• 제목/요약/키워드: ocean

검색결과 24,562건 처리시간 0.045초

해양 심층수의 안정성 조사 및 분석 (I) (Investigation and Analysis of the Characteristic Stability of Deep Ocean Water (I))

  • 김현주;문덕수;정동호;윤상준
    • 한국해양환경ㆍ에너지학회지
    • /
    • 제7권1호
    • /
    • pp.30-34
    • /
    • 2004
  • 동해 해양심층수의 자원적 안정성을 평가하기 위하여 2001년 3월부터 2002년 2월까지 조사한 해양조사 및 수질분석이 수행되었다. 해양심층수 시범개발해역 및 강원북부 주변해역에 대한 해양자원적 수질특성의 시공간적 변동이 분석 및 비교되었다. 특히, 자원성이 인증된 해양심층수의 안정적 공급을 위해 필요한 취수 수심의 결정을 위해 월별 수온 및 염분의 연직분포에 대한 조사해석 및 수질분석 이 이루어져 고찰되었다.

  • PDF

DEVELOPMENT OF GOCI/COMS DATA PROCESSING SYSTEM

  • Ahn, Yu-Hwan;Shanmugam, Palanisamy;Han, Hee-Jeong;Ryu, Joo-Hyung
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
    • /
    • pp.90-93
    • /
    • 2006
  • The first Geostationary Ocean Color Imager (GOCI) onboard its Communication Ocean and Meteorological Satellite (COMS) is scheduled for launch in 2008. GOCI includes the eight visible-to-near-infrared (NIR) bands, 0.5km pixel resolution, and a coverage region of 2500 ${\times}$ 2500km centered at 36N and 130E. GOCI has had the scope of its objectives broadened to understand the role of the oceans and ocean productivity in the climate system, biogeochemical variables, geological and biological response to physical dynamics and to detect and monitor toxic algal blooms of notable extension through observations of ocean color. The special feature with GOCI is that like MODIS, MERIS and GLI, it will include the band triplets 660-680-745 for the measurements of sun-induced chlorophyll-a fluorescence signal from the ocean. The GOCI will provide SeaWiFS quality observations with frequencies of image acquisition 8 times during daytime and 2 times during nighttime. With all the above features, GOCI is considered to be a remote sensing tool with great potential to contribute to better understanding of coastal oceanic ecosystem dynamics and processes by addressing environmental features in a multidisciplinary way. To achieve the objectives of the GOCI mission, we develop the GOCI Data Processing System (GDPS) which integrates all necessary basic and advanced techniques to process the GOCI data and deliver the desired biological and geophysical products to its user community. Several useful ocean parameters estimated by in-water and other optical algorithms included in the GDPS will be used for monitoring the ocean environment of Korea and neighbouring countries and input into the models for climate change prediction.

  • PDF

수조실험을 통한 해저지반 굴삭용 워터젯 장비의 성능평가에 관한 연구 (Study on Performance Evaluation of Subsea Waterjet Trenching Machine Using Water Tank)

  • 나경원;조효제;백동일;황재혁;한성훈;장민석;김재희
    • 한국해양공학회지
    • /
    • 제29권6호
    • /
    • pp.470-474
    • /
    • 2015
  • The demand for subsea cables and pipelines that transfer marine energy resources onshore has recently increased. Laying these underground after trenching is one engineering method to stabilize exposed subsea cables and pipelines. This experimental study found the optimum conditions for operating two types of waterjet arms mounted on an ROV trencher. A waterjet arm for trenching the seabed was scaled down at a ratio of 1:6, and a comparative analysis was conducted using diverse parameters. The results of this research provide a practical fundamental database to assist in making decisions about the ROV trencher performance in advance.

