• 한국환경과학회지
• /
• 제32권11호
• /
• pp.841-852
• /
• 2023

In this study, the significant wave height and wave period of a specially designed observation system that connected two drifting buoys to an ocean data buoy was observed for 23 days from February 7 to 29, 2020, and the results were compared and analyzed. The results indicated that, in comparison to the ocean data buoy, the drifting buoy exhibited greater variability in significant wave height over shorter time intervals. The wave period of the ocean data buoy also appeared longer than that of the drifting buoy. The greater the observed significant wave height and wave period from both the ocean data and drifting buoys, the more pronounced the differences between the two observation instruments become. Moreover, the study revealed that the disparity in observation methods between the ocean data and drifting buoys did not significantly affect the significant wave height characteristics, as long as the period remained unchanged for up to half of the observation time.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2019년도 춘계학술대회
• /
• pp.119-120
• /
• 2019

X-band 항해용 레이더를 이용한 파랑계측시스템의 파고계측 정확성 검증을 위해 울릉도 주변해역의 부이 유의파고값을 분석하여 결과의 타당성을 확보하였다. 특히 울릉도부이(해양기상부이), 울릉읍파고부이, 구암파고부이 및 혈암파고부이의 유의파고를 계절별로 분석하여 레이더식 파랑계측 결과와의 상관계수를 도출하고 분석하였다.

• 수산해양기술연구
• /
• 제53권4호
• /
• pp.309-316
• /
• 2017

In this paper, numerical modeling is conducted to analyze the tension of an anchor line by varying the size and drag coefficient of a buoy when the trapnet is influenced by the wave and the current simultaneously. A mass-spring model was used to analyze the behavior of trapnet underwater under the influence of waves and current. In the simulation of numerical model, wave height of 3, 4, 5 and 6 m, a period of 4.4 s, and the flow speed of 0.7 m/s were used for the wave and current condition. The drag coefficients of buoy were 0.8, 0.4 and 0.2, respectively. The size of buoy was 100, 50 and 25% based on the cylindrical buoy ($0.0311m^3$) used for swimming crab trap. The drag coefficient of the trapnet, the main model for numerical analysis, was obtained by a circular water channel experiment using a 6-component load cell. As a result of the simulation, the tension of the anchor line decreased proportional to buoy's drag coefficient and size; the higher the wave height, the greater the decrease rate of the tension. When the buoy drag coefficient and size decreased to one fourth, the tension of the anchor line decreased to a half and the tension of the anchor line was lower than the holding power of the anchor even at 6 m of wave height. Therefore, reducing the buoy drag coefficient and size appropriately reduces the trapnet load from the wave, which also reduces the possibility of trapnet loss.

• 대한원격탐사학회지
• /
• 제29권6호
• /
• pp.631-644
• /
• 2013

Significant Wave Height (SWH) data measured by satellite altimeters (Topex/Poseidon, Jason-1, Envisat, and Jason-2) were validated in the seas around Korea by comparison with wave height measurements from marine meteorological buoy stations of Korea Meteorological Administration (KMA). A total of 1,070 collocation matchups between Ku-band satellite altimeter data and buoy data were obtained for the periods of the four satellites from 1992 to the present. In the case of C-band and S-band observations, 1,086 matchups were obtained and used to assess the accuracy of satellite SWH. Root-Mean-Square (RMS) errors of satellite SWH measured with Ku-band were evaluated to roughly 0.2_2.1 m. Comparisons of the RMS errors and bias errors between different frequency bands revealed that SWH observed with Ku-band was much more accurate than other frequencies, such as C-band or S-band. The differences between satellite SWH and buoy wave height, satellite minus buoy, revealed some dependence on the magnitude of the wave height. Satellite SWH tended to be overestimated at a range of low wave height of less than 1 m, and underestimated for high wave height of greater than 2 m. Such regional characteristics imply that satellite SWH should be carefully used when employed for diverse purposes such as validating wave model results or data assimilation procedures. Thus, this study confirmed that satellite SWH products should be continuously validated for regional applications.

• 한국해양학회지:바다
• /
• 제8권3호
• /
• pp.274-284
• /
• 2003

본 연구에서는 제 3세대 파랑 모형인 WAVEWATCH-III모델 (Tolman, 1999)과 기상청 해양기상 관측부이(4기) 자료를 이용하여 파랑인자 특성에 관한 분석이 이루어졌다. 풍속이 증가한 후 약 2-3시간 후에 유의파고가 커지고, 풍속과 유의파고의 상관성은 비교적 외해에 위치한 동해 부이에서 크게 나타났다. 육풍 발생 시 두 인자 사이의 상관계수 값이 급격히 떨어졌으며, 풍속과 파고 편차 시계열 자료에서는 동채부이를 제외하고 지배적인 조석주기가 발견되었다 부이 자료와의 비교를 통하여 WAVEWATCH-III모델의 파랑 모의 성능을 진단한 후에, 쿠로시오 해역과 동해 해역의 수치 실험을 통해서 파랑의 진행 방향에 대해 반대 방향으로 해류가 흐를 때는 파고는 높아지고, 파장은 짧아진다는 사실을 재확인했다. 또한 이러한 효과는 풍속이 약하거나 해류가 강할 때 더 커지는 양상을 나타냈으며 이에 대한 정량적인 결과를 제시하였다.

