• 제목/요약/키워드: Oceanic variability

검색결과 61건 처리시간 0.027초

Satellite-derived estimates of interannual variability in recent oceanic $CO_2$ uptake

  • Park Geun-Ha;Lee Kitack
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.152-153
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    • 2004
  • The growth rate of atmospheric $CO_2$ undergoes significant interannual variability, largely due to temporal variability of partitioning of $CO_2$ between terrestrial biosphere and ocean. In the present paper, as a follow-up to the work by Lee et al. [1], we estimated the year-to-year variability in net global air-sea $CO_2$ fluxes between 1982 and 2003 from observed changes in wind speed and estimated changes in ${\Delta}pCO_2$ Changes in $pCO_{25W}$ were inferred from global records of sea surface temperature (SST) anomalies and seasonally varying SST dependence of $pCO_{25W}$. The modeled interannual variability of $\pm0.2\;Pg\;C\;yr^{-1}\;(1{\sigma})$ from the present work is significantly smaller than the values deduced from atmospheric observations of $^{1.3}CO_2/CO_2$ in conjunction with different atmospheric transport models, but it is closer to the recent estimates inferred from a 3-D ocean biogeochemical model and atmospheric transport models constrained with extensive observations of atmospheric $CO_2$.

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PHYTOPLANKTON BLOOMING AND OCEANIC CONDITIONS IN THE SEAS AROUND THE SPRATLY ISLANDS

  • Dien, Tran Van;Tang, DanLing;Kawamura, Hiroshi
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.529-532
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    • 2006
  • The oceanic currents in the South China Sea (SCS) are strongly influenced by monsoon winds. A review on the SCS currents has indicated that previous studies have pointed out an anticyclonic circulation in the area between the southern Vietnam coast and the Spratly Islands. However, its detail is not understood because of less information of in situ observations. The physical-biological interaction is quite new research area, which has been established and promoted by means of the ocean color remote sensing. Temporal/spatial variability of the phytoplankton activities are well captured by ocean color (OC) -derived Chlorophyll-a images. Combining the OC-Chl-a and the other high-resolution satellite data (e.g., SST images), the biological aspects of oceanographic variation is well described. The blooming phenomena in the area between the southern Vietnam coast and the Spratly islands are further investigated. Change in the wind-system related to the El Nino generates upwelling/SST-cooling in the sea south of the Spratly Islands through the air-sea-land interaction was studied. The seasonal upwelling is also associated with the harmful algal bloom (HAB) off two side of Indochina Peninsula have investigated. The seasonal variation of SCS phytoplankton blooming and related oceanic conditions in Vietnam coast was observed. Ocean color satellite data has effective contribute to study the oceanic condition and phytoplankton blooming in South China Sea.

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기후 변환와 해양 열염분 순환 (Climate Change and the Thermohaline Circulation of the Oceans)

  • 박영규
    • 대기
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    • 제15권1호
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    • pp.69-74
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    • 2005
  • In this short article, oceanic processes that could have strong effect on the climate have been explained while focusing on the oceanic thermohaline circulation (THC). First, the structure of THC is explained using a simple scaling law. Then, the thermohaline catastrophe, which is believed to be a cause of a rapid climate changes observed in paleoclimate records, and interdecadal variations in THC are explained. The interactions between the oceans and $CO_2$ are also mentioned briefly.

THE STUDY OF SPATIAL AND TEMPORAL VARIABILITY OF THE KUROSHIO EXTENSION USING REMOTE SENSING DATA WITH APPLICATION OF DATA-FUSION METHODS

  • Kim Woo-Jin;Park Gil- Yong;Lim Se-Han;OH Im-Sang
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.434-436
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    • 2005
  • Analysis method using remote sensing data is one of the effective ways to research a spatial and temporal variability of the mesoscale oceanic motions. During past several decades, many researchers have been getting comprehensive results using remote sensing data with application of data fusion methods in many parts of geo-science. For this study, we took the integration and fusion of several remote sensing data, which are different data resolution, timescale and characteristics, for improving accurate analysis of variation of the Kuroshio Extension. Furthermore, we might get advanced ways to understand the variability of the Kuroshio Extension, has close relation to the spatial and temporal variation of the Kuroshio and Oyashio Current.

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열대 태평양에서 운영되는 TRITON 부이와 비교를 통한 KORDI 부이 시스템 개선 연구 (A Study for Improving the KORDI Buoy System in Comparison with TRITON Buoys in the Tropical Pacific Ocean)

  • 김동국;전동철;김응;황근춘;황상철
    • Ocean and Polar Research
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    • 제33권spc3호
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    • pp.359-369
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    • 2011
  • This study documents KORDI's experience of successfully deploying a deep ocean buoy for monitoring oceanic and atmospheric variabilities in the tropical western Pacific Ocea nsince May 2010. The primary focus of this study was to compare TRITON (big and old type) with m-TRITON (smaller and new type) buoys within the JAMSTEC's buoy management system. The objective of operating a KORDI buoy is to ascertain oceanic variability in the tropical western Pacific. We adopted a slack-line mooring type to observe water temperatures at six layers from surface to 400 m depth. However, we could not acquire satisfactory results due to lack of expertise in buoy management system. A new KORDI buoy has been developing, which has been modified from both buoys, and ARGOS-3 satellite system and a slack-type mooring line.

