, and Milyang 42 were kept at the same leaf number regardless of water temperature. However, the total leaf number on main culm and days to heading of Janack increased by increased water temperature. The other varieties showed the shortened days to heading by the increase in water temperature with noticeable varietal differences regardless of the variation in the total number of leaves on main culm.

  • PDF

Oceanological Characteristics of the Ko-Ri Sea Area. I. Annual Cyclic Changes in Water Temperature, Salinity, pH and Transparency (고리해역의 해양학적 특성 I. 수온, 염분, pH 및 투명도의 년간변화에 관하여)

  • Choe, Sang;Chung Tai Wha
    • 한국해양학회지
    • /
    • v.1
    • /
    • pp.37-48
    • /
    • 1971
  • Observations of water temperature, salinity, pH and transparency of the Ko-ri sea area were made between May 1969 and April 1970. A seasonal thermocline was well defined in August, strongly isolating the warm serface water(19-22$^{\circ}C$) from the cold bottom water (14-17.5$^{\circ}C$) introducing from the open sea. In February the coldest isothermal water (11$^{\circ}C$) occurred. In the warm months(May- September), the salinity patterns show great variations with the coastal run-off During the cold months(December-April) the highest isohaline water (35 ) occurred. Annual ranges of surface and bottom pH values were 7.8-8.4(averaging 8.27) and 7.9-8.4(averaging 8.26), respectively. The transparency was greatest (6.0-7.0m) during winter and spring months and least (1.2-2.5m) during summer months.

  • PDF

Hydroacoustic Investigation on the Distribution and Migration Behavior of Fish (어군탐지기에 의한 어군의 분포와 생태계측에 관한 연구)

  • 이대재
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.28 no.4
    • /
    • pp.337-346
    • /
    • 1992
  • Hydroacoustic surveys were conducted in the East China Sea, in the summers of 1990-1991 to investigate the distribution and migration behavior of fish, such as the diel changes in the distributions of fish, the thermoselection behavior of fish, and the fish reactions to a surveying vessel. The hydroacoustic observations were taken with a scientific echo sounder operating at 50kHz and a microcomputer-based echo processor. Fish samples were collected by bottom trawling and temperature was measured with a DBT system. The patterns of fish distributions were compared with the vertical profiles of water temperature. The results obtained can be summarized as follows: 1. The time series of hydroacoustic observations on the downward migration at dawn in the central region of East China Sea showed that the migration rate was 0.24 m/min. In this region, most of the fish collected by bottom trawling during the surveys were squid (Photologio edulis f. budo) and horse mackeral (Trachurus japonicus). 2. The hydroacoustic observations, which together associated with temperature data, indicated that squid and horse mackeral concentrated nocturally in a narrow vertical band of thermocline, particularly in summer when the survey region was strongly stratified. This result suggest that the nocturnal vertical distribution of these species evidently is controlled by temperature. 3. When the survey vessel, that is running at a speed of 11 knots, has suddenly stopped, the fish which concentrated beneath the transducer showed a strong avoidance reaction in the form of rapid downward migration. After a few minutes, the descending reaction disappeared and the fish slowly began the upward migration toward their original swimming positions. Trawl data suggest that the fish, which showed the avoidance reaction, was Liparis tessellatus.

  • PDF