• Title/Summary/Keyword: north pacific high

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A Study on Sensitivity of Heavy Precipitation to Domain Size with a Regional Numerical Weather Prediction Model (지역예측모델 영역 크기에 따른 집중호우 수치모의 민감도 실험)

  • Min, Jae-Sik;Roh, Joon-Woo;Jee, Joon-Bum;Kim, Sangil
    • Atmosphere
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    • v.26 no.1
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    • pp.85-95
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    • 2016
  • In this study, we investigated the variabilities of wind speed of 850 hPa and precipitable water over the East Asia region using the NCEP Final Analysis data from December 2001 to November 2011. A large variance of wind speed was observed in northern and eastern China during the winter period. During summer, the regions of the East China Sea, the South Sea of Japan and the East Sea show large variances in the wind speed caused by an extended North Pacific High and typhoon activities. The large variances in the wind speed in the regions are shown to be correlated with the inter-annual variability of precipitable water over the inland region of windward side of the Korean Peninsula. Based on the investigation, sensitivity tests to the domain size were performed using the WRF model version 3.6 for heavy precipitation events over the Korean Peninsula for 26 and 27 July 2011. Numerical experiments of different domain sizes were set up with 5 km horizontal and 50 levels vertical resolutions for the control and the first experimental run, and 9 km horizontal for the second experimental run. We found that the major rainfalls correspond to shortwave troughs with baroclinic structure over Northeast China and extended North Pacific High. The correlation analysis between the observation and experiments for 1-h precipitation indicated that the second experiment with the largest domain had the best performance with the correlation coefficient of 0.79 due to the synoptic-scale systems such as short-wave troughs and North Pacific High.

Characteristics of 1994-95 Summer Monsoon Inferred from SSM/I-derived Water Budget Parameters (SSM/I 대기물수지 변수를 이용한 1994-95년 하계 몬순의 특성 연구)

  • 손병주;김도형;김혜영;서애숙
    • Korean Journal of Remote Sensing
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    • v.14 no.1
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    • pp.1-16
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    • 1998
  • Microwave brightness temperature data measured from the Special Sensor Microwave/Imager (SSM/I) aboard Defense Meteorological Satellite Program (DMSP) satellite are used to investigate the characteristics of hydrological features of the East Asian summer monsoon during 1994 and 1995. The analyzed parameters include total columnar water vapor, cloud liquid water, and rain rate. These are estimated from SSM/I brightness temperature data for the two summer seasons (June, July, August) of 1994 and 1995 over the Asian monsoon region (0$^{\circ}$-60$^{\circ}$N, 45$^{\circ}$-180$^{\circ}$E). Results indicate that there are periodic westward movement of dry air over the 20$^{\circ}$-30$^{\circ}$N latitudinal belt with about 20-30 day period. Considering that the location of the North Pacific high is closely linked to the evolution of the monsoon activities over East Asia, the westward expansion of the North Pacific high may be the one important element modulating the monsoon intensity.

Hydrographic Structure Along 131.5°W in the Eastern Tropical Pacific in July 2003

  • Chang, Kyung-Il;Hwang, Sang-Chul;Hong, Chang-Su
    • Ocean and Polar Research
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    • v.26 no.2
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    • pp.299-309
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    • 2004
  • Conductivity-temperature-depth (CTD) data obtained along a meridional section in the eastern tropical Pacific in July 2003 have been analyzed to identify various water masses, and to examine the hydrographic structure and zonal geostrophic currents in the upper 1000 m. Water mass analysis shows the existence of subtropical and intermediate waters, characterized by layers of subsurface salinity maximum and minimum, originating from both hemispheres of the Pacific. Vertical section of temperature in the upper 200 m shows the typical trough-ridge structure associated with the zonal current system for most of the tropical Pacific. Water with the lowest salinity of less than 33.6 was found in the upper 30 m between $8.5^{\circ}N$ and $10.5^{\circ}N$ in a boundary zone between the North Equatorial Current and North Equatorial Countercurrent. Temporal changes in water properties observed at $10.5^{\circ}N$ over a period of 9 days suggest both the local rainfall and horizontal advection is responsible for the presence of the low-salinity water. Development of a barrier layer was also observed at $10.5^{\circ}N$. In the North Equatorial Current region a local upwelling was observed at $15^{\circ}N$, which brings high salinity and cooler subtropical water to the sea surface. A band of countercurrent occurs in the upwelling region between $13^{\circ}N$ and $15^{\circ}N$.

