• Title/Summary/Keyword: Pacific sea level

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Mechanism Study of Tropical Cyclone Impact on East Asian Subtropical Upper-Level Jet: a Numerical Case Investigation

  • Chen, Xian;Zhong, Zhong;Lu, Wei
    • Asia-Pacific Journal of Atmospheric Sciences
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    • v.54 no.4
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    • pp.575-585
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    • 2018
  • In the case study of this paper, sensitivity experiments are carried out using the mesoscale non-hydrostatic Weather Research and Forecasting (WRF) model to investigate the impact of tropical cyclone (TC) Soudelor (2003) on the East Asian subtropical upper-level jet (EASJ) before TC Soudelor transformed into an extratropical cyclone. The physical mechanism for changes in the EASJ intensity and position caused by TC Soudelor is explored. Results indicate that TC Soudelor would warm the air in the middle and upper troposphere over the Japan Sea and the adjacent areas through stimulating northward propagating teleconnection pattern as well as releasing large amounts of latent heat, which led to increase (decrease) the meridional air temperature gradient to the south (north) below the EASJ axis. As a result, the geopotential height abnormally increased in the upper troposphere, resulting in an anomalous anticyclonic circulation belt along the EASJ axis. Correspondingly, the westerly winds to the north (south) of the EASJ axis intensified (weakened) and the EASJ axis shifted northward by one degree. The case study also suggests that before the extratropical cyclone transition of TC Soudelor, the TC activities had exerted significant impacts on the EASJ through thermodynamic processes.

A Statistical Analysis for El Nino Phenomenon (엘니뇨현상에 대한 통계적분석)

  • 김해경
    • 한국해양학회지
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    • v.27 no.1
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    • pp.35-45
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    • 1992
  • This paper is concerned with the development and application of a stochastic model for predicting E1 nino phenomenon. For this, first a general criterion for determining E1 nino phenomenon, including period and strength, which is based on partial sum of monthly sea surface temperatures (SST) anomalies, is proposed, Secondly, the annual fluctuations, periodicity and dependence of monthly mean of equatorial Pacific SST during the period 1951-1990 are analyzed. Based on these, time series nonlinear regression model for the prediction of SST have been derived. A statistical procedure for using the model to predict the SST have been derived. A statistical procedure for using the model to predict the SST level is also proposed.

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Spatial Distribution and Community Structure of Macrobenthos on the Sandy Shore of Anmyeondo, Korea (안면도 사질 조간대에 서식하는 대형저서동물의 공간분포 및 군집구조)

  • Jung, Yun-Hwan;Yoon, Kon-Tak;Park, Heung-Sik;Ma, Chae-Woo
    • Ocean and Polar Research
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    • v.35 no.1
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    • pp.27-37
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    • 2013
  • The western coast of Anmyeondo is open toward the Yellow sea and the northern and southern coasts are sandy and have simple coastlines. In this study, we investigated the spatial distribution and community structure of the macrobenthos that inhabit the sandy shore of Anmyeondo. For the study, we chose 8 sites encompassing 44 stations. In total, we have recorded 62 species, and collected 747 inds./$m^2$ on average. Zonation pattern did not appear because the mean grain size and organic contents of the study sites were similar among the macrobenthos. Polychaetes were most frequently recorded, but amphipods appeared in higher mean density. Macrobenthic community is classified into 3 groups largely based on the density difference among the dominant species and the groups were not influenced by environmental factors. The aggregated distribution of macrobenthos did not show a clear regional spatial difference but exhibited classification pattern emphasizing the density difference of the dominant species. The sandy shores of Anmyeondo are relatively more influenced by waves compared to other regions and the sediment moves more due to strong winds, etc. at low tide. We presume that the movement of sediment resulted in a relatively even sedimentary environment and consequently weakened environmental variables that change with the tide level. We concluded that the macrobenthic community does not show the zonation pattern in the sandy shores of Anmyeondo due to such influences.

