• Title, Summary, Keyword: Cold water mass

Search Result 176, Processing Time 0.09 seconds

The Ecosystem of the Southern Coastal Water of the East Sea, Korea II. Primary Productivity in and around Cold Water Mass

  • Han, Myung-Soo;Jang, Dong-Hyuk;Yang, Han-Soeb
    • Journal of the korean society of oceanography
    • /
    • v.33 no.4
    • /
    • pp.196-204
    • /
    • 1998
  • $^{14}$C uptake experiments were carried out in and around the cold water mass in the southern part of the Korean East Sea in August and October 1995 to assess spatial and seasonal variability of primary productivity and its relation to physical and chemical factors. The cold and high saline water mass in the bottom layer extended upward to the surface layer and developed along the eastern coast of Korea in August. Chlorophyll-a concentration was maintained high in the cold water mass through August to October and its maximum concentration was 6.3 ${\mu}$g 1$^{-1}$ at Stn. 209-4 in August. Primary productivity and daily primary productivity ranged from 0.29 to 8.02 mgC m$^{-3}$ hr$^{-1}$ and from 58.3 to 63.1 mgC m$^{-2}$ d$^{-1}$, respectively, throughout the study period. Primary productivity of the cold water mass was higher than that of offshore waters in both summer and autumn seasons. P$_{max}$ and I$_{max}$ of the cold water mass in August were higher than those in October, except Stn. 208-5. These results suggest that high primary productivity in the cold water mass may be established by the upwelled nutrients and light adaptaion to convected phytoplankton due to upwelling of the bottom waters.

  • PDF

Spatio-Temporal Variation of Cold Water Masses along the Eastern Coast of Korea in 2013 and 2014

  • Han, In-Seong;Park, Myung-Hee;Min, Seung-Hwan;Kim, Ju-Yeon
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.22 no.3
    • /
    • pp.286-295
    • /
    • 2016
  • With the results of observations in 2013 and 2014 including ocean buoys, in-situ investigations and wind data, we examined the spatio-temporal variation of cold water masses along the eastern coast of Korea. Usually, a cold water mass first appears along the northern part of the eastern coast from May to July, and then along the southern part of the eastern coast from late June to mid-August. Cold water masses appear 3~5 times a year and remain for 5~20 days in the southwestern part of the East Sea. A distinctive cold water mass appeared usually in mid-July in this area, the surface temperature of which was below $10^{\circ}C$ in some cases. During the appearance of a cold water mass in the southwestern part of the East Sea, the horizontal temperature gradient was large at the surface and a significant low water temperature below $8^{\circ}C$ appeared at the bottom level. This appearance of cold water masses clearly corresponded to southwesterly winds, which generated coastal upwelling.

A Study on the Effect of Cold Water Mass on Observed Air Temperature in Busan (부산지역 기온에 미치는 냉수대의 영향에 대한 연구)

  • Park, Myung-Hee;Lee, Joon-Soo;Ahn, Ji-Suk;Suh, Young-Sang;Han, In-Seong;Kim, Hae-Dong;Bae, Hun-Kyun
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.17 no.3
    • /
    • pp.132-146
    • /
    • 2014
  • The effects of the cold air generated from large cold water mass at the coastal area on observed air temperature in Busan were investigated using AWS(Automatic Weather Station) data at the Busan area operated by Korea Meterological Administration and SST(Sea Surface Temperature) data at the Gijang and Busan area operated by Korean National Fisheries Research Development Institute. First, the temperature difference between the coastal area and the city area was about $1^{\circ}C$ during cold water mass day while it was about $0.5^{\circ}C$ if cold water mass was not appeared. Second, for day time, the temperature at the coastal area was about $1^{\circ}C$ lower than that at the city area during cold water mass day, but the difference was only about $0.4^{\circ}C$ without cold water mass. On the other hand, for night time, the temperature at the coastal area was about $1.2^{\circ}C$ lower than that at the city area during cold water mass day and the difference was about $0.9^{\circ}C$ without cold water mass. As a result, temperature differences at night time were higher than those at day time whether or not cold water mass appeared. The reason for higher temperature at night time might be the urban heat island phenomenon.