High Temperature of Food and Beverage Intake Increases the Risk of Oesophageal Cancer in Xinjiang, China

  • Tang, Li;Xu, Fenglian;Zhang, Taotao;Lei, Jun;Binns, Colin William;Lee, Andy Ho-Won
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5085-5088
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    • 2013
  • Background: The north-western region of China has a high incidence of oesophageal cancer. This study aimed to investigate whether the intake of food and beverage at high temperature is associated with the risk of oesophageal cancer among adults residing in this remote part of China. Materials and Methods: A case-control study was undertaken in Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China, between 2008 and 2009. Participants were 359 incident oesophageal cancer patients and 380 hospital-based controls. Information on temperature of food and beverage intake was obtained by face-to-face interview. Logistic regression analyses were performed to ascertain the association between intake temperature and the risk of oesophageal cancer. Results: The oesophageal cancer patients consumed foods and beverages at higher temperatures than controls, p<0.001. High temperature of tea, water and food intake appeared to increase the risk of oesophageal cancer by more than two-fold, with adjusted odds ratio (95% confidence intervals) of 2.86 (1.73-4.72), 2.82 (1.78-4.47) and 2.26 (1.49-3.45), respectively. Conclusions: Intake of food and beverage at high temperature was positively associated with the incidence of oesophageal cancer in north-western China.

Validation of Satellite Altimeter-Observed Significant Wave Height in the North Pacific and North Atlantic Ocean (1992-2016) (북태평양과 북대서양에서의 위성 고도계 관측 유의파고 검증 (1992-2016))

  • Hye-Jin Woo;Kyung-Ae Park
    • Journal of the Korean earth science society
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    • v.44 no.2
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    • pp.135-147
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    • 2023
  • Satellite-observed significant wave heights (SWHs), which are widely used to understand the response of the ocean to climate change, require long-term and continuous validation. This study examines the accuracy and error characteristics of SWH observed by nine satellite altimeters in the North Pacific and North Atlantic Ocean for 25 years (1992-2016). A total of 137,929 matchups were generated to compare altimeter-observed SWH and in-situ measurements. The altimeter SWH showed a bias of 0.03 m and a root mean square error (RMSE) of 0.27 m, indicating relatively high accuracy in the North Pacific and North Atlantic Ocean. However, the spatial distribution of altimeter SWH errors showed notable differences. To better understand the error characteristics of altimeter-observed SWH, errors were analyzed with respect to in-situ SWH, time, latitude, and distance from the coast. Overestimation of SWH was observed in most satellite altimeters when in-situ SWH was low, while underestimation was observed when in-situ SWH was high. The errors of altimeter-observed SWH varied seasonally, with an increase during winter and a decrease during summer, and the variability of errors increased at higher latitudes. The RMSEs showed high accuracy of less than 0.3 m in the open ocean more than 100 km from the coast, while errors significantly increased to more than 0.5 m in coastal regions less than 15 km. These findings underscore the need for caution when analyzing the spatio-temporal variability of SWH in the global and regional oceans using satellite altimeter data.

