• 제목/요약/키워드: ocean climate change

검색결과 492건 처리시간 0.03초

Wave Reflection over an Arbitrarily Varying Topography

  • Cho, Yong-Sik;Lee, Changhoon
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 1997년도 정기학술강연회 발표논문 초록집 Annual Meeting of Korean Society of Coastal and Ocean Engineers
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    • pp.39-44
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    • 1997
  • As wind waves generated in deep water approach nearshore zone, they experience various physical phenomena caused by bathymetric variations, nonlinear interactions among different wave components and interferences with man-made coastal structures. Among these, the bathymetric variations may play a significant role in the change of wave climate. The accurate calculation of reflection and transmission coefficients of incident waves over a bottom topography is indispensible for the proper and economical design of coastal structures. (omitted)

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북서 태평양에서의 지구온난화로 인한 $CO_2$ 4배증시 해수면의 공간적 변화 (Steric sea level change due to global warming in the northwestern Pacific Ocean for a $CO_2$ quadrupling)

  • 최병호;김동훈;최영진
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 2000년도 한국해안해양공학발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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    • pp.188-194
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    • 2000
  • 지역적 기후변동은 전구평균 변화와는 다른 양상을 가진다. 그러나, 현재 전구적 기후변동과 해수면의 변화가 국지적으로 미칠 영향에 대한 추정능력은 매우 제한되어 있다. 본 연구에서는 NCAR(국립 대기 연구소)의 CSM (Climate System Model) 버전 1.2를 이용하여 전구뿐만 아니라 국지적인 시뮬레이션을 함께 수행하였다, 특히 북서태평양과 그 부근지역에 대한 해수변화를 중점적으로 연구했다. (중략)

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Development of high-resolution atmosphere ocean coupled model and global warming projection with Earth Simulator -A whole research plan and result in FY2002-

  • Maruyama, Koki
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 2003년도 한국해안해양공학발표논문집
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    • pp.18-27
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    • 2003
  • The goal of the UN Framework Convention on Climate Change (UNFCCC) is to stabilize atmospheric CO2 concentration for preventing global warming in future. However, there are many unknown factors regarding stabilization of CO2 concentration. What level of concentration should be appropriate to prevent global warming? When should we stop the increase of CO2 concentration\ulcorner What kind of countermeasures of reducing CO2 emission will be available for CO2 stabilization?(omitted)

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수리화학적 환경 추적자를 이용한 강원도 석호지역에서의 지하수-지표수 상호작용에 대한 연구 (Determining Groundwater-surface Water Interaction at Coastal Lagoons using Hydrogeochemical Tracers)

  • 김동훈;이정윤;조수영;문희선;정윤영;박예진;오용화
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제28권2호
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    • pp.1-11
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    • 2023
  • Groundwater-surface water interaction was evaluated using water quality parameters (temperature and electrical conductivity), distributions of stable water isotopes (δ2H and δ 18O), and Rn-222 in lagoon water, groundwater, and seawater at three coastal lagoons (Songji (SJ), Youngrang (YR), and Sunpo (SP) Lagoon) in South Korea. From the results of composition and distributions of δ2H and δ18O, it was found that groundwater fraction of lagoon water in YR Lagoon (76%) was slightly higher than those of SJ (42%), and SP (63%) Lagoon. Based on Rn-222 mass balance model, groundwater discharge into SJ Lagoon in summer 2020 was estimated to be (3.2±1.1)×103 m3 day-1, which showed a similar or an order of magnitude higher than the results of previous studies conducted in coastal lagoons. This study can provide advanced techniques to evaluate groundwater-surface water interaction in coastal lagoons, wetlands, and lakes, and help to determine the effects of groundwater on coastal ecosystems.

