• Title/Summary/Keyword: North pacific

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Characteristics of Tropical Cyclones over the Western North Pacific in 2008 (2008년 태풍 특징)

  • Cha, Eun-Jeong;Hwang, Ho-Seong;Yang, Kyung-Jo;Won, Seong-Hee;Ko, Seong-Won;Kim, Dong-Ho;Kwon, H. Joe
    • Atmosphere
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    • v.19 no.2
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    • pp.183-198
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    • 2009
  • The purpose of this study is to summarize the tropical cyclone (TC) activity of 2008 over the western North Pacific including the verification of the official track and intensity forecast errors of these TCs. The TC activity - frequency, Normalized Typhoon Activity (NTA), and life span - was lower than 58-year (1951-2008) average. 22 tropical cyclones of tropical storm (TS) intensity or higher formed in the western North Pacific and the South China Sea in 2008. The total number is less than 58-year average frequency of 26.4. Out of 22 tropical cyclones, 11 TCs reached typhoon (TY) intensity, while the rest 11 TCs only reached severe tropical storm (STS) and tropical storm (TS) intensity - six STS and five TS storms. One typhoon KALMAEGI (0807) among them affected the Korea peninsula. However, no significant impact - casualty or property damage - was reported. On average of 22 TCs in 2008, the Korea Meteorological Administration (KMA) official track forecast error for 48 hours was 229 km. There was a big challenge for individual cyclones such as 0806 FENGSHEN and 0817 HIGOS presenting significant forecast error, with both intricate tracks and irregular moving speed. The tropical cyclone season in 2008 began in April with the formation of NEOGURI (0801). In May, four TCs formed in the western North Pacific in response to enhanced convective activity. On the other hand, the TC activity was very weak from June to August. It is found that the unusual anti-cyclonic circulation in the lower level and weak convection near the Philippines are dominant during summertime. The convection and atmospheric circulation in the western North Pacific contributed unfavorable condition for TC activity in the 2008 summertime. The 2008 TC activity has continued the below normal state since mid 1990s which is apparent the decadal variability in TC activity.

An Analysis of Operational Efficiency and Productivity for deep-sea fishing vessels in the North Pacific Ocean (북태평양 조업선박의 운영 효율성 및 생산성 분석)

  • Cho, Wooyoun;Jo, Geonsik;Yeo, Gitae
    • Journal of Korea Port Economic Association
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    • v.30 no.2
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    • pp.113-132
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    • 2014
  • With the global warming phenomenon, the deep sea water area that fishing vessels can enter and operate is ever widening. For example, the Arctic Ocean recently has overall competitive advantages due to having many deep-sea fish stocks. The North Pacific region is a strategic coastal district, the closest access point of Arctic Ocean. For Korean fishing vessels which now operate in North Pacific region, and want to entry the Arctic Ocean, the analysis of technical efficiency is needed for preparing the better industry's future. This paper aims to analyze the relative efficiency, and select the low effective deep-sea fishing vessels in the North Pacific, and to suggest their desirables strategies. As a research methodology, Data Envelopment Analysis (DEA) and Malmquist Index are applied to 16 fishing vessels for the periods(2009 to 2013). To draw out the efficiency of targeted deep-sea fishing vessels, gross tons, horsepowers, and operating days are used as input variables while total catch stands for an output variable. As a result, CCR efficiency, BCC efficiency and scalability efficiency are measured to be 0.8405, 0.9484 and 0.8858 respectively for 5 years (2009 to 2013). In conclusion, 38% of total tons, 36% of horsepowers and 29% of operating days each fishing vessel should be reduced to keep their competitive powers.

Breast Screening in North India: A Cost-Effective Cancer Prevention Strategy

  • Pandey, Saumya;Chandravati, Chandravati
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.853-857
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    • 2013
  • Objectives: Breast cancer is a leading cause of morbidity and mortality in women worldwide. Breast screening in normal and/or asymptomatic women is essential to reduce the burden of breast malignancies. Our study aimed to identify possible risk- and/or co-factors associated with breast screening in North Indian women. Methods: A public health research survey was conducted among 100 women of North Indian ethnicity during clinic visits in a 6-month timeline (April-October 2012). Demographic and clinical data, including mammography screening, were recorded in the questionnaire-based proforma after conducting a 10 minute interview. Written informed consent was taken from all the participants. Results: The mean age of the participants was $32.2{\pm}9.9$ years. Out of 100 women, 6% had family history of breast disease. Breast-related complaints/malignancy, including galactorrhoea, mastitis, axillary lump, fibrocystic disease, fibroadenosis and adenocarcinoma were observed in 41% participants; age stratification revealed that 82.9% of this group (n=41) were <30 years, while 9.7% and 7.3% were >30 years and 30 years of age, respectively. 32% participants underwent mammography screening and 8% had breast ultrasound imaging. Age stratification in the mammography screening group demonstrated that 24 women were <40 years, while 7 women were >40 years. Conclusions: Our pilot study identified possible co-factors affecting breast screening in North Indian women. These findings may be beneficial in early detection of breast abnormalities, including malignancies in women susceptible to breast cancer, and thus aid in future design of cost-effective screening strategies to reduce the increasing burden of breast carcinoma in women worldwide.