Synoptic Climatological Characteristics of Distribution of Precipitation in Korea in Early Autumn (한국의 초가을 강수분포의 종관기후학적 특성)

  • Yang, Jin-Suk
    • Journal of the Korean association of regional geographers
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    • v.5 no.1
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    • pp.151-162
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    • 1999
  • This study is a comparative analysis of sea level and 500hPa surfaces between dry year and wet year, which are selected by variability of precipitation and standardized anomalies in Korea in early autumn. While the amount of precipitation of early autumn decreases, the variability of precipitation increases rapidly reflecting the strength and weakness of Kaul Changma front and the occurrences of the typhoonic precipitation. The regional distribution of the variability of precipitation shows west-high, east-low pattern in which the east coast and the southeastern coast shows low, but high in the southwestern coast. In the anomalies distribution of sea-level and 500hPa surfaces, during dry year, the northern part of Siberia and the core area of North Pacific high shows negative anomalies, on the contrary, there were positive anomalies in wet year at the same areas. In addition, at the 500hPa level, while the Korean peninsula was located at the west of deep trough with low zonal index in dry year, the peninsula was influenced by weak trough with high zonal index showing strong zonal flow in wet year. During dry year the height of 500hPa surface is low at the north of $40^{\circ}N$, but high in wet year. In consequences, this study identified that the occurrences of dry year and wet year were influenced by the seasonal variations of the strength and the weakness of North Pacific high and Siberian high.

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Possible Influence of Western North Pacific Monsoon on Tropical Cyclone Activity Around Korea (북서태평양 몬순이 한국 영향태풍활동에 미치는 영향)

  • Choi, Ki-Seon;Park, Ki-Jun;Lee, Kyungmi;Kim, Jeoung-Yun;Kim, Baek-Jo
    • Journal of the Korean earth science society
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    • v.36 no.1
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    • pp.68-81
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    • 2015
  • In this study, the correlation between the frequency of summer tropical cyclones (TC) affecting areas around Korea over the last 37 years and the western North Pacific monsoon index (WNPMI) was analyzed. A clear positive correlation existed between the two variables, and this high positive correlation remained unchanged even when excluding El Ni$\tilde{n}$o-Southern Oscillation (ENSO) years. To investigate the causes of the positive correlation between these two variables, ENSO years were excluded, after which the 8 years with the highest WNPMI (positive WNPMI phase) and the 8 years with the lowest WNPMI (negative WNPMI phase) were selected, and the average difference between the two phases was analyzed. In the positive WNPMI phase, TCs usually occurred in the eastern waters of the tropical and subtropical western North Pacific, and tended to pass the East China Sea on their way north toward Korea and Japan. In the negative WNPMI phase, TCs usually occurred in the western waters of the tropical and subtropical western North Pacific, and tended to pass the South China Sea on their way west toward the southeastern Chinese coast and the Indochina peninsula. Therefore, TC intensity was higher in the positive WNPMI phase, during which TCs are able to gain sufficient energy from the sea while moving a long distance to areas nearby Korea. TCs also tended to occur more often in the positive WNPMI phase. In the difference between the two phases regarding 850 and 500 hPa streamline, anomalous cyclones were reinforced in the tropical and subtropical western North Pacific, while anomalous anticyclones were reinforced in mid-latitude East Asian areas. Due to these two anomalous pressure systems, anomalous southeasterlies developed in areas near Korea, with these anomalous southeasterlies playing the role of anomalous steering flows making the TCs head toward areas near Korea. Also, due to the anomalous cyclones developed in the tropical and subtropical western North Pacific, more TCs could occur in the positive WNPMI phase.

A Study on the Application of International Law through Disputes Settlement in Northeast Asia Fishing Ground (동북아 어장에서의 어업분쟁 해결 사례를 통한 국제법 적용 방안)