Decadal Change in Rainfall During the Changma Period in Early-2000s (2000년대 초반 우리나라 장마기간 강수량의 십년 변화 특성)

  • Woo, Sung-Ho;Yim, So-Young;Kwon, Min-Ho;Kim, Dong-Joon
    • Atmosphere
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    • v.27 no.3
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    • pp.345-358
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    • 2017
  • The decadal change in rainfall for Changma period over the South Korea in early-2000s is detected in this study. The Changma rainfall in P1 (1992~2002) decade is remarkably less than in P2 (2003~2013) decade. The much rainfall in P2 decade is associated with the increase of rainy day frequency during Changma period, including the frequent occurrences of rainy day with a intensity of 30 mm/day or more in P2 decade. This decadal change in the Changma rainfall is due to the decadal change of atmospheric circulation around the Korean Peninsula which affects the intensity and location of Changma rainfall. During P2 decade, the anomalous anti-cyclone over the south of the Korean Peninsula, which represents the expansion of the North Pacific high with warm and wet air mass toward East Asia, is stronger than in P1 decade. In addition, the upper level zonal wind and meridional gradient of low-level equivalent potential temperature in P2 decade is relatively strengthened over the northern part of the Korean Peninsula than in P1 decade, which corresponds with the intensification of meridional gradient between air mass related to the East Asian summer monsoon nearby the Korean Peninsula in P2 decade. The enhanced meridional gradient of atir mass during P2 decade is favorable condition for the intensification of Changma rainfall band and more Changma rainfall. The atmospheric conditions related to enhanced Changma rainfall during P2 decade is likely to be influenced by the teleconnection linked to the suppressed convection anomaly over the southern part of China and South China Sea in P2 decade.

Effects of Breast Cancer Fatalism on Breast Cancer Awareness among Nursing Students in Turkey

  • Kulakci, Hulya;Ayyildiz, Tulay Kuzlu;Yildirim, Nuriye;Ozturk, Ozlem;Topan, Aysel Kose;Tasdemir, Nurten
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3565-3572
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    • 2015
  • Background: Breast cancer is the most common cancer among women and leading cause of death worldwide, including in Turkey. High perceptions of cancer fatalism are associated with lower rates of participation in screening for breast cancer. This study was conducted to evaluate the effect of breast cancer fatalism and other factors on breast cancer awareness among nursing students in Turkey. Materials and Methods: This cross-sectional descriptive study was conducted at three universities in the Western Black Sea region. The sample was composed of 838 nursing students. Data were collected by Personal Information Form, Powe Fatalism Inventory (PFI) and Champion's Health Belief Model Scale (CHBMS). Results: Breast cancer fatalism perception of the students was at a low level. It was determined that students; seriousness perception was moderate, health motivation, BSE benefits and BSE self-efficacy perceptions were high, and BSE barriers and sensitivity perceptions were low. In addition, it was determined that students awareness of breast cancer was affected by breast cancer fatalism, class level, family history of breast cancer, knowledge on BSE, source of information on BSE, frequency of BSE performing, having breast examination by a healthcare professional within the last year and their health beliefs. Conclusions: In promoting breast cancer early diagnosis behaviour, it is recommended to evaluate fatalism perceptions and health beliefs of the students and to arrange training programs for this purpose.

Synoptic Climotological Characteristics of Winter Droughts in Korea (한국의 동계한발의 종관기후학적 특성)