NOAA/AVHRR 정규식생지수의 시공간 변화도 분석 (Analysis of Spatial-temporal Variability of NOAA/AVHRR NDVI in Korea)

  • 김광섭;김종필
    • 대한토목학회논문집
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    • 제30권3B호
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    • pp.295-303
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    • 2010
  • 식생의 변화는 강수, 기온, 유출 등의 수문기상변수들의 변화와 상당히 밀접한 연관성을 가지고 있다. 식생의 변화에 대한 분석은 곧 기후변화의 지역적 영향을 이해하는데 큰 도움이 될 것이다. 따라서 본 연구에서는 우리나라 지역에 대해서 NOAA/AVHRR 정규식생지수(NDVI)의 시공간변화도를 분석하였다. Mann-Kendall 검정을 이용한 연평균 정규식생지수의 추세분석결과는 대상기간(1982년~2006년)동안 대부분의 유역에서 통계적 유의성을 가진 선형적인 추세변화는 없는 것으로 나타났으나, 금강유역에서 통계적 신뢰수준 90%의 하향추세가 있었다. 또한 EOF 분석을 이용한 주성분분석결과 북쪽지역으로 갈수록 표고가 높을수록 식생의 변화도가 큰 것으로 나타났다. 이는 지형변화에 상관성이 높은 연평균 정규식생지수의 공간분포와 달리 위경도 변화에 대응하는 분산분포 변화특성에 기인한 것으로 판단된다. 계절별로는 6월~9월까지의 정규식생지수가 높게 나타났으며, 이 기간 중에서 7월경에 다소 감소하는 경향을 보여주었다. 유역별로는 한강유역의 정규식생지수가 가장 높았으며, 제주도가 가장 낮은 것으로 나타났다.

전구 대양의 극저 해수면온도 공간 분포와 지구과학교과서 데이터 시각화 분석 (Spatial Distribution of Extremely Low Sea-Surface Temperature in the Global Ocean and Analysis of Data Visualization in Earth Science Textbooks)

  • 박경애;손유미
    • 한국지구과학회지
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    • 제41권6호
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    • pp.599-616
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    • 2020
  • 해수면온도는 해양-대기 상호작용, 열속 변화, 대양의 해양 순환을 이해할 수 있는 가장 중요한 해양 변수들 중의 하나이다. 0℃ 이하 -2℃까지 극저 해수면온도는 기후변화 및 지구환경 변화를 유도하고 조절하기 때문에 다른 범위의 해수면온도보다 더 중요하게 다루어져야 한다. 전구 대양에서 이러한 극저 해수면온도의 시간적 공간적 변동성을 이해하기 위하여 1982년부터 2018년까지의 기간 동안 관측된 인공위성 일별 해수면온도 데이터베이스를 활용하여 평균 기후장을 산출하였다. 또한 장기간의 해양 실측 자료에 기반하여 생산된 표층 수온의 기후 평균장을 활용하여 극저 해수면온도가 전구 대양에서 존재하는 해역과 0℃ 등온선의 월별 공간 변동을 분석하였다. 그 결과 극저 해수면온도는 북극해와 남극해와 같은 극지 해역과 고위도의 연해에서 상당한 해양의 표면적을 차지하고 있었다. 이러한 극저 해수면 온도가 어떻게 시각화되어 있는지 검토하기 위하여 6종 지구과학교과서를 분석하였다. 대부분의 교과서에서 해수면온도 삽화는 0℃ 혹은 그 이상 수온에서 부터 도시하여 학생들이 극저 해수면온도에 대한 개념과 역할에 대한 이해를 획득하는 것을 저해하고 있었다. 데이터 시각화는 데이터 리터러시의 주요한 요소 중에 하나이므로 위성 해수면온도 자료가 교과서에 적절하게 시각화되도록 교과서 삽화의 개선이 필요하다. 본 연구는 인공위성 해수면온도 자료와 해양 실측 자료를 활용하여 해양 데이터의 시각화를 통하여 해양학적 소양과 데이터 리터러시가 동시에 함양되고 강화될 수 있음을 강조하였다.

Temporal Variation of the Western Pacific Subtropical High Westward Ridge and its Implicationson South Korean Precipitation in Late Summer

  • Ahn, Kuk-Hyun
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.24-24
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    • 2019
  • This study investigates variations in the Western Pacific Subtropical High (WPSH) and its impact on South Korean precipitation in late summer during the period between 1958 and 2017. Composite analysis reveals that precipitation occurrence is directly linked to the displacement of the WPSH western ridge, a single, large-scale feature of the atmosphere in the Pacific Ocean. When WPSH ridging is located northwest (NW) of its climatological mean position, excessive precipitation is expected in late summer due to enhanced moisture transport. On the other hand, a precipitation deficit is frequently observed when the western ridge is located in the southeast (SE). Different phases of the WPSH are associated with lagged patterns of Pacific and Atlantic atmospheric and oceanic variability, introducing the potential to predict variability in the WPSH western ridge and its climate over northern East Asia by one month. Based on the identified SST patterns, a simple statistical model is developed and improvement in the ability to predict is confirmed through a cross-validation framework. Finally, the potential for further improvements in WPSH-based predictions is addressed.

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