This study provides comprehensive assessment results for the most recent high-resolution regional climatology in the East/Japan Sea by comparing with the various existing climatologies. This new high-resolution climatology is generated based on the Optimal Interpolation (OI) method with individual profiles from the World Ocean Database and gridded World Ocean Atlas provided by the National Centers for Environmental Information (NCEI). It was generated from the recent previous study which had a primary focus to solve the abnormal horizontal gradient problem appearing in the other high-resolution climatology version of NCEI. This study showed that this new OI field simulates well the mesoscale features including closed-curve temperature spatial distribution associated with eddy formation. Quantitative spatial variability was compared to the other four different climatologies and significant variability at 160 km was presented through a wavelet spectrum analysis. In addition, the general improvement of the new OI field except for warm bias in the coastal area was confirmed from the comparison with serial observation data provided by the National Fisheries Research and Development Institute’s Korean Oceanic Data Center.
태풍, 집중호우, 대설은 매년 우리나라에서 치명적인 손실을 초래한다. 따라서 정기적인 관측을 통하여 이러한 현상의 발생 가능성을 미리 알 수 있다면, 사회적으로 큰 유익을 제공할 수 있을 것이다. 우리나라는 삼면이 바다로 둘러싸여 있고, 해수면온도가 태풍, 집중호우, 대설 발달에 직·간접적으로 영향을 미치므로, 이 논문에서는 위험기상과 관련하여 나타나는 해수면온도 변동성의 특성을 조사하였다. 우리나라에서 발생하는 집중호우는 서울경기 부근 및 서해안을 중심으로, 그리고 남해안을 중심으로 분포하였다. 대설은 주로 동해안지역(이하 영동 대설)과 남서부 지역(호남형 대설)에서 발생하였다. 위험기상 종류 및 주요 발생지역에 따라 해수면온도 변동성이 조금씩 다르게 나타났으며, 집중호우 발생 시에 진도-제주도-이어도-중국 상하이 방향으로 이어지는 해역에서 해수면온도 변동성이 크게 나타났다. 대설 발생 시, 대설형태와 상관없이, 제주도 남쪽 해상에서 해수면온도 변동성이 작은 영역이 관측되었으며, 130oE, 39oN 부 근 동해상에서 강한 해수면온도 변동성이 나타났다. 해수면온도 변동성이 큰 지역은, 대기-해양 상호작용 메커니즘을 연구하는 기초자료로 사용될 수 있을 뿐만 아니라, 배경대기 에어로졸 관측영역 결정에도 활용될 것이다.
해양법협약 제97조에 따라 공해상에서 발생한 충돌 또는 기타 항행사고에 대한 형사관할권은 가해 선박의 기국 혹은 가해 선원 국적국에서 행사한다. 그러나 이 해양법협약 규정은 고의범까지 포함하는 지의 여부, 편의치적 기국의 관할권 불행사 및 충돌로 인한 해양오염사고의 경우 기타 항행사고에 포함되는 지에 대하여 명확하게 규정하고 있지 않다. 우리나라는 영해이원에서 발생한 충돌사고와 관련하여 외국선박이 가해 선박인 경우 충돌 후 피해 선박에 대한 구조를 이행하지 않고 도주한 경우에도 해양법협약 제97조에 따라 공소권 없음 처분과 판결을 해 왔다. 그러나 이와 같은 형사관할권 관련 처분과 판례가 관행으로 굳어지게 되면 우리 연해를 통항하는 외국운항자들의 경각심 약화, 수사기관의 사기저하, 더 나아가 국민의 생명과 재산에 대한 국가의 보호기능 약화를 초래할 수 있다.
이 논문에서는 해양법협약 제97조와 관련한 법적 문제와 국내외 유사사례의 집행사례를 비교 검토하고, 법리상 충돌 가능성과 해상교통질서 확립과 국민보호를 위한 보충적 형사관할권의 필요성에 대하여 고찰하였다.
We examined the characteristics of egg and larval distributions and catch changes of anchovy in relation to abnormally high sea temperature in the South Sea of Korea in summer 2015 and 2016. The densities of anchovy eggs and larvae in the southern coastal region were lower in July-August 2016 than in July-August 2015. In particular, anchovy eggs and larvae (approximately 5 mm TL) were rarely observed in the coastal region in August 2016 due to the abnormally high SST (up to 28°C), which was above the optimum spawning temperature of anchovy. The catch of non-swimming stage (< 2 cm TL) larval anchovy was lower in July-August 2016 than in July-August 2015. The decreased catch of larval anchovy in July-August 2016 could be attributed to decreased spawning density in June-July 2016. In contrast, the catch of swimming stage (> 2 cm TL) anchovy was increased in July-August 2016. In the summer of 2016, prominent sea temperature near the southern coast of Korea and sea temperature higher than 30°C in the offshore region of the South Sea of Korea could greatly enhance the retention of swimming anchovies in the coastal fishing grounds.