  • Yang, Jin-Suk
    • Journal of the Korean association of regional geographers
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    • v.11 no.4
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    • pp.429-439
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    • 2005
  • The propose of this study is to identify distributional characteristics of winter droughts through occurrence frequencies and to analyze synoptic characteristics on the sea level pressure fields and 500hPa levels in Korea. The regional distributions of winter droughts in occurrence frequency vary according to the monthly regional distributions of the variabilities of precipitation in Korea. In January and December, the eastern parts of Korea where the variabilities of precipitation show high, have high rate of drought frequencies, while the western parts have low rate of it. It means that the regional distribution of the drought frequencies in January and December shows the east-high and west-low pattern, In February the frequencies show the north-high and south-low pattern. In the distributions of the sea-level pressure and 500hPa level height anomalies, the positive anomalies appear around Korean Peninsula and Siberian high area, the negative anomalies on the Aleutian low area and the western parts of North Pacific Ocean during the drought period in January and February. The droughts appear when the inflow of warm and humid air from the south eastern parts blocked by the prevailing pressure patterns of the west-high and east-low. Therefore, the zonal wind of the Korean Peninsula is strong. The droughts of December reflect not only low frequencies of cyclone occurrence, also small inflow of warm and humid air from the southern parts stemming from positive anomalies over whole middle latitude of eastern parts of Asia including Korean Peninsula.

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Wind Castle: The Natural Intelligence Control of Hallasan-Oreum-Batdam I (윈드캐슬: 한라산-오름-밭담의 자연지능 제어 I)

  • Lee, Moon-Ho;Kim, Jeong-Su
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.3
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    • pp.105-111
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    • 2020
  • We defined Jeju Wind Castle and analyzed the relationship between Hallasan-Oreum-Batdam, the main subject, for the first time. In Jeju, 1.5m high Batdam(Black Silk Road), 368 Oreums, Hallasan Mountain 1950m are all unique scenery. The verification of this paper demonstrates that Samdasoo's groundwater extraction sea level is equal to the height of Hallasan and that this problem is mathematically complete in neutral plane theory. Donnaeko(700meters above sea level)-Baeknokdamdongneung-Jindallebat-Seongpanak-Gyorae(453 meters)-Witsaeoreum(1700meters) is a rain belt that hits the low-air pressure air-conditioned North Pacific humidity rising from the southeast and the high-pressure cold air of Hallasan Peak. It rains a lot because - and + are neutral plane, which adds to zero. Hallasan is called Jinsan in Jeju history. The answer is Wind Castle. The number of Oreum in Jeju is 369 including Hallasan, and Batdam, which is about 1.5m high, does not collapse even with a typhoon blowing over 50m/s. Because the wind castle's core is 1.5 meters of Batdam and it is a triangular number.

A Review on Multidecadal Coastal Changes at Funafuti, Tuvalu from 1897 to 2015

  • Ahmed, Harun-Al-Rashid;Chan-Su, Yang
    • Korean Journal of Remote Sensing
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    • v.39 no.1
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    • pp.23-45
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    • 2023
  • Tuvalu is a small reef islands country in the Pacific Ocean. Its coastal regions are very much dynamic due to the profound effects of tropical cyclones and sea level rise (SLR). However, research works on coastline dynamics of Tuvalu mainly cover its capital, Funafuti. Therefore, this review summarizes the extent of long-term coastal changes in different islets of Funafuti and on overall Tuvalu. In Funafuti, highly accreting areas are Te Afualiku, Fuafatu, Motugie, and Amatuku, and highly eroding areas are Fuagea and Tefala with the fully disappeared islet of Vasafua after 2005. However, in spite of different causes and supposition of scientists on disappearing these lands the accretion is more dominant than erosion which resulted in 7.3% net increase of land areas of Tuvalu over 117 years till 2015. Severe tropical cyclones mainly caused accretion of land areas by forming coral rubble rampart formation and further reworks and erosion to small sandy islands whereas frequent low-energy cyclones mainly caused erosion. Though, till now severe erosion of coastal areas are not evident by global SLR, islets of Funafuti experienced remarkable shoreline increase as formation of 30-40 m wide rubble rampart formation along 19 km in 1971 by tropical cyclone Bebe and net increase of area of 3.45 ha by tropical cyclone Pam in 2015. In spite of such overall accretion of coastal areas several scientists suspect drowning of its areas in future because of high SLR (~5.1±0.7 mm/year) at Funafuti which supposedly will not work as a breakwater anymore. Thus, protection measures should be taken to prevent coastline erosion as well as land reclamation activities should be done following the global examples.