On the Cold Water Mass Around the Southeast Coast of Korean Peninsula

  • An, Hui Soo
    • 한국해양학회지
    • /
    • v.9 no.2
    • /
    • pp.10-18
    • /
    • 1974
  • The cold water mass around the southeast coast of the Korean Peninsula is analyzed by using CSK data from 1966 through 1970. It is shown that this water mass flows down from the region offshore of Jukbyun to the area of Youngil Bay along the 100meter contour line of bottom topography. In ordinary summer conditions when the current velocity in the Korea Strait is usually above about 50cm/sec and the wind direction is southwest, the cold water ascends to the surface and makes the surface temperature gradient large, unless disturbed by a tropical cyclon. The bottom water of the Korea Strait is formed by the stratification after the Tsushima intermediate water and the Japan Sea intermediate water have been mixed. In winter the Tsushima intermediate water with high salinity sinks rapidly around the inlet of the Japan Sea and prevents the Japan Sea intemediate water from entering the Korea Strait.

  • PDF

CHARACTERISTICS AND ORIGIN OF THE COLD WATER MASS ALONG THE EAST COAST OF KOREA (한국 동해안에 출현하는 냉수괴의 특성과 기원)

  • Kim, Cheol Ho;Kim, Kuh
    • 한국해양학회지
    • /
    • v.18 no.1
    • /
    • pp.73-83
    • /
    • 1983
  • To serch the origin of the cold water mass along the east coast of Korea its characteristics are inrestigated based upon Cooperative Study of Kuroahio and Fisheries Research and Development Agency data. In the southwestern part of the Japan Sea the North Korean Cold Water sinks at the front and flows southwards on top of the Japan Sea Proper Water. it is found that the sunken North Korean Cold Water il high in the content of dissolved oxygen and less saline compared with the Japan Sea Proper Water. It is highly likely that the cold water mass off the Jugbyeon-Chuksan coast in summer il the North Koreah Cold Water and not upwelled Japan Sea Proper Water. It os shown that the Notth Korean cold Water Flows strongly in summer and its scuthern limit is generally off Chuksan-Janggigab and occasionally off Gampo as observed in 1973.

  • PDF

CHEMICAL OCEANOGRAPHIC ASPECT OF THE COLE WATER MASS IN OFFSHORE OF THE EAST COAST OF KOREA (한국 동해안 냉수괴의 해양화학적 고찰)

  • PARK Chung Kil
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.11 no.2
    • /
    • pp.49-54
    • /
    • 1978
  • The cold water mass appeared in offshore of the east coast of Korea in summer season was studied in aspect of chemical oceanography. Such a typical relationship between phosphate and dissolved oxygen as shown in the upwelling regions could not be found in the east coast except around the Kampo coast, southern part of the east coast. It is possible to isolate the North Korean Cold Water from tile proper water of tile Japan Sea by using $\sigma_t-O_2$ diagram. The origin of the cold water mass in offshore of the east coast of Korea in summer is not mainly due to the development of upwelling of the proper water of the Japan Sea but thesouthwardflolvingoftheNorthKoreanCold Water.

  • PDF

Seasonal Variation of Water Mass Distributions in the Eastern Yellow Sea and the Yellow Sea Warm Current

  • Pang, Ig-Chan;Hyun, Kyung-Hoon
    • Journal of the korean society of oceanography
    • /
    • v.33 no.3
    • /
    • pp.41-52
    • /
    • 1998
  • A seasonal circulation pattern in the eastern Yellow Sea (EYS) is suggested from the water mass analysis and geostrophic calculation using the hydrographic data collected by National Fisheries Research and Development Institute during the years of 1970 to 1990. This research focuses on the presence of inflow of warm (and saline) waters into EYS in summer. EYS is divided into two regions in this paper: the west coast of Korea (WCK) and the central Yellow Sea (CYS). In CYS, waters are linked with warm waters near Cheju Island in winter, but with cold waters from the north in summer (in the lower layer). It is not simple to say about WCK because of the influences of freshwater input and tidal mixing. Nevertheless, water mass analysis reveals that along WCK, waters have the major mixing ratios (40-60%) of warm waters in summer, while the dominant mixing ratios (50-90%) of cold waters in winter. Such a seasonal change of water mass distribution can be explained only by seasonal circulation. In winter, warm waters flow northward into CYS and cold waters flow southward along WCK. In summer, warm waters flow northward along WCK and cold waters flow southward into CYS. This circulation pattern is supported by both statistical analysis and dynamic depth topography. Accordingly, Yellow Sea Warm Current may be defined as the inflow of warm waters to CYS in winter and to WCK in summer.

