• Title/Summary/Keyword: northwestern Pacific

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Modeling on the North Pacific Ocean

  • Kwangwoo Cho;Yoon, Jong-Hwan;Park, Seog-Won
    • 한국어업기술학회:학술대회논문집
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    • 한국어업기술학회 2000년도 추계수산관련학회 공동학술대회발표요지집
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    • pp.167-168
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    • 2000
  • A North Pacific Ocean Model has been developed with the Global Ocean Model of the Meteorological Research Institute of Japan which solves the primitive equations with Boussinesq, rigid-lid, and hydrostatic assumptions. The objective of the study is to improve the description of the variability on the East Sea and northwestern Pacific Ocean. (omitted)

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엘니뇨/라니냐가 북서태평양 아열대 난수역과 북부동중국해의 중형동물플랑크톤 생체량에 미치는 영향 (Effect of El Niño/Na Niña on Mesozooplankton Biomass in the Northwestern Subtropical Pacific Warm Pool and the Northern East China Sea)

  • 강형구;신창웅;전동철
    • Ocean and Polar Research
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    • 제37권3호
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    • pp.189-200
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    • 2015
  • Mesozooplankton biomass including total biomass and size-fractionated biomass and the abundance of major taxonomic groups of copepods were studied in the Northwestern Subtropical Pacific Warm Pool (NSPWP) and the Northern East China Sea (NECS) from 2006 to 2014. Mesozooplankton biomass ranged from 0.69 to $3.08mgC/m^3$ (mean $1.12mgC/m^3$) in the NSPWP and from 10.60 to $69.10mgC/m^3$ (mean $30.33mgC/m^3$) in the NECS with higher values in spring than fall. Percent composition in the biomass of each size group of mesozooplankton varied interannually both in the NSPWP and in the NECS. The smallest size group (0.2~0.5 mm) contributed the least to total biomass in both regions, but significantly higher in the NSPWP than in the NECS. The percent composition in abundance of copepod taxonomic groups (i.e. Calanoida, Cyclopoida, and Poecilostomatoida) also fluctuated interannually. Mean composition of calanoid copepods was higher in the NECS than in the NSPWP, but the opposite pattern was observed for poecilostomatoid copepods. Mesozooplankton biomass both in the NSPWP and in the NECS was negatively correlated with Oceanic $Ni{\tilde{n}}o$ Index (ONI), indicating declines in biomass during El $Ni{\tilde{n}}o$ periods and vice versa during Na $Ni{\tilde{n}}a$ period. The effect of El $Ni{\tilde{n}}o$ on variation of mesozooplankton biomass was more prominent in the NSPWP than in the NECS. These results suggest that mesozooplankton biomass both in the NSPWP and in the NECS responded to El $Ni{\tilde{n}}o$ events, although the biological process that explain the reduced mesozooplankton biomass might be different in both regions.

ROMS-NPZD 접합모델을 이용한 한반도 주변해역의 표층 영양염 및 클로로필의 계절변동성 (Application of ROMS-NPZD Coupled Model for Seasonal Variability of Nutrient and Chlorophyll at Surface Layer in the Northwestern Pacific)

  • 이준호;김태훈;문재홍
    • Ocean and Polar Research
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    • 제38권1호
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    • pp.1-19
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    • 2016
  • Recently, there has been a growing interest in physical-biological ocean-modeling systems by communities in the fields of science and business. In this paper, we present preliminary results from a coupled physical-biological model for the Northwestern Pacific marginal seas. The ocean circulation component is an implementation of the Regional Ocean Modeling System (ROMS), and the lower trophic level ecosystem component is a Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD) model. The ROMS-NPZD coupled system, with a 25 km resolution, is forced by climatological atmospheric data and predicts the physical variables and concentrations of nitrate, phytoplankton, zooplankton, and detritus. Model results are compared with remote-sensed sea surface temperature and chlorophyll, and with climatological sea surface salinity and nitrate. Our model adequately reproduces the observed spatial distribution and seasonal variability of nitrate and chlorophyll concentrations as well as physical variables, showing a high correlation in the East Sea (ES) and Kuroshio/Oyashio Extension (KOE) region but relatively low correlation in the Yellow Sea (YS) and East China Sea (ECS). Although some deficiencies were found in the biological components, such as the over/underestimation of the intensity of phytoplankton blooms in the ES and KOE/the YS and ECS, our system demonstrates the capability of the model to capture and record dominant seasonal variability in physical-biological processes and this holds out the promise of coming to a better understanding of such processes and making better predictions .

