• Journal of the korean society of oceanography
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• 제37권1호
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• pp.20-26
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• 2002

The offshore extension of the East Korean Warm Current (EKWC) mostly turns anti-cyclonically around the Ulleung Warm Eddy (UWE). This fact needs to be dynamically explained because a rectilinear stream past a circular cylinder is normally expected to have a flow pattern symmetric about the stream axis. For this purpose, a simple analytical model is presented in this paper. This model shows that the EKWC's tendency to be anti-cyclonic around the UWE is due to the anti cyclonic circulation generated around the UWE. This tendency results from the geostrophic adjustment between the UWE and the ambient EKWC water. As the strength of the UWE decreases, relative to the EKWC, this model shows that the flow pattern gradually changes from circular to rectilinear.

• 한국해양학회지
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• 제30권3호
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• pp.170-183
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• 1995

1992년 11월부터 1993년 9월 사이 동해남서해역에서 조사한 인공위성 추적부 이, CTD, ADCP 자료를 이용하여 와류와 표층해류의 물리적 구조를 분석하였다. 부이의 이동궤적으로부터 울릉분지내에서 동한난류의 사행과 연구해역에서 다양한 크기의 시계방향과 반시계방향의 와류가 존재하는 것을 처음으로 직접 해류조사로 밝힐 수 있었다. 비교적 오래 지속되는 시계방향의 와류가 울릉분지내와 북부(일 본)분지의 남서쪽에서 관측된 반면에 반시계방향의 와류가 속초와 동해시 사이의 연안역에서 여름철에 관측되었다. 울릉분지의 와류는 적어도 관측기간 중에는 분지 내에 머물러 있었으며, 반시계방향의 와류는 냉수의 존재와 밀접한 관련이 있는 것 으로 나타났다. 북부분지의 시계방향 와류는 울릉분지의 것보다 크며 더 길쭉한 타원 형태를 지녔다. 울릉분지의 와류는 주축과 종축이 각각 120 km, 70 km이고, 회전주기는 13.6일, 평균회전속도는 24 cm/s, 평균 와동운동에너지는 392 $cm^{2}$/s$^{2}$ 이다. 북부분지의 와류는 주축과 종축이 각각 168 km, 86 km이고, 회전 주기는 14.9일, 평균회전속도는 29 cm/s, 평균 와동운동에너지는 629 $cm^{2}$/s/ sup 2/ 의 특성을 보였다. 와류의 평균이동속도는 두 경우 모두 약 3 cm/s이다. 울릉분지내에서 ADCP로 관측한 표층해류와 지형류의 상호일치는 울릉분지의 와류 가 지형평형을 이루고 있음을 시사한다. 관측된 와류는 해저지형에 강하게 지배 되어 있다.

• 한국해양학회지
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• 제11권2호
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• pp.77-88
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• 1976

The water movements in the south sea of Korea are deduced from the distributions of water properties. In summer the flow path of the Tsushima Current is deflected off from the Korean coast; between the coast and the current there exist eddies. Cyclonic eddies are particularly dominant in the southeastern area of Sorido Is. In winter, the sunken coastal water flows out along the bottom toward the southeast, and compensation is made at the surface by the coastward intrusion of off-shore waters. The so-called coastal counter- current of the area seems to be a cyclonic eddy which prevails in summer and autumn.

• 한국수산과학회지
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• 제41권6호
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• pp.518-524
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• 2008

A three-dimensional primitive equation model (POM) and the buoy data (2900 N, 13500 E) from the Japan Meteorological Agency (JMA) for 27 typhoons between 1982 and 2000 are used to investigate the sea surface cooling (SSC) that accompanies typhoons in the northwestern Pacific. Observed sea surface temperatures (SSTs) rapidly drop 0.6 to 4.3 C, and SSC continues for several weeks after the passage of a typhoon. The model, which covers most of the northwestern Pacific ($24^{\circ}N$ to $52^{\circ}N$), simulated Typhoon Abby over the tropical Pacific, and successfully reproduces many observed features, including the pattern of SST decrease, inertial oscillations, etc. The model accurately simulated the SSC process, suggesting that the cyclonic eddy with a radius of a few hundred kilometers that trailed Typhoon Abby plays an important role in SSC.

• 수산해양기술연구
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• 제13권1호
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• pp.1-5
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• 1977

A series of echo-sounding and current measurements as well as the drogue and the drift bottle experiments were carried out in Asan Bay since November 1974. Several sand bars or sand flats covered by silts were developed at ebb tide in the bay. Sand waves and sand ripples were seen on the surface of the sand bars, around which sea channels of 8~ 12 meters in depth are formed. The main stream axis of the flood current which is separated into east and west branch flows southward. A cyclonic and an anticyclonic eddy are developed at the early stage of flood tide. They are transformed into a clockwise eddy before the slack water. The maximum tidal current speed observed was 3.1 ~ 3.2 knots at the entrance of the bay, while it was 1.O ~ 2.8 knots in the bay. The location of the main stream axis of the tidal current coincides well with the sea channel. A salt wedge was observed at the estuary of the Sabgyo-cheon River.