Assessment of fishing power and fishing capacity of the snow crab (Chionoecetes opilio) gillnet fishery in the East Sea (동해안 대게 자망어업의 어획 성능 및 어획 능력 평가)

  • Lee, Kyoung-Hoon;Kim, Pyung-Kwan;Kim, Do-Hoon;An, Heui-Chun;Lee, Chun-Woo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.1
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    • pp.29-39
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    • 2012
  • Currently, environment-friendly and sustainable fisheries are one of the major issues among fisheries authorities. A variety of alternative management policies and projects are going on to enhance fisheries management systems and fishery resources such as a TAC management program and a VDS (Vessel Day Scheme) management scheme for distant water fishing nations in Western and Central Pacific Fisheries Commission (WCPFC) convention area. These kinds of efforts among fisheries management authorities are aimed at limiting fishing capacity or fishing power. In terms of fisheries management, Fishing capacity and fishing power have increased the importance of the impact on a fishery and level of the resources. Increased fishing capacity and fishing power have caused not only depletion of fisheries resource, but also additional fishing cost. therefore, there is a clear need for authorities to manage fishing capacity and fishing power. It is also help ensure the conservation and sustainability of the fishery resources. Because of lack of data, absolute fishing power is difficulty to measure. The notion of relative fishing power is frequently used. In this study, relative fishing power was assessed using Mastuda (1991) method for fishing power index. The raw data for assessment was based on fishermen's logbook data from sampled fishing vessels in coastal snow crab gillnet fishery. Data Envelopment Analysis (DEA) method was used to assess fishing capacity. DEA is a linear programming methodology to measure the efficiency of a set of entities called Decision-Making Units (DMUs). It was recommended by FAO for assessing capacity in fisheries.

The Influence of Environmental Characteristics on the Fatness of Pacific Oyster, Crassostrea gigas, in Hansan-Koje Bay (한산${\cdot}$거제만의 환경특성이 양식 굴의 비만에 미치는 영향)

  • CHOI Woo-Jeung;CHUN Yong-Yull;PARK Jeung-Hum;PARK Yeong-Chull
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.5
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    • pp.794-803
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    • 1997
  • Long line suspended culture of oysters has been started commercially in Hansan-Koje Bay since 1969. However, its Annual production has been decreased and culturing periods extended in recent years. So, we investigated environmental parameters and food organisms to identity the causes of poor fatness of oysters in Hansan-Koje Bay from February to November, 1994. As the result, the Water quality of Hansan-Koje Bay was found to be good for culture. For example, the mean concentration of COD was $1.35mg/\ell$, phosphate phosphorus was $0.30{\mu}g-at/\ell$ and dissolved inorganic nitrogen was $4.68{\mu}g-at/\ell$. However, the Hwado island and the inner part of the Hansan-Koje Bay were found to be eutrophicated due to various contaminants transported by land-based activities. But in the central pan of the Hansan-Koje Bay where the oyster farms Have been developed densely, the level of nutrient concentration was very low. During the study period, the dominant species of phytoplankton was Chaetoceros spp. with the percentage of $72.6\%\~87.8\%$ and the mean values of Chlorophyll-a concentration and phytoplankton standing crops were $2.05mg/m^3\;and\;188ind./m\ell$, respectively. The distribution of these parameters also showed similar trends those of nutrients. Especially, chlorophyll-a contents was very low with the concentration of below $0.5mg/m^3$ at central part of the Bay, Juklimpo. The fatness of oysters and the eutrophic index in this area were $18.1\%$ and 0.54, respectively. These values were lower than those of other culturing farms in the southern coastal areas in Korea. Therefore, we estimated that the insufficient food supply due to the low level of nutritional status was the major factors affecting the poor fatness of the Pacific oysters in Hansan-Koje Bay.

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