Annual and monthly pollock catches, CPUE and fishing grounds in the high seas of Bering Sea between 1984 and 1992 were analyzed for centroid distribution and bivariate ellipses of trawlers of South Korea, Japan, Poland and China. The catch amount differed by country as 56.1%, 21.7%, 20.4% and 1.8% were caught by Japan, Korea, Poland and China respectively. Japan recorded the highest mean CPUE at 5.7 ton/hour while it was 4.3 ton/hour for Poland, 3.9 ton/hour for Korea and 2.4 ton/hour for China. Cumulative catch varied by month, with the minimum of 137,000 ton in March and the maximum of 848,000 ton in December. Monthly mean of CPUE was the lowest in February (2.0 ton/hour) and the highest in November (6.3 ton/hour). The centroid distribution of monthly fishing ground was located at a southern spot (56° 05'N, 178° 55'E) in January, and it moved anti-clockwise toward 56° 37'N, 178° 24'E in December. Fishing grounds were scattered more by the east-west direction than by the south-north direction. The fishing grounds were similar for Korean, Japanese and Polish trawlers, but Chinese trawlers that fished only from July to December showed distinctively different fishing grounds from the others.
해수면온도는 급변하는 기후를 이해하는 가장 중요한 해양 변수 중의 하나이므로 과학 교과서에는 정확하고 오류없는 해수면온도 영상이 제시되어야 한다. 그러나 고등학교 교과서에 제시된 해수면온도 영상들은 다양한 원인에서 비롯된 많은 오류들을 가지고 있었다. 본 연구는 제 7차 교육과정에 근거한 24종의 고등학교 과학 교과서, 지구과학 I, 지구과학 II 교과서의 36개의 인공위성 해수면온도 영상을 17개 항목에 대하여 분석하였다. 해수면온도 영상 처리 과정에서 생긴 구름 제거, 육지 마스킹, 색상표, 위치 정보, 시간 표시와 관련된 오류와 인공위성에 대한 기본적인 표현 오류를 조사하였다. 예비교사 25명에게 문제가 있는 대표적인 인공위성 영상들을 제시하고 설문을 실시하고 반응을 분석하였다. 그 결과 대부분의 예비교사들은 해수면온도 영상 처리 과정에서 발생할 수 있는 오류에 대하여 인지하지 못하였으며, 해빙, 강수 유입, 한류와 같은 실제 해양현상과 연관지어 해수면온도를 이해하려는 경향을 보였다. 따라서 교과서 해수면온도 영상은 본 연구에서 제시한 세부 항목들을 고려하여 정확하게 처리되어야 한다.
In spite of many efforts, in the design of high speed fishing vessel the sea-keeping performance improvement without neglection of resistance-propulsion performance by hull form itself has its limitations. In this paper, the development of sea-keeping improving appendage pitching and trim improver for high speed planing hull on behalf of the hull form of fishing vessel has been introduced. The developed appendage verified its effectiveness in the full scale test and also has been proved the better resistance performance in the model test and full scale test.
El Niño is the largest fluctuation in the climate system, and it can lead to effects influencing humans all over the world. An El Niño occurs when sea surface temperatures in the central and eastern tropical Pacific Ocean become substantially higher than average. We investigated the change in sea surface temperature in the Pacific Ocean during the El Niño period of 2015 and 2016 using the advanced very-high-resolution radiometer (AVHRR) of NOAA Satellites. We calculated anomalies of the Pacific equatorial sea surface temperature for the normal period of 1981–2010 to identify the variation of the 2015 El Niño and warm water area. Generally, the warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America during an El Niño period. However, we identified an additional warm water region in the Niño 1+2 and Peru coastal area. This indicates that there are other factors that increase the sea surface temperature. In the future, we will study the heat coming from the bottom of the sea to understand the origin of the heat transport of the Pacific Ocean.
