• Journal of the korean society of oceanography
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• 제33권4호
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• pp.157-167
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• 1998

The distribution of particulate organic carbon and nitrogen (POC and PON) and chlorophyll a of particulate organic matter was investigated in the southwestern East Sea in August and October 1995. The upwelled 'cold water mass' with temperature less than 14$^{\circ}$C occurred near the Campo coast in August. At most of the onshore stations, concentrations of POC and PON were high in surface water, rapidly decreased with depth down to 30 m and then remained constant. Differences in their concentrations between surface and bottom waters were larger in August than in October. At the offshore stations, POC and PON were higher in surface than in deep waters though the differences in concentration were small. The highest, vertically integrated inventories of POC, PON and phytoplanktonic carbon in the upper mixed waters of the onshore stations occurred in August. The mixed layers at onshore stations showed relatively high percentages of POC, PON and chlorophyll a in total suspended matter, low ratios of POC to chlorophyll a and high inventories of phytoplanktonic carbon, compared with the values at offshore stations. These phenomena were more obvious in August, when cold water mass developed strongly, than in October. These results indicate that primary production plays a significant role for the budget of particulate organic matter in the upwelled cold water mass of the southwestern East Sea.

• 중국학논총
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• 제63호
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• pp.343-362
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• 2019

During the traditional periods when there were exchanges among Korea, China and Japan based on ocean currents or seasonal winds, the southwestern coastal areas including Yeosu held an important position since the route would not have been complete without them. Armed with its advantages including the marine environment, the Yeosu area in the southwestern coast on the Korean Peninsula engage in active maritime exchanges and activities as a base along the sea route since the Neolithic or Bronze Age. It was the same later when Baekje and Gaya had exchanges with China and Japan, when Unified Silla had exchanges with China, and when Goryeo had exchanges with China and Japan. In Joseon, the Yeosu area gained fame as a marine defense base. In short, the Yeosu area in the southwestern coast on the Korean Peninsula during the traditional periods not only engage in active maritime exchanges and activities, but also serve as an important base that could not be left out in the maritime history of East Asia.

• 수산해양기술연구
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• 제47권4호
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• pp.356-368
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• 2011

Species composition of fishes and the recruitment properties of jack mackerel, Trachurus japonicus, in the waters around the Geumo Islands in the mid-South Sea were investigated by using both sides fyke nets every month from February to December 2010. During study period, a total of 30,503 fishes (1,380.4 kg) were collected and classified into 2 classes, 16 orders, 61 families and 121 species. The dominant species was jack mackerel occupying 80.5% of total individuals and 44.4% of total biomass. The fork length range of jack mackerel was 5.5-26.8 cm and individuals about 6 cm was appeared only in the middle and southern area of the Geumo Islands in May. The new recruitment of jack mackerel appeared from May in the waters around the Geumo Islands is probably caused by the warm water intrusion associated with the development of stratification due to the extinction of seasonal coastal cold waters by the increase of solar radiation heat. Furthermore, the jack mackerels less than 6 cm recruiting in the mid-South Sea in spring were considered as mixed ones by individuals spawned in the East China Sea and in the waters around the Jeju Island considering the collected time, migration period and spawning time of them.

• Journal of information and communication convergence engineering
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• 제2권1호
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• pp.58-60
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• 2004

Sea level variations and sea surface circulations in the Korean seas were observed by Topex/Poseidon altimeter data from 1993 through 1997. In sea level variations, the West and South Sea showed relatively high variations with comparison to the East Sea. Then, the northern and southern area in the West Sea showed the range of 20∼30cm and 18∼24cm, and the northern west of Jeju island and the southern west of Tsushima island in the South Sea showed the range of 15∼20cm and 10∼15cm, respectively. High variations in the West Sea were results to the inflow in sea surface of Yellow Sea Warm Current (YSWC) and bottom topography. Sea level variations in the South Sea were due to two branch currents (Jeju Warm Current and East Korea Warm Current) originated from Kuroshio Current (KC). In sea surface circulations, there existed remarkably three eddies circulations in the East Sea that are mainly connected with North Korea Cold Current (NKCC), East Korea Warm Current (EKWC) and Tushima Warm Current (TWC). Their eddies are caused basically to the influence of currents in sea surface circulations; Cyclone (0.03 cm/see) in the Wonsan bay off shore with NKCC, and anticyclone (0.06 cm/see) in the southwestern area of Ulleung island with EKWC, and cyclone (0.01 cm/see) in the northeastern area of Tushima island with TWC, respectively.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.879-881
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• 2003

Sea level variations and sea surface circulations in the Korean seas were observed by Topex/Poseidon altimeter data from 1993 through 1997. In sea level variations, the West and South Sea showed relatively high variations with comparison to the East Sea. Then, the northern and southern area in the West Sea showed the range of 20${\sim}$30cm and 18${\sim}$24cm, and the northern west of Jeju island and the southern west of Tsushima island in the South Sea showed the range of 15${\sim}$20cm and 10${\sim}$15cm, respectively. High variations in the West Sea was results to the inflow in sea surface of Yellow Sea Warm Current (YSWC) and bottom topography. Sea level variations in the South Sea was due to two branch currents(Jeju Warm Current and East Korea Warm Current) originated from Kuroshio Current (KC). In sea surface circulations, there existed remarkably three eddies circulations in the East Sea that are mainly connected with North Korea Cold Current (NKCC), East Korea Warm Current (EKWC) and Tushima Warm Current(TWC). Their eddies are caused basically to the influence of currents in sea surface circulations; Cyclone (0.03 cm/sec) in the Wonsan bay off shore with NKCC, and anticyclone (0.06 cm/sec) in the southwestern area of Ulleung island with EKWC, and cyclone (0.01 cm/sec) in the northeastern area of Tushima island with TWC, respectively.