한국 여름가뭄과 북서태평양 태풍활동의 연관성 (Relationships between Summer Droughts in Korea and Activities of Tropical Cyclones over the Northwestern Pacific)

  • 최기선;김도우;변희룡
    • 대기
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    • 제18권4호
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    • pp.279-286
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    • 2008
  • In the tropical western Pacific (especially, west of 135oE, including South China Sea and the Philippines), during boreal summer, it was found that a strong correlation exists between the tropical cyclone activity and the drought conditions in Korea. During the summer drought, firstly, there were strong ascending flows over the tropical western Pacific with more tropical cyclone genesis, and to compensate for this, descending flows develop in the mid-latitudes, thereby causing drought; in other words, a secondary circulation is formed between the tropical western Pacific and mid-latitudes of East Asia. Secondly, the developments of both the subtropical western Pacific high and the Manchurian low are suppressed. As a result, both the land-sea pressure gradient and the southerly flow from low-latitudes to Korean area are also weakened, which reduces approaches of tropical cyclones to this area despite the high frequency of their geneses.

Development of High-Resolution Pacific Ocean Circulation Model

  • You Sung-Hyup;Yoon Jong-Hwan;Seo Jang-Won;Youn Yong-Hoon
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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    • pp.129-132
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    • 2006
  • A Pacific Ocean circulation model based on the RIAM Ocean Model (RIAMOM) with $1/6^{\circ}C\;and\;1/12^{\circ}C$ horizontal resolution successfully reproduced the peculiar circulation structures of the Pacific Ocean. The volume transports of model agree very well with the results of observations in the northwestern Pacific Ocean. Also our model successfully reproduced the observed structures of the northeastward Ryukyu Current with a subsurface core at $500{\sim}600m$. A Possible mechanism for the subsurface current core of the Ryukyu Current is proposed focusing on the blocking effect of the Ryukyu Island Chain.

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북서태평양 황제해산해역 저어류의 종조성 및 자원밀도 (Species Composition and Density of the Demersal Fishes on the Emperor Seamount in the Northwestern Pacific Ocean)

  • 권유정;황선도;김영승;문대연
    • 한국어류학회지
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    • 제21권2호
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    • pp.118-124
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    • 2009
  • 2005년부터 2007년까지 북서태평양 황제해산해역에서 한국 트롤어업에 의해 어획된 어획 자료를 수집하여 어류종조성과 생물량의 시 공간 변동을 분석하였다. 어획량은 2005년에 750 mt, 2006년에 460 mt, 2007년에 440 mt로 어획되었다. 2005년부터 2007년까지 어획된 북서태평양 황제해산해역의 우점종은 빛금눈돔(Beryx splendens) 및 민사자구(Pseudopentaceros wheeleri)이었다. 직접자원량추정법인 소해면적법(swept area method)를 이용하여 빛금눈돔과 민사자구의 2005~2007년 동안 3년간 평균 생물량은 각각 791 mt과 266 mt로 추정되었다.

Development of a Probability Prediction Model for Tropical Cyclone Genesis in the Northwestern Pacific using the Logistic Regression Method

  • Choi, Ki-Seon;Kang, Ki-Ryong;Kim, Do-Woo;Kim, Tae-Ryong
    • 한국지구과학회지
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    • 제31권5호
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    • pp.454-464
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    • 2010
  • A probability prediction model for tropical cyclone (TC) genesis in the Northwestern Pacific area was developed using the logistic regression method. Total five predictors were used in this model: the lower-level relative vorticity, vertical wind shear, mid-level relative humidity, upper-level equivalent potential temperature, and sea surface temperature (SST). The values for four predictors except for SST were obtained from difference of spatial-averaged value between May and January, and the time average of Ni$\tilde{n}$o-3.4 index from February to April was used to see the SST effect. As a result of prediction for the TC genesis frequency from June to December during 1951 to 2007, the model was capable of predicting that 21 (22) years had higher (lower) frequency than the normal year. The analysis of real data indicated that the number of year with the higher (lower) frequency of TC genesis was 28 (29). The overall predictability was about 75%, and the model reliability was also verified statistically through the cross validation analysis method.

