• Title/Summary/Keyword: Tides

Search Result 450, Processing Time 0.027 seconds

Ratio of Mixing Effects due to Wind, Surface Cooling, and Tide on West Coast of Korea in December, 1998

  • Park, Yong-Kyu;Lee, Byung-Gul
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
    • /
    • v.4 no.4
    • /
    • pp.249-253
    • /
    • 2000
  • Data obtained from a cruise from 4~12 December, 1998 was analyzed to estimate the mixing effects of wind, surface cooling, and tide. A band denoting a mixing area with a temperature difference of less than 1$^{\circ}C$ between the sea surface and the bottom extended 40~60 km from the coast into the open sea, following 125$^{\circ}$ 30\` E in longitude. This band was divided into two areas; a well-mixed area close to the coast and a stratified region in the open sea. The mixing effect due to the wind was only 2%, yet the mixing effect due to the tides was about 68%. This indicates that surface cooling and tides were the major factors involved in the mixing mechanism on the west coast during the cooling season.

  • PDF

CHARACTERISTICS OF ATMOSPHERIC WAVES OBSERVED FROM AIRGLOW MEASUREMENTS IN THE NORTHERN HIGH-LATITUDE

  • Won, Yong-In;Lee, Bang-Yong;Kwon, Soon-Chul
    • Journal of Astronomy and Space Sciences
    • /
    • v.21 no.2
    • /
    • pp.101-108
    • /
    • 2004
  • The terrestrial nightglow emission in near infrared region were obtained using a Fourier Transform Spectrometer(FTS) at Esrange, Sweden ($67.90^{\circ}$N, $21.10^{\circ}$E) and the OH(4- 2) bands were used to derive temperature and airglow emission rate of the upper mesosphere. For this study, we analyzed data taken during winter of 2001/2002 and performed spectral analysis to retrieve wave information. From the Lomb-Scargle spectral analysis to the measured temperatures, dominant oscillations at various periods near tidal frequency are found. Most commonly observed waves are 4, 6, and 8 hour oscillations. Because of periods and persistence, the observed oscillations are most likely of tidal origin, i.e. zonally symmetric tides which are known to have their maximum amplitudes at the pole.

Effects of environmental factors on the outbreak of freshwater red tide by peridinium bipes in Soyang reservoir (소양호에서 peridinium bipes에 의한 담수적조 발생에 미치는 환경요인의 영향)

  • 강찬수;김상종
    • Korean Journal of Microbiology
    • /
    • v.29 no.6
    • /
    • pp.361-370
    • /
    • 1991
  • Physical and chemical environmental factors influencing on the outbreak of freshwater red tide by Peridinium bipes (dinoflagellate) in Soyang Reservoir were studied. Red tide occured in the site of inflowing of tributary streams annually, but the extent and severity of red tide varied from year to year. Several environmental factors such as water level, nutrient releasing from sediment, cyst resuspension, and concentrations of $Ca^{2+}$ and $Mg^{2+}$were studiedin relation to development, extent, and duration of red tide. In June of 1989 and 1991, the red tides of Peridinium bipes were very severe, and these red tides coincided with notable and rapid drawdown of lake water in late spring. Nutrient releasing and cyst resuspension by turbulence during drawdown were suggested as main causes of red tide. The quanity of nutrient releasing from sediment and hydrometeorological factors such as run-off and wind may determine the extent and duration of red tide.

  • PDF

An Overview of Marine Renewable Energy (해양 신재생에너지의 고찰)

  • Kim, Young C.
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.25 no.6
    • /
    • pp.433-438
    • /
    • 2013
  • With the prospect of an increasing shortage of energy resources, there has been a growing interest in renewable alternative sources of energy. An increasing effort is being directed towards resolving the problems of extracting energy from the world's oceans, as they represent a vast potential source of renewable energy. This paper summarizes the extraction and conversion techniques of the ocean's energy resources, namely, energy derived from the ocean waves, tides, thermal gradients, and currents. For each energy extraction and conversion technique, case studies are discussed.

Vertical Distribution of Tidal Current in the Korea Strait (대한해협조류의 3차원적 분포)

  • 최병호;방인권;김경환
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.6 no.4
    • /
    • pp.421-438
    • /
    • 1994
  • Vertical distribution of tidal currents in the Korea Strait is computed by a tree-dimensional tidal model. The results are presented in the from of tidal charts (coamplitude and cophase chart) and (tidal ellipses charts for eight tidal constituents (M$_2$, S$_2$, $N_2$, $K_2$, $K_1$, $O_1$, P$_1$, Q$_1$) and of harmonic constants for predictions of tides and tidal currents during specified duration in the region. The computed tides were in general agreement with coastal observations and observation-based tidal charts of Odamaki (1989). Comparison between model computation and current observation by RIAM were also presented.