• Journal of the korean society of oceanography
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• 제39권1호
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• pp.96-106
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• 2004

A total of 116 surface sediment samples were obtained on the Yellow Sea and analyzed for grain size and geochemical elements in order to interpret the present sediment transportation. Thirty-nine cores and 3,070 line-km shallow seismic profiles are analyzed for sedimentary records of Yellow Sea in the past. Results show that the boundary of sediment transport between Korean side and Chinese side is about between $123^{\circ}E$ and $124^{\circ}E$. The similar result is produced from Shi et al. (in this publication). Two cyclonic patterns of surface sediments are recognized in the northeastern and southwestern Yellow Sea, while the strong front zone of the mud patch and sandy sediments are found in the southeastern Yellow Sea (the southwestern part of Korean coasts). The formation of fine-particle sediment packages, called for Northwest Mudbelt Deposit (NWMD), Hucksan Mudbelt Deposit (HSMD) and Jeju Mudbelt Deposit (JJMD), are resulted from eddies (gyres) of water circulations in the Yellow Sea. NWMD has been formed by cyclonic (anticlockwise) eddy. NWMD is composed of thick, homogeneous, relatively semi-consolidated gray clay-dominated deposit. On the other hand, HSMD and JJMD are formed by anticyclonic (clockwise) eddies. They are thick, homogeneous, organic-rich gray, silt-dominated deposit. Both core and surface sediments show that the middle zone across Chinese and Korean side contains bimodal frequency of grain-size distribution, indicating that two different transport mechanisms exist. These mud packages are surrounded by sand deposits from both Korea and China seas, indicating that Yellow Sea, which is the shallow sea and epicontinental shelf, is formed mostly by sand deposits including relict sands. The seismic profiles show such as small erosional/non-depositional channels, sand-ridges and sand-waves, Pleistocene-channelfilled deposits, a series of channels in the N-S major channel system, and thick Holocene sediment package, indicating that more complex sedimentary history exists in the Yellow Sea.

• 대한원격탐사학회지
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• 제16권3호
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• pp.211-220
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• 2000

위성자료를 이용하여 동해북부 원산 연근해역의 재발생 와동류에 대한 형태변동, 유속, 발생기작 등을 연구하였다. 1999년 1월 4일부터 3월 18일까지의 기간에 대한 ARGOS의 표류부이 자료(위치정보 및 수온), NOAA 위성의 AVHRR 자료(표면수온) 그리고 Orbview-2 위성의 SeaWiFS 자료(클로로필 a)를 이용하여 재발생 와동류의 수평공간 규모를 파악하였다. 또한 재발생 와동류의 기작과 변동원인을 규명하고자 속초와 울릉도에서의 풍향, 풍속자료, 묵호-울릉도간 해수면 차 값 및 해저지형과 와동류에 포획되어 있는 표류부이의 시.공간적 위치변동간의 상관정도를 파악하였다. 원산 연안해역에서의 와동류의 72일간 평균유속은 153 km/h (42 cm/sec)로 분석되었다. 이 와동류는 cold core, 시계방향의 회전, 직경 110 km의 수평공간을 가진 재발생 와동류로서 와동류의 중심은 위도 $39^{\circ}N$, 경도 $129^{\circ}E$로 분석되었다.

• 한국환경과학회지
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• 제13권2호
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• pp.135-141
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• 2004

Drift data from 17 Argo profiling floats in the East Sea are used to understand the mean flow and its variability in the upper portion of the East Sea Proper Water (UESPW) (around 800 m). The flow penetrates into the Ulleung basin (UB) through two paths: an extension of the southward flowing of the North Korean Cold Water along the east coast of Korea and between Ulleung Island and Dok island. Flows at 800 m are observed in the range of from 0.2 to 4.29 cms-1 and the variability in the north of the UB is larger than that in the south of the UB. In the UB, cyclonic flows from 0.3 to 1.6 cms-1 are observed with the bottom topography. We found that the mean kinetic energy (MKE) and the mean eddy kinetic energy (EKE) are 1.3 and 2.1 cm2s-2 respectively.

• Ocean and Polar Research
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• 제27권2호
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• pp.231-235
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• 2005

The European Iron Fertilization Experiment EIFEX studied the growth and decline of a phytoplankton bloom stimulated by fertilising $10km^2$ in the core of a mesoscale $(80{\times}120km)$ cyclonic eddy south of the Antarctic Polar Front with about 2 times 7 tonnes of iron sulphate. The phytoplankton accumulation induced by iron fertilization did not exceed $3{\mu}g\;chl\;a\;l^{-1}$ despite a draw down of $5{\mu}M$ of nitrate that should have resulted in at least double to triple the amount of phytoplankton biomass assuming regular Redfield-ratios for draw down after phytoplankton growth in the Southern Ocean. During EIFEX the fertilized core of the mesoscale eddy evolved to a hotspot for a variety of small and medium sized mesozooplankton copepods. In contrast to copepods, the biomass of salps (Salpa thompson)) that dominated zooplankton biomass before the onset of our experiment decreased to nearly extinction. Most of the species of the rnosozooplankton community showed extremely hiか feeding rates compared to literature values from Southern Ocean summer communities. At the end of the experiment, massive phytoplankton sedimentation reached the sea floor at about 3800m water depth.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.926-929
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• 2006

Some features of vertical structure of the frontal interaction zone of the warm Kuroshio Current and cold Oyashio Current are known from 1930 from analysis of ship data. Ship data however do not allow carrying out the area detailed survey opposite to satellite infrared (IR) observations which possess by high spatial and temporal resolution. Analysis of NOAA AVHRR IR images demonstrated that process of formation and development of the Kuroshio warm core rings is highly complex. They are formed as a result of development of anticyclonic meanders of the warm Kuroshio waters and spin off them from the current. Joint analysis of thermal infrared images and altimetry data has also indicated that interaction of eddies to the frontal zone plays a crucial role in formation of large eddies moving to the Southern Kuril region.