Sex-related Differences in DNA Copy Number Alterations in Hepatitis B Virus-Associated Hepatocellular Carcinoma

  • Zhu, Zhong-Zheng;Wang, Dong;Cong, Wen-Ming;Jiang, Hongmei;Yu, Yue;Wen, Bing-Ji;Dong, Hui;Zhang, Xiao;Liu, Shu-Fang;Wang, Ai-Zhong;Zhu, Guanshan;Hou, Lifang
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권1호
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    • pp.225-229
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    • 2012
  • Background: Males have a higher prevalence of hepatocellular carcinoma (HCC) than females in general, but the reasons for the sex disparity are still obscure. DNA copy number alteration (CNA) is a major feature of solid tumors including HCC, but whether CNA plays a role in sex-related differences in HCC development has never been evaluated. Methods: High-resolution array comparative genomic hybridization (CGH) was used to examine 17 female and 46 male HCC patients with chronic hepatitis B virus (HBV) infection in Shanghai, China. Two-tailed Fisher's exact or ${\chi}^2$ tests was used to compare CNAs between females and males. Results: The overall frequencies and patterns of CNAs in female and male cases were similar. However, female HCC tumors presented more copy number gains compared to those in males on 1q21.3-q22 (76.5% vs. 37.0%, P = 0.009), 11q11 (35.3% vs. 0.0%, P = 0.0002) and 19q13.31-q13.32 (23.5% vs. 0.0%, P = 0.004), and loss on 16p11.2 (35.3% vs. 6.5%, P = 0.009). Relative to females, male cases had greater copy number loss on 11q11 (63.0% vs. 17.6%, P = 0.002). Further analyses showed that 11q11 gain correlated with 19q13.31-q13.32 gain (P = 0.042), 11q11 loss (P = 0.011) and 16p11.2 loss (P = 0.033), while 1q21.3-q22 gain correlated with 19q13.31-q13.32 gain (P = 0.046). Conclusions: These findings suggest that CNAs may play a role in sex-related differences in HBVassociated HCC development.

북서태평양 아열대 해역에서 침강입자 플럭스의 시·공간 변동 (Temporal and Spatial Variations of Sinking-particle Fluxes in the Northwestern Subtropical Pacific)

  • 김형직;형기성;유찬민;전동철;정진현;김부근;김동선
    • Ocean and Polar Research
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    • 제33권spc3호
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    • pp.385-395
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    • 2011
  • Time-series sediment traps were deployed at 1,000 m water depth of the northwestern subtropical Pacific from July 2009 to June 2010, with the aim of understanding temporal and spatial variations of sinking-particle fluxes. The opening and closing of the traps was synchronized at 18-day periods for 20 events. Total mass fluxes showed distinct seasonal variations with high values for the summer-fall seasons and relatively low values for winter-spring. This seasonal variation at two stations was characterized by a distinct difference in $CaCO_3$ fluxes between the two seasons. The enhanced $CaCO_3$ flux in the summer - fall seasons might be attributed to an increased planktonic foraminiferal flux. Total mass flux at FM10 station was nearly 50% higher than that at FM1 station. The difference in $CaCO_3$ fluxes between two stations contributed nearly 70% of the difference of total mass fluxes. The $CaCO_3$ flux was a major component controlling temporal and spatial variation of sinking - particle fluxes in the western subtropical Pacific Ocean.

TIME SERIES ANALYSIS USING GRIDDED WIND-STRESS PRODUCT DERIVED FROM SATELLITE SCATTEROMETER DATA

  • KUTSUWADA KUNIO;MORIMOTO NAOKI
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.52-53
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    • 2005
  • Time series of gridded surface wind and wind-stress vectors over the world ocean have been constructed by satellite scatterometer data. The products are derived from the ERS-l,2 covering 9 years during 1992-2000 and the Sea Winds on board QuikSCAT (Qscat) which has been operating up to the present since June 1999, so they allows us to analyze variabilities with various time scales. In this study, we focus on interannual variability of the wind stress in the mid- and high-latitude region of North Pacific. These are compared with those by numerical weather prediction(NWP) ones (NCEP Reanalysis). We also examine variability in the wind-stress curl field that is an important factor for ocean dynamics and focus its time and spatial characters in the northwestern Pacific around Japan. It is found that the vorticity field in the lower atmosphere tends to increase gradually with time, suggesting the enhancement of the North Pacific subtropical gyre.

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