Accelerated Seaward Growth of Tidal Sand Bar during Giant Dyke Construction off the Mangyung River Mouth, West Coast of Korea

  • Lee, Hee-Jun;Choi, Kang-Won;Eo, Dae-Su;Chu, Yong-Shik
    • Journal of the korean society of oceanography
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    • 제36권3호
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    • pp.72-82
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    • 2001
  • The progress of giant dyke construction off the Mangyung and Donajin rivers, has yielded enormous impact on the estuarine environment, both hydrodynamically and sedimentologically. Especially the inter-dyke gap in the northern Saemankeum area, 4 km wide between Yamido and Piungdo, has acted as an artificial tidal inlet. Due to such a changed geometry, tidal regime has been reversed from being flood- to ebb-dominated with a directional change from NE-SW to E-W. As a result, a large tongue-like tidal sand bar (named Saemankeum Bar) has conspicuously grown seaward through the artificial tidal inlet. The Saemankeum Bar composed of well-sorted very fine sands (3.0-3.5${\phi}$) has grown at a rate of 1.63 km/yr for the past three yews (1996-1998). Such a rapid growth of the sand bar is attributed to enhanced sediment supply derived from the degradation of former tidal sand bars at the mouth of the Mangyung River. Eventually the reworking of the tidal sand bars also caused the pre-existing tidal channels to be wider, deeper and more straightened. All of these phenomena well examplify the critical effect of artificial modifications on the natural estuarine environments.

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Effect of elevated pCO2 on thermal performance of Chattonella marina and Chattonella ovata (Raphidophyceae)

  • Lim, Myeong Hwan;Lee, Chung Hyeon;Min, Juhee;Lee, Hyun-Gwan;Kim, Kwang Young
    • ALGAE
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    • 제35권4호
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    • pp.375-388
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    • 2020
  • Ocean acidification and warming, identified as environmental concerns likely to be affected by climate change, are crucial determinants of algal growth. The ichthyotoxic raphidophytes Chattonella species are responsible for huge economic losses and environmental impact worldwide. In this study, we investigated the impact of CO2 on the thermal performance curves (TPCs) of Chattonella marina and Chattonella ovata grown under temperatures ranging from 13 to 34℃ under ambient pCO2 (350 μatm) and elevated pCO2 (950 μatm). TPCs were comparable between the species or even between pCO2 levels. With the exception of the critical thermal minimum (CTmin) for C. ovata, CTmin for C. marina and the thermal optimum (Topt) and critical thermal maximum (CTmax) for both species did not change with elevation of pCO2 levels. While CO2 enrichment increased the maximum photosynthetic rates (Pmax) up to 125% at the Totp of 30℃, specific growth rates were not significantly different under elevated pCO2 for the two species. Overall, C. ovata is likely to benefit from climate change, potentially widening its range of thermal tolerance limit in highly acidic waters and contributing to prolonged phenology of future phytoplankton assemblages in coastal waters.

정지궤도 해색탑재체(GOCI) 표층유속 추정을 위한 SeaWiFS 해색자료의 응용 (Application of SeaWiFS Chlorophyll-a Ocean Color Image for estimating Sea Surface Currents from Geostationary Ocean Color Imagery (GOCI) data)

  • 김응;노영재;전동철
    • 대한원격탐사학회지
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    • 제26권2호
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    • pp.209-220
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    • 2010
  • 해양현상을 이해하기 위한 관측분야의 노력 중에서 해류 정보의 생산은 가장 어려운 작업 중의 하나이다. 이를 극복하기 위한 대안으로서 연속 화상 자료로부터 해류벡터를 추정하려는 많은 연구들이 진행 되고 있다. 본 연구에서는 한반도 주변의 SeaWiFS (Sea-viewing Wide Field-of-view Sensor) chlorophyll-a 해색 자료와 AVHRR/SST 를 이용하여 연속 화상 사이의 유사한 형태를 추적하는 최대상 관계수법을 사용한 표층 유속 벡터의 추정을 시도하였다. 한국의 남해역에서 적용한 유속 벡터 결과는 해면 고도계를 이용한 지형류, ADCP 관측 결과와 비교하여 유속은 약 15% 정도 작고, 유향은 약 $36^{\circ}$의 차이로 근접하여 기존 연구 결과에 비해 양호하게 나타났다. 이는 향후 GOCI 자료의 응용적 측면에서 매우 고무적이다.

