• Title/Summary/Keyword: Ryukyu Current

Search Result 5, Processing Time 0.02 seconds

Development of High-Resolution Pacific Ocean Circulation Model

  • You Sung-Hyup;Yoon Jong-Hwan;Seo Jang-Won;Youn Yong-Hoon
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2006.05a
    • /
    • pp.129-132
    • /
    • 2006
  • A Pacific Ocean circulation model based on the RIAM Ocean Model (RIAMOM) with $1/6^{\circ}C\;and\;1/12^{\circ}C$ horizontal resolution successfully reproduced the peculiar circulation structures of the Pacific Ocean. The volume transports of model agree very well with the results of observations in the northwestern Pacific Ocean. Also our model successfully reproduced the observed structures of the northeastward Ryukyu Current with a subsurface core at $500{\sim}600m$. A Possible mechanism for the subsurface current core of the Ryukyu Current is proposed focusing on the blocking effect of the Ryukyu Island Chain.

  • PDF

Kuroshio Observation Program: Towards Real-Time Monitoring the Japanese Coastal Waters

  • Ostrovskii, Alexander;Kaneko, Arata;Stuart-Menteth, Alice;Takeuchi, Kensuke;Yamagata, Toshio;Park, Jae-Hun;Zhu, Xiao Hua;Gohda, Noriaki;Ichikawa, Hiroshi;Ichikawa, Kaoru;Isobe, Atsuhiko;Konda, Masanori;Umatani, Shin-Ichiro
    • Ocean and Polar Research
    • /
    • v.23 no.2
    • /
    • pp.141-160
    • /
    • 2001
  • The challenge of predicting the Japanese coastal ocean motivated Frontier Observational Research System for Global Change (FORSGC) and the Japan Marine Science and Technology Center (JAMSTEC) to start a multiyear observational programme in the upstream Kuroshio in November 2000. This field effort, the Kuroshio Observation Program (KOP), should enable us to determine the barotropic and baroclinic components of the western boundary current system, thus, to better understand interactions of the currents with mesoscale eddies, the Kuroshio instabilities, and path bimodality. We, then, will be able to improve modeling predictability of the mesoscale, seasonal, and inter-annual processes in the midstream Kuroshio near the Japanese main islands by using this knowledge. The KOP is focused on an enhanced regional coverage of the sea surface height variability and the baroclinic structure of the mainstream Kuroshio in the East China Sea, the Ryukyu Current east of the Ryukyu's, and the Kuroshio recirculation. An attractive approach of the KOP is a development of a new data acquisition system via acoustic telemetry of the observational data. The monitoring system will provide observations for assimilation into extensive numerical models of the ocean circulation, targeting the real-time monitoring of the Japanese coastal waters.

  • PDF

Determination and Analysis Sea Surface Topography for Unification Vertical Datum in East-Asia Area (동아시아지역 수직기준 통일을 위한 해면지형 결정 및 분석)

  • Huang, He;Yun, Hong-Sic;Lee, Dong-Ha
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.26 no.3
    • /
    • pp.207-217
    • /
    • 2008
  • The SSTop (Sea Surface Topography) provides an estimate of the large scale structure of the deviations between the geoid height and the mean sea surface in terms of a normalized surface spherical harmonic series. The SSTop is the key information which has been used to determine the shape of earth, geoid, current and tide etc. Also, the SSTop is a basic source for the unification of vertical datums at the different height systems which were established according to the their respective purposes. In order to unify the vertical datum around the East-Asian (E-A) region (covers the area: $20^{\circ}-45^{\circ}N$ and $110^{\circ}-140^{\circ}E$), we estimated the value of SSTop in the E-A region using the predicted values of mean sea surface (from KMSS04) and geoid height (from EGM96 and EIGEN-GL04C) and analyzed to aspect of SSTop at 5 tidal stations (InCheon, JeJu, QingDao, Aburatsubo, KeeLung) with the estimated values of each station previously. The result from this study indicates that the SSTop in the E-A region is relatively stable except for the area around the Japanese and Ryukyu deep, and also shows that the distribution of values of SSTop is ranged from 40 to 60 cm at tidal stations except InCheon station.