  • Lee, Woo-Do;Kim, Nam-Soo;Lee, Jin-Soo
    • The Journal of Fisheries Business Administration
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    • v.48 no.3
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    • pp.15-32
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    • 2017
  • This article's aim is to review the jurisprudence which has emerged pursuant to the international dispute settlement provisions and to provide a provisional expectation as to the future of international dispute settlement under "UNCLOS". Globally, marine fisheries play an important role in ocean biodiversity and the food security of millions of people, providing a vital source of high-quality dietary protein and supporting individuals' livelihoods and income. In the 1982 Convention, the establishment of co-operative mechanisms for effective monitoring, control, surveillance and enforcement, decision-making procedures facilitating the adoption of such measures of conservation and management, and the promotion of the peaceful settlement of disputes are called for. In this study, 'Northeast Asian Sea' means that the Yellow/East China Sea, the East Sea, the Ohotsk Sea, the Kamchaka Sea, the Alaska Sea, and the Bering Sea surrounded by Korea, China, Japan, Russia, U.S.A. and Canada including their EEZs. There are several bilateral fisheries agreements existing in Northeast Asian area, the Fisheries Agreement between Republic Korea and Japan, between Republic of Korea and China, between China and Japan, between Republic Korea and U.S.A., between Republic Korea and Russia, between Russia and Japan, And there are several regional fisheries organizations existing in Northeast Asian area, for example NPAFC(Convention for the Conservation of Anadromous Stocks in the North Pacific Ocean), CBSPC (Convention on the Central Bering Sea Pollack Conservation), PICES(North Pacific Marine Science Organization), NPFC(North Pacific Fishery Commi-ssion) etc. It analyzed the proliferation of bilateral treaties and multilateral treaties due to the adoption of the EEZ in Northeast Asia reviewed the strengthening of management rights on the high seas marine living resources and marine environment preservation of regional fisheries organizations. In view of the changes in the international fisheries mechanism this paper suggested the future direction of the country in overseas fisheries. We concluded as follows. We shall apply bilateral treaties first, regional fisheries organizations' treaties secondly, and provisions under "UNCLOS" for dispute settlement last.

Clustering Asian and North African Countries According to Trend of Colon and Rectum Cancer Mortality Rates: an Application of Growth Mixture Models

  • Zayeri, Farid;Sheidaei, Ali;Mansouri, Anita
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.4115-4121
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    • 2015
  • Background: Colorectal cancer is the second most common cause of cancer death with half a million deaths per year. Incidence and mortality rates have demonstrated notable changes in Asian and African countries during the last few decades. In this study, we first aimed to determine the trend of colorectal cancer mortality rate in each Institute for Health Metrics and Evaluation (IHME) region, and then re-classify them to find more homogenous classes. Materials and Methods: Our study population consisted of 52 countries of Asia and North Africa in six IHME pre-defined regions for both genders and age-standardized groups from 1990 to 2010.We first applied simple growth models for pre-defined IHME regions to estimate the intercepts and slopes of mortality rate trends. Then, we clustered the 52 described countries using the latent growth mixture modeling approach for classifying them based on their colorectal mortality rates over time. Results: Statistical analysis revealed that males and people in high income Asia pacific and East Asia countries were at greater risk of death from colon and rectum cancer. In addition, South Asia region had the lowest rates of mortality due to this cancer. Simple growth modeling showed that majority of IHME regions had decreasing trend in mortality rate of colorectal cancer. However, re-classification these countries based on their mortality trend using the latent growth mixture model resulted in more homogeneous classes according to colorectal mortality trend. Conclusions: In general, our statistical analyses showed that most Asian and North African countries had upward trend in their colorectal cancer mortality. We therefore urge the health policy makers in these countries to evaluate the causes of growing mortality and study the interventional programs of successful countries in managing the consequences of this cancer.

Current Status of Knowledge, Attitude and Practice (KAP) and Screening for Cervical Cancer in Countries at Different Levels of Development

  • Raychaudhuri, Sreejata;Mandal, Sukanta
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4221-4227
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    • 2012
  • Cancer of the uterine cervix is a worldwide menace taking innumerable womens' lives. The literature is vast and a large number of studies have been conducted in this field. Analyses have shown significant differences exist in terms of screening and HPV testing facilities among high income and low to middle income countries. In addition, acute lack of awareness and knowledge among the concerned population is particularly noted in rural areas of the low income countries. A detailed review of Indian case studies revealed that early age of marriage and childbirth, multiparity, poor personal hygiene and low socio-economic status among others are the principal risk factors for this disease. This review concludes that a two pronged strategy involving strong government and NGO action is necessary to minimize the occurrence of cervical cancer especially in low and medium income countries.