  • PDF

Water Quality Characteristics Along Mid-western Coastal Area of Korea (한국 서해 중부 연안역의 수질환경 특성)

  • Lim, Dhong-Il;Kang, Mi-Ran;Jang, Pung-Guk;Kim, So-Young;Jung, Hoi-Soo;Kang, Yang-Soon;Kang, Young-Shil
    • Ocean and Polar Research
    • /
    • v.30 no.4
    • /
    • pp.379-399
    • /
    • 2008
  • Spatial-temporal variations in physiochemical water qualities (temperature, salinity, DO, SPM, POC and nutrients) of surface and bottom waters were investigated along the mid-western coastal area (Taean Peninsula to Gomso Bay) of Korea. Spatial distribution patterns of temperature and salinity were mostly controlled by the physical mixing process of freshwater from Geum River and/or Gyunggi Bay with nearby coastal water. A strong tidal front is formed off Taean Peninsula during spring and summer. Seasonal variations in nutrient concentrations, lower in spring and summer and higher in fall and winter, are primarily regulated by magnitude of phytoplankton occurrence rather than freshwater loadings into the bay. Based on seasonal and spatial variability of physicochemical parameters, water quality of the study area can be divided into four water masses; Gyunggi Bay-influenced Water Mass (GBWM), Geum River-influenced Water Mass (GRWM), Yellow Sea Bottom Cold Water Mass (YSBCWM) and Cheonsu Bay Water Mass (CBWM). Water quality of the GBWM (Taean Peninsula coastal area), which has relatively low salinity and high concentrations of nutrients, is strongly controlled by the Gyunggi Bay coastal water, which is under influence of the Han River freshwater. In this water mass, the mixed layer is always developed by strong tidal mixing. As a result, a tidal front is formed along the offshore boundary of the mixed layer. Such tidal fronts probably play an important role in the distribution of phytoplankton communities, SPM and nutrients. The GRWM, with low salinity and high nutrients, especially during the flood summer season, is closely related to physiochemical properties of the Geum River. During the flood season, nutrient-enriched Geum River water mass extends up to 60 km away from the river mouth, potentially causing serious environmental problems such as eutrophication and unusual and/or noxious algal blooms. Offshore (<$30{\sim}40m$ in water depth) of the study area, YSBCWM coupled with a strong thermocline can be identified in spring-summer periods, exhibiting abundant nutrients in association with low temperature and limited biological activity. During spring and summer, a tidal front is formed in a transition zone between the coastal water mass and bottom cold water mass in the Yellow Sea, resulting in intensified upwelling and thereby supplying abundant nutrients to the GBWM and GRWM. Such cold bottom water mass and tidal front formation seems to play an important role in controlling water quality and further regulating physical ecosystem processes along mid-western Korean coastal area.

Water Mass Formation Variability in the Intermediate Layer of the East Sea

  • Min, Hong-Sik;Kim, Cheol-Ho
    • Ocean Science Journal
    • /
    • v.41 no.4
    • /
    • pp.255-260
    • /
    • 2006
  • Long-term variability in the intermediate layer of the eastern Japan Basin has been investigated to understand the variability of water mass formation in the East Sea. The simultaneous decrease of temperature at shallower depths and oxygen increasing at deeper depths in the intermediate layer took place in the late 1960's sand the mid-1980's. Records of winter sea surface temperatures and air temperatures showed that there were cold winters that persisted for several years during those periods. Therefore, it was assumed that a large amount of newly-formed water was supplied to the intermediate layer during those cold winters. Close analysis suggests that the formation of the Upper Portion of Proper Water occurred in the late 1960's and the Central Water in the mid-1980's.

Variation and Structure of the Cold Water Around Ganjeol Point Off the Southeast Coast of Korea (하계 용승현상에 따른 간절곶 주변해역의 냉수역 구조와 변동)

  • Choo, Hyo-Sang
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.22 no.7
    • /
    • pp.836-845
    • /
    • 2016
  • The variation and structure of the cold water mass around Ganjeol Point during the summer of 2011 were studied using data from CTD observations and temperature monitoring buoys deployed at 20 stations off the southeast coast of Korea. There was a $-12^{\circ}C$ surface temperature difference between the cold water mass and normal water during the monitoring period. Variations in the isothermal lines for surface temperature along the coast showed that the seabed topography at Ganjeol Point played an important part in the distribution of water temperature. Cold water appeared when the wind components running parallel to the coast had positive values. The upwelling -response for temperature fluctuations was very sensitive to changes in wind direction. Vertical turbulent mixing due to the seabed topography at Ganjeol Point can reinforce the upwelling of cold bottom water. From wavelet analysis, coherent periods found to be 2-8 days during frequent upwelling events and phase differences for a decrease in water temperature with a SSW wind were 12-36 hours.