Additional Records of the Hydrothermal Vent Scale Worm Branchinotogluma segonzaci (Polynoidae: Lepidonotopodinae) from the North Fiji Basin and Tonga Arc

  • Lee, Won-Kyung;Lee, Geon Hyeok;Ju, Se-Jong;Kim, Se-Joo
    • Animal Systematics, Evolution and Diversity
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    • v.37 no.4
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    • pp.273-279
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    • 2021
  • Branchinotogluma segonzaci (Miura and Desbruyères, 1995) occurs in hydrothermal vent fields of the southwestern Pacific Ocean. We morphologically compared B. segonzaci from the North Fiji Basin with the original description from the Lau Basin and a subsequent study of specimens from the Manus Basin. The main characteristics of all B. segonzaci populations were similar having 21 segments, 10 pairs of elytra, cylindrical-shaped anterior lobes, and ventral papillae on segment 12 and ventral lamellae on segments 13-17 in males. However, the specimens from the North Fiji Basin had rounded to sub-renifrom elytra rather than oval in the original description. Additionally, we newly obtained 11 cytochrome oxidase subunit I (COI) DNA barcodes from the North Fiji Basin and Tonga Arc populations and compared them with known COI DNA barcodes of Branchinotogluma species. Thirteen sequences of B. segonzaci showed 0.0-1.07% intraspecific variation and formed two clades in the COI neighbor-joining tree, whereas the interspecific variation among Branchinotogluma species was 8.19-22.4%. The results of this study contribute to biogeographic studies of B. segonzaci and the evolution of polynoid scale worms in chemosynthesis-based ecosystems.

Nasopharyngeal Carcinoma Incidence in North Tunisia: Negative Trends in Adults but not Adolescents, 1994-2006

  • Wided, Ben Ayoub Hizem;Hamouda, Boussen;Hamadi, Hsairi;Mansour, Ben Abdallah
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2653-2657
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    • 2015
  • Nasopharyngeal carcinoma (NPC) is the second most common neoplasm of head and neck in Tunisia. The distribution is bimodal with a first period occurrence between 15 and 20 years old and a second peak at around 50 years of age. Undifferentiated carcinoma of nasopharynx type III (UCNT) is the predominant histological type (93.4%). Data of cancer registry of North Tunisia confirmed that it is an intermediate risk area for NPC with overall ASRs of 3.6 and 1.6/100,000 respectively in males and females. This study aimed to present the evolution of incidence rate of nasopharyngeal carcinoma over a period of 12 years (1994-2006). Data of cancer registry of North Tunisia (NTCR), covering half of the Tunisian population, were used to determine evolution of NPC incidence, calculated by 5 year periods. The estimated annual percentage change (EAPC) was used as an estimate of the trend. To best summarize the behavior or the data trend across years, we used a join-point regression program. Between 1994 and 2006, we observed negative annual average change of standardized incidence in men and women (-3.3%and -2.7%) also for the standardized incidences which showed a rather important decline (26.4% in males and 22.3% in females). The truncated age standardized incidence rate of NPC in adults aged of 30 years old and more (N= 1209) decreased by -0.4% per year from 1994 to 2006 over time in north Tunisia dropping from 6.09 to 4.14 person-years. However, the rate was relatively stable during this period among youths aged 0-29 years (N= 233) in both sexes. NPC demonstrated a favorable evolution from 1994-2006 probably due to a improvement in socioeconomic conditions.

Distribution and Migration of Flying Squid, Ommastrephes bartrami (LeSueur), in the North Pacific (북태평양에 있어서 빨강오징어 Ommastrephes bartrami (LeSueur)의 분포 및 회유)

  • GONG Yeong;KIM Yeong Seung;KIM Soon Song
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.166-179
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    • 1985
  • The seasonal distribution and migration of flying squid, Ommastrephes bartrami (LeSueur), in the North Pacific were studied by means of mantle length, surface temperature, and catch and effort data of the Korean drift gillnet fishery from 1980 to 1983. The water temperature for the best fishing ranged from $15^{\circ}\;to\;16^{\circ}C$ in May through July and from $13^{\circ}\;to\;18^{\circ}C$ in August through January. High densities of flying squid were found in the thermal fronts with $18^{\circ}C$ isotherm in August and with $15^{\circ}C$ isotherm in September. The densities of flying squid were higher in the western region than in the eastern region in the North Pacific. The high densities of flying squid in the northwestern Pacific were attributed to the high gradients of oceanographic properties in the region. Migration models for flying squid were hypothesized based on the monthly distributions of catch per unit net