• 수산해양교육연구
• /
• 제26권5호
• /
• pp.1013-1025
• /
• 2014

Marine meterological characteristics off the coast in the East Sea between 2006 and 2013 were investigated by comparing the high wind-wave alert and moored-measured significant wave high. Monthly and yearly variations of the high wind-wave alert duration off the coast in the central part of the East Sea are correlated with those of the significant wave height measurement with their minima in June and 2008 and maxima in December and 2012. Both the high wind-wave alert duration and significant wave height increase remarkably during 2010-2013 when compared with during 2006-2009. The remarkable increase, occurring dominantly in December, seems to be related with Arctic oscillation variability. However, the comparisons reveal that only about a half of high wind-wave alerts satisfy the criteria for issuing the high wind-wave alert. To issue the high wind-wave alert, the wind speed at the sea should exceed 14 m/s or the significant wave height should be higher than 3 m. The high wind-wave alerts unsatisfying the significant wave height criteria are issued mainly during spring and summer. These results imply that additional surface buoy moorings in the open basin of the East Sea are necessary for more accurate issue of the high wind-wave alert.

• 한국전자통신학회논문지
• /
• 제6권2호
• /
• pp.268-273
• /
• 2011

태풍 및 해상 악천후에 견디며 무중단 운영, 실시간 관측할 수 있는 고급 사양의 부이식 파고 관측부이 시스템 개발 시급한 상황이다. 본 연구에서 부이식 파고관측 시스템을 국산화 개발하여 실시간 관측(풍속, 기온, 기압)를 부이에 추가하여 해양에 설치하고 해양의 자료를 실시간으로 전송하는 시스템 개발 하였다. 개발된 부이식 파고관측 시스템을 통하여 매년 해상에 투하하는 해양기상부이(표류형 파향파고계)의 수요를 충족할 것으로 기대된다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제32권1호
• /
• pp.169-174
• /
• 2008

Floating devices, such as a cavity resonance device take advantage of both the water motion and the wave induced motions of the floating body itself. The wave energy converter is known commercially as the WAGB(Wave Activated Generator Buoy) and is used in some commercially available buoys to power navigation aids such as lights and horns. This wave energy converter consists of a circular floatation body which contains a vertical center pipe that has free communication with the sea. A theoretical analysis of this power generated by a pneumatic type wave energy converter is performed and the results obtained from the analysis are used for a real wave energy converter for buoy. This paper presents the analysis results and the design method for the WEC(Wave Energy Converter), and the associate results are application to the commercially available WEC for buoy. Maximum performance of WEC occurs at resonance with driving waves. The analysis of WEC is performed with LabVIEW program, and the design method of WEC for buoy is suggested in this paper.

• 수산해양기술연구
• /
• 제50권3호
• /
• pp.233-243
• /
• 2014

The difference of mooring tension by type of buoy was investigated in the circulating water channel and the wave tank for deducting the most stable buoy from the current and the wave condition. 5 types of buoy made up of short cylinder laid vertically (CL-V), short cylinder laid horizontally (CL-H), capsule (CS), sphere (SP) and long cylinder (CL-L) were used for experiments. A mooring line and a weight were connected with each buoy. A tensile gauge was installed between a mooring line and a weight. All buoy's mooring tension was measured at the same time for the wave test with periods of 1.5~3.0 sec and wave heights of 0.1~0.3 m, and the current test with flow speeds of 0.2~1.0 m/sec. As a result, the order of tension value in the wave test was CL-H > CL-V > SP > CS > CL-L. In the current test CL-V and CL-H were recorded in the largest tension value, whereas SP has the smallest tension value. So it seems that SP buoy is the most effective in the location affected by fast current. CS is predicted to be suitable for a location that influence of wave is important more than that of current if practical use in the field is considered. And it was found that the difference of mooring tension among buoys in wave is related to the product of the cross sectional area and the drag coefficient for the buoy's bottom side in high wave height. The factor for the current condition was not found. But it was supposed to be related to complex factors like a dimension and a shape by buoy's posture to flow.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2001년도 춘계학술대회 논문집
• /
• pp.216-221
• /
• 2001

In this paper, statistical properties of waves in the sea area of Pohang, Korea are examined absed on 1998-1999's wave data from directional wave buoy which is located Pohang(Janggigog). Wave data aquisition rate, monthly maximium, minimum and mean wave heights, frequency of wave direction are summarized. Wave height and period scatter diagrams and n-year return period wave heights are estimated. Wave periods of maximum wave heights are also estimated.