  • PDF

Interactions between marine bacteria and red tide organisms in Korean waters

  • Seong, Kyeong Ah;Jeong, Hae Jin
    • ALGAE
    • /
    • v.28 no.4
    • /
    • pp.297-305
    • /
    • 2013
  • There is increasing interest in the relationships between marine bacteria and red tide organisms. Some bacteria are known to kill red tide organisms, and may be responsible for accelerating the termination of red tides. Thus, certain algicidal bacteria have been proposed for the control of red tides. Meanwhile, many red tide organisms are known to feed on marine bacteria. The roles of marine bacteria and red tide organisms are therefore reversible. In Korean waters, the killing of red tide organisms by algicidal bacteria, and also the feeding of red tide organisms on marine bacteria have been extensively investigated. The findings of such studies may influence the conventional view of red tide dynamics, and also planktonic food webs. Here, we review the species and concentrations of algicidal bacteria that kill red tide organisms in Korean waters, as well as the ingestion rate and grazing impact of red tide organisms on marine bacteria. Furthermore, we offer an insight into the ecological roles of these 2 components in marine planktonic food webs.

Variations of the Diurnal Tides around Jeju-Do (제주도(濟州島) 주변 일주호(日週湖)의 변화)

  • Lee, Sang Ho;Kim, Kuh
    • 한국해양학회지
    • /
    • v.23 no.2
    • /
    • pp.62-69
    • /
    • 1988
  • Analyzing short-term records of sea level data, we show that the amplitudes of diurnal tides along the southern coast of Jeju-Do are significantly larger than those along its northern coast. The amplitude-phase diagrams of $K_1$ and $O_1$ look very similar to that of $M_2$ shown by Kim and Lee (1986), indicating characteristics of the scattering of long waves by Jeju-Do.

  • PDF

Computation of the Sea Surface Topography over the East China Sea (동지나해의 해면변위산정)

  • 최병호
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.4 no.1
    • /
    • pp.1-12
    • /
    • 1986
  • An attempt to obtain equipotential surface over the East China Sea along the three SEASAT ground tracks are described. Total correction of sea surface heights above the reference ellipsoid provided by SEASAT GDR Altimeter data consists of ocean tides and surges, body tides, sea level pressure inverse barometer effect corrections for the present study. It was shown that three equipotential surface derived from the corrections were qualitatively in agreement with GEM l0B Model and SS3 Mean Sea Surface Model.

  • PDF

Observation and Analysis of Shoreline Changes Using the Remote Unmanned Automatic Camera Monitoring System (원격 무인 자동 영상 관측 시스템을 활용한 해안선 변화 관측 및 분석)

  • 김태림
    • Korean Journal of Remote Sensing
    • /
    • v.19 no.2
    • /
    • pp.99-106
    • /
    • 2003
  • The shoreline changes were observed and analysed using the video image by a remote unmanned automatic camera monitoring system installed at Haeundae beach of Busan City. In order to analyse quantitatively the shoreline changes caused by waves and tides, the image averaging technique and the rectification technique for obliquely acquired image were applied to the video image during the typhoon Bart in September, 1999. The results showed that the camera monitoring system can be used as a very cost effective and efficient tool for monitoring shorelines which change continuously due to waves and tides.

Study of the Tidal Channels Appeared on SAR Images

  • Kim, Tae-Rim;Park, Jong-Jib;Choi, Byoung-Ju
    • Korean Journal of Remote Sensing
    • /
    • v.25 no.6
    • /
    • pp.501-505
    • /
    • 2009
  • Quasi-linear bright features persistently appeared on ENVISAT ASAR images as well as X-SAR images along the tidal channels in Gyung-Gi Bay, Korea during the ebb tides. These features are induced by spatial backscatter variations caused by surface convergence (divergence) through the interaction between tidal currents and bathymetry. In order to validate this mechanism, a numerical tidal model simulation is performed on the realistic bathymetry with the tidal boundary conditions. The tide model reproduces the current convergence zone along the tidal channel during the ebb tides, which exactly coincides with the location of bright line features on SAR images.