Meteo-tsunamis are tsunamis that are typically caused by strong atmospheric instability (e.g., pressure jumps) in low pressure systems, but some meteo-tsunamis in winter can be caused by local atmospheric instability in high pressure systems (e.g., the Siberian High). In this study, we investigated a meteo-tsunami event related to a high pressure system that occurred during winter on the Yellow Sea in 2005. Sea level data from tidal stations were analyed with a high-pass filter, and we also performed synoptic weather analyses by using various synoptic weather data (e.g., surface weather charts) collected during the winter season(DJF) of 2005. A numerical weather model (WRF) was used to analyze the atmospheric instability on the day of the selected event (21 Dec. 2005). On the basis of the results, we suggest that the meteo-tsunami triggered by the high pressure system occurred because of dynamic atmospheric instability induced by the expansion and contraction of the Siberian High.
Water temperature in the eastern part of the Yellow Sea (EYS) during winter (JFM) and summer (JJA) from 1964 to 2009 and Siberian High Pressure Index (SHI) and Arctic Oscillation index (AOI) during winter (JFM) from 1950 to 2011 were used to analyze long-term variation in oceanic and atmospheric conditions and relationship between winter and summer bottom water temperature. Winter water temperature at 0, 30 and 50 m had fluctuated highly till the late of 1980s, but after this it was relatively stable. The long-term trends in winter water temperature at both depths were separated with cold regime and warm regime on the basis of the late 1980s. Winter water temperature at 0m and 50m during warm regime increased about 0.9°C and 1.1°C respectively compared to that during cold regime. Fluctuation pattern in winter water temperature matched well with SHI and AOI The SHI had negative correlation with water temperature at 0 m (r=-0.51) and 50 m (r=-0.58). On the other hand, the AO had positive correlation with Winter water temperature at 0 m (r=0.34) and 50 m (r=0.45). Cyclic fluctuation pattern of winter water temperature had a relation with SHI and AO, in particular two to six-year periodicity were dominant from the early of the 1970s to the early of the 1980s. Before the late of 1980s, change pattern in winter water temperature at 0 and 50 m was similar with that in the bottom water temperature during summer, but after this, relationship between two variables was low.
현재 모형선을 이용한 선형성능 검증설비는 예인수조와 회류수조 두설비가 주로 이용된다. 이들 설비는 주로 저속 대형선박을 위해 기법들로 소형 고속어선 및 고속레저선박의 저항성능 평가를 수행하기에 전차의 속도와 유속이 목표속도에 미치지 못해 어려움이 존재한다. 따라서 고속 선박의 저항성능 평가를 위해 새로운 기법 정립 연구가 필요하다. 이에 고속선의 저항성능 시험을 위해 실제 해상에서 선박을 이용한 모형시험을 고안하고 측정시스템을 구성하였다. 시스템구성은 총 8개의 파트로 구성되어 있으며, 시스템 검증을 위해 C.W.C에서 저속선의 모형을 이용하여 시험을 수행하여 시스템 적용 가능성을 검증하였다. 또한 실제 해상에서 고속선 모형선을 이용하여 시험을 수행하였으며, 이 결과를 CFD해석 결과와 비교하여 실해상 모형시험 방법의 가능성을 확인 하였다.
Accurate simulation of the meteorological field is very important to assess the wind resources. Some researchers showed that sea surface temperature (SST) plays a leading role on the local meterological simulation. New Generation Sea Surface Temperature (NGSST), Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA), and Real-Time Global Sea Surface Temperature (RTG SST) have different spatial distribution near the coast and OSTIA shows the best accuracy compared with buoy data in the southeastern coast of the Korean Peninsula. Those SST products are used to initialize the Weather Research and Forecasting (WRF) Model for November 13-23 2008. The simulation of OSTIA shows better result in comparison with NGSST and RTG SST. NGSST shows a large difference with OSTIA in horizontal and vertical wind fields during the weak synoptic condition, but wind power density shows a large difference during strong synoptic condition. RTG SST shows the similar patterns but smaller the magnitude and the extent.
High concentration of chlorophyll a occurred around the Ulleung Warm Eddy off Ulleung Island in the East Sea of Korea in spring season. The abnormal distributions of chlorophyll a were captured by satellite remote sensing and measured field data. The temporal and spatial scale of the abnormal distributions were around 20 days and 50km diameter off Ullung Island. The anomalies were quantified by estimated chlorophyll a derived from OCM and SeaWiFS ocean color data from 2000 to 2004.
The origin of abnormal high concentrations was estimated by this study. It was that suspended material discharged from the Nakdong River and the coastal water located in the southeastern part of Korean Peninsula moved to northeastern coast, and then moved to off Ullung Island. The high chlorophyll a concentrations including inorganic materials were accumulated by anticyclonic eddy such as the Ullung Warm Eddy around Ullung Island in the East Sea of Korea in spring season.