A Study on the Dynamic Analysis of Mooring System During Hook-up Installation

  • Lee, Min Jun;Jo, Hyo Jae;Lee, Sung Wook;Hwang, Jea Hyuk;Kim, Jea Heui;Kim, Young Kyu;Baek, Dong Il
    • 한국해양공학회지
    • /
    • 제34권5호
    • /
    • pp.285-293
    • /
    • 2020
  • This study evaluated the Hook-up installation of an offshore site construction process, which is the final step in an offshore site installation process. During Hook-up installation, the offshore structure can have a detrimental effect on the work stability due to low-frequency motion. Moreover, economic costs can be incurred by the increase in available days of a tugboat. Therefore, this study developed a numerical analysis program to assess the dynamic behavior of mooring systems during hook-up installation to analyze the generally performed installation process and determine when the tugboat should be released. In this program, the behavior of an offshore structure was calculated using Cummin's time-domain motion equation, and the mooring system was calculated by Lumped mass method (LMM). In addition, a tugboat algorithm for hook-up installation was developed to apply the Hook-up procedure. The model used in the calculations was the barge type assuming FPSO (Floating production storage and off-loading) and has a taut mooring system connected to 16 mooring lines. The results of the simulation were verified by comparing with both MOSES, which is a commercial program, and a calculation method for restoring coefficient matrix, which was introduced by Patel and Lynch (1982). Finally, the offset of the structure according to the number of tugboats was calculated using the hook-up simulation, and the significant value was used to represent the calculation result.

이어도 해양과학기지에서 측정한 수중 배경소음의 분석 (Analysis of Underwater Ambient Noise measured at leodo Ocean Research Station)

  • 최복경;김봉채;김병남
    • 한국음향학회:학술대회논문집
    • /
    • 한국음향학회 2004년도 추계학술발표대회논문집 제23권 2호
    • /
    • pp.415-416
    • /
    • 2004
  • 이어도 해양과학기지에서 해수중으로 청음기를 내려 2004년 7월에 3일간 연속적으로 수중 배경소음을 녹음 하였다. 측정된 주파수스펙트럼을 통계처리하고 또한 시계열 신호의 특성을 분석하였다. 해상 풍속도 관측하였다. 전체적으로 한반도 주변 해양의 배경소음에 비해 상대적으로 소음레벨이 작은 경향을 보였다.

  • PDF

2007년 3월 한국 서해안에 발생한 해양장파의 형성과 성장과정 (Generation and Growth of Long Ocean Waves along the West Coast of Korea in March 2007)

  • 최병주;박용우;권경만
    • Ocean and Polar Research
    • /
    • 제30권4호
    • /
    • pp.453-466
    • /
    • 2008
  • In order to examine the generation mechanism of long ocean waves along the west coast of Korea and to understand the amplification process of the long ocean waves, sea level, atmospheric pressure and wind data observed every minute from 2007 March 29 to 2007 April 1 were analyzed and onedimensional numerical ocean model experiments were performed. An atmospheric pressure jump propagated southeastward from Backryungdo to Yeonggwang along the west coast of Korea with speed of $13{\sim}27\;m/s$ between 2007 March 30 23:00 and 2007 April 1 1:30. Average magnitude of pressure jump was 4.2 hPa. As a moving atmospheric jump propagated from north to south along the coast, long ocean waves were generated and the sea level abnormally rose or fell at Anheung, Kunsan, Wido and Yeonggwang. Average amplitude of sea level rise (or fall) was about 113.6 cm. In a one-dimensional numerical ocean model, nonlinear shallow water equations were numerically integrated and a moving atmospheric pressure jump with traveling speed of 24 m/s was used as an external force. While the atmospheric pressure jump travels over 60 m depth ocean, a long ocean wave is generated. Because the propagation speed of the atmospheric jump is almost equal to that of the long ocean wave, Proudman resonance occurs and the long ocean wave amplifies. As the atmospheric pressure jump moves into the coastal area shallower than 60 m, the speed of the long ocean wave decreases and Proudman resonance effect decreases. However, the amplitude of the long ocean wave increases and wave length becomes shorter because of shoaling effect. When the long ocean wave hits the land boundary, amplitude of the long ocean wave drastically amplifies due to reflection. Data analysis and numerical experiments suggest that the southeastward propagation of an atmospheric pressure jump over the shallow ocean, which is a necessary condition for Proudaman resonance, generated the long ocean waves along the west coast of Korea on 2007 March 31 and the ocean waves amplified due to shoaling effect in the coastal area and reflection at the shore.