• 한국해양학회지:바다
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• 제2권1호
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• pp.14-20
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• 1997

동해 남서대륙붕은 부산에서 포항까지 내대륙붕에 니질퇴적물이 띠형태로 형성되어있다. 이 지역은 분급도가 대체적으로 불량한 니질퇴적물로 구성되어있다. 연구지역의 물리적, 지질적 그리고 지형학적인 차이는 아마도 살아있는 유공충의 분포에 영향을 미치리라 생각된다. 동해 남서니질퇴적물의 환경기준선을 설정하기 위하여 총 17개의 정점에서 45종의 살아있는 저서성유공충을 이용하여 검증을 해보았다. 살아있는 저서성유공충의 집괴분석은 5개의 서식지로 구분되었다. 이러한 서식지는 각 서식지의 모든 정점에서 나타나는 종에 의하여 각각이 뚜렷하게 구별되고 있다. 각 서식지를 구성하는 종들은 해류, 수심, 영양염 그리고 해저퇴적물의 특정이 서로 연관되어 형성된 것으로 보인다.

• 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 Science Journal
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• 제41권4호
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• pp.301-313
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• 2006

Abundance and distribution of phytoplankton in seawater at southwestern East/Japan Sea near Gampo were investigated by HPLC analysis of photosynthetic pigments during summer of 1999. Detected photosynthetic pigments were chlorophyll a, b, $c_{1+2}$ (Chl a, Chl b, Chl $c_{1+2}$), fucoxanthin (Fuco), prasinoxanthin (Pras), zeaxanthin (Zea), 19'-butanoyloxyfucoxanthin (But-fuco) and beta-carotene (B-Car). Major carotenoid was fucoxanthin (bacillariophyte) and minor carotenoids were Pras (prasinophyte), Zea (cyanophyte) and But-fuco (chrysophyte). Chl a concentrations were in the range of $0.16-8.3\;{\mu}g/land$ subsurface chlorophyll maxima were observed at 0-10m at inshore and 30-50 m at offshore. Thermocline and nutricline tilted to the offshore direction showed a mild upwelling condition. Results from size-fraction showed that contribution from nano+picoplankton at Chl a maximum layer was increased from 18% at inshore to 69% at offshore on average. The maximum contribution from nano+picoplankton was found as 87% at St. E4. It was noteworthy that contribution from nano+picoplanktonic crysophytes and green algae to total biomass of phytoplankton was significant at offshore. Satellite images of sea surface temperature indicated that an extensive area of the East/Japan Sea showed lower temperature ($<18\;^{\circ}C$) but the enhanced Chi a patch was confined to a narrow coastal region in summer, 1999. Exceptionally high flux of low saline water from the Korea/Tsushima Strait seemed to make upwelling weak in summer of 1999 in the study area. Results of comparisons among Chi a from SeaWiFS, HPLC and fluorometric analysis showed that presence of Chi b cause underestimation of Chi a about 30% by fluorometric analysis but overestimation by satellite data about 30-75% compared to HPLC data.

• 한국수산과학회지
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• 제52권6호
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• pp.685-695
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• 2019

To assess the state of Todarodes pacificus fisheries, we examined changes in major fishing and ecological characteristics by comparing jigging fishery data between high (HCLP, 1996-2000) and low (LCLP, 2013-2017) catch level periods. The peak catch occurred in October during the HCLP compared with December during the LCLP. The average catch per unit effort was higher during the HCLP (1.3 tons/jigging vessel) than LCLP (1.0 ton/jigging vessel). During the HCLP, fishing grounds were highly concentrated in the southwestern East Sea and Yamato bank, whereas during the LCLP, the distribution of grounds extended to the South Sea, West Sea, and northern East Sea (near Russian waters) at a low density. Water temperatures in the main fishing ground in the southwestern East Sea were higher at 0, 50, and 100 m depths during the LCLP than HCLP. Meanwhile, the average mantle length of catches decreased from 23.5 cm during the HCLP to 22.21 cm during the LCLP. The mantle length at 50% maturity also decreased between the two periods from 22.06 (HCLP) to 18.77 cm (LCLP). These findings will help guide future management strategies for T. pacificus.

• Journal of the korean society of oceanography
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• 제31권2호
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• pp.89-96
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• 1996

A comparative study between geostrophic currents and directly measured currents was conducted for the upper layer to 200 m depth by using data from eleven observations of CTD and ADCP between March 1992 and November 1993 in the southwestern part of the East Sea. First-order linear relationship was found between calculated geostrophic currents and measured currents with the correlation coefficient of 0.83. On the average, 68.7% of directly measured current can be explained by geostrophic current obtained by dynamic method. The correlation coeflicients increased with total geostrophic transport, which suggests that geostrophic balance is good in areas of strong current.