A Study on the Sanctuary of the Residence in East China Sea Skirts Area (동중국해권 민가의 성역(聖域)에 관한 연구)

  • Youn, Lily;Onomichi, Kenji
    • Korean Journal of Heritage: History & Science
    • /
    • v.43 no.2
    • /
    • pp.60-81
    • /
    • 2010
  • Jeju Island, in Korea, shows many characteristics that are differentiated from the rest of Korea. Its culture is rooted in mythology which advocates a egalitarian, rather than hierarchical, social structure, the place of women in the home is relatively high, and the formation of buildings, the separation of cooking and heating facilities, and the living format of residential homes is dissimilar. These disparities in culture indicate that Jeju Island's heritage was not formed only from influences from the North, but also from other places as well. To fill in the blanks, residential homes in Jeju Island were compared with those scattered throughout the East China Sea, which connect the southern coastline of the Korean peninsula and Jeju Island. The regions encompassed by the East China Sea, sharing the Kuroshio current and a seasonal wind, can be considered as one cultural region integrating cultural aspects from the continental North and the oceanbound South. The unique characteristics of southern culture as seen in southern residences was examined through an investigation of the sacred places in which gods were considered to dwell. First, the myths of these areas usually concerned with the ocean, and a sterile environment made sustenance impossible without a dual livelihood, usually taking on the forms of half-farming and half-fishing, or half-farming, half-gardening. Although family compositions were strongly matricentric or collateral thanks to southern influence, a patriarchical system like those found in the North were present in the upper classes and in the cities. Therefore, residential spaces were not divided based on age or gender, as in hierarchical societies, but according to family and function. Second, these areas had local belief systems based on animism and ancestor worship, and household deities were closely related to women, agriculture and fire. The deities of the kitchen, the granary and the toilet were mostly female, and the role of priest was often filled by a woman. After Buddhism and Confucianism were introduced from mainland Korea, China and Japan, the sacred areas of the household took on a dual form, integrating the female-focused local rites with male-centered Buddhist and Confucian rites. Third, in accordance with worship of a kitchen deity, a granary deity, and a toilet deity led to these areas of the home being separated into disparate buildings. Eventually, these areas became absorbed into the home as architectural technology was further developed and lifestyles were changed. There was also integration of northern and southern cultures, with rites concerning granary and toilet deities coming from China, and the personality of the kitchen deity being related to the southern sea. In addition, the use of stone in separate kitchens, granaries, and toilets is a distinguishing characteristic of the East China Sea. This research is a part of the results gained from a project funded by the Korea Research Foundation in 2006.

An Understanding the Opening Style of the West Philippine Basin Through Multibeam High-Resolution Bathymetry (고해상도 다중빔음향측심 지형자료 분석을 통한 서필리핀분지의 진화 연구)

  • Hanjin Choe;Hyeonuk Shin
    • Journal of the Korean earth science society
    • /
    • v.44 no.6
    • /
    • pp.643-654
    • /
    • 2023
  • The West Philippine Basin, an oceanic basin half the size of the Philippine Sea Plate, lies in the western part of the plate and south of the Korean Peninsula on the Eurasian Plate. It subducts beneath the Eurasian Plate and the Philippine Islands bordering the Ryukyu Trench and the Philippine Trench with 25-50% of this basin already consumed. However, the history of the opening of the basin's southern region has been a topic of debate. The non-transform discontinuity formed during the seafloor spreading is similar to the transform fault boundaries normally perpendicular to mid-ocean ridge axes; however, it was created irregularly due to ridge propagations caused by variations of mantle convection attributable to magma supply changes. By analyzing high-resolution multi-beam echo-sounding data, we confirmed that the non-transform discontinuity due to the propagating rift evolved in the entire basin and that the abyssal hill strike direction changed from E-W to NNW-SSE from the fossil spreading center. In the early stage of basin extension, the Amami-Sankaku Basin was rotated 90 degrees clockwise from its current orientation, and it bordered the Palau Basin along the Mindanao Fracture Zone. The Amami-Sankaku Basin separated from the Palau Basin while the spreading of the West Philippine Basin began with a counter-clockwise rotation. This indicates that the non-transform discontinuities formed by a sudden change in magma supply due to the drift of the Philippine Sea Plate and simultaneously with the rapid changes in the spreading direction from ENE-WSW to N-S. The Palau Basin was considered to be the sub-south of the West Philippine Basin, but recent studies have shown that it extends into an independent system. Evidence from sediment layers and crustal thickness hints at the possibility of its existence before the West Philippine Basin opened, although its evolution continues to be debated. We performed a combined analysis using high-resolution multi-beam bathymetry and satellite gravity data to uncover new insights into the evolution of the West Philippine Basin. This information illuminates the complex plate interactions and provides a crucial contribution toward understanding the opening history of the basin and the Philippine Sea Plate.