Impact of predicted climate change on groundwater resources of small islands : Case study of a small Pacific Island

  • Babu, Roshina;Park, Namsik
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2018년도 학술발표회
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    • pp.145-145
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    • 2018
  • Small islands rely heavily on groundwater resources in addition to rainwater as the source of freshwater since surface water bodies are often absent. The groundwater resources are vulnerable to sea level rise, coastal flooding, saltwater intrusion, irregular pattern of precipitation resulting in long droughts and flash floods. Increase in population increases the demand for the limited groundwater resources, thus aggravating the problem. In this study, the effects of climate change on Tongatapu Island, Kingdom of Tonga, a small island in Pacific Ocean, are investigated using a sharp interface transient groundwater flow model. Twenty nine downscaled General Circulation Model(GCM) predictions are input to a water balance model to estimate the groundwater recharge. The temporal variation in recharge is predicted over the period of 2010 to 2099. A set of GCM models are selected to represent the ensemble of 29 models based on cumulative recharge at the end of the century. This set of GCM model predictions are then used to simulate a total of six climate scenarios, three each (2010-2039, 2040-2069, and 2070-2099) under RCP 4.5 and RCP 8.5. The impacts of predicted climate change on groundwater resources is evaluated in terms of freshwater volume changes and saltwater ratios in pumping wells compared to present conditions. Though the cumulative recharge at the end of the century indicates a wetter climate compared to the present conditions the large variability in rainfall pattern results in frequent periods of groundwater drought leading to saltwater intrusion in pumping wells. Thus for sustaining the limited groundwater resources in small islands, implementation of timely assessment and management practices are of utmost importance.

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생지화학모델링을 이용한 동중국해 해양-대기 CO2교환량의 변화 연구 (Investigation of Change in Air-Sea CO2 Exchange over the East China Sea using Biogeochemical Ocean Modeling)

  • 박영규;최상화;예상욱;이정석;황진환;강성길
    • Ocean and Polar Research
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    • 제30권3호
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    • pp.325-334
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    • 2008
  • A biogeochemical model was used to estimate air-sea $CO_2$ exchange over the East China Sea. Since fresh water discharge from the Changjiang River and relevant chemistry were not considered in the employed model, we were not able to produce accurate results around the Changjiang River mouth. This factor aside, the model showed that the East China Sea, away from the Changjiang River mouth, takes approximately $1.5{\sim}2\;mole\;m^{-2}yr^{-1}$ of $CO_2$ from the atmosphere. The model also showed that biological factors modify the air-sea $CO_2$ flux by only a few percent when we assumed that biological activity increased two-fold. Therefore, we can argue that the biological effect is not strong enough over this area within the framework of the current phosphate-based biological model. Compared to the preindustrial era, in 1995 the East China Sea absorbed $0.4{\sim}0.8\;mole\;m^{-2}yr^{-1}$ more $CO_2$. If warming of the sea surface is considered, in addition to the increase in atmospheric $CO_2$ concentration, by 2045 the East China Sea would absorb $0.2{\sim}0.4\;mole\;m^{-2}yr^{-1}$ less $CO_2$ compared to the non-warming case.

다중 GPS를 이용한 변위거동 연구

  • 손호웅;이강원;박은호
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2009년도 춘계학술발표회 논문집
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    • pp.95-100
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    • 2009
  • Global warming melts polar ice, changes ocean currents, creates variation of local climate, and inundates low-altitude regions resulting in disasters to mankind. Accordingly, developed countries including U.S.A. and U.K. spend great amounts of efforts and money to plan and manage research activities on polar ice which is regarded as a key indicator of climate change. The proposed research aims to provide basic information for chasing and monitoring the melting phenomena of polar ice through multiple GPS to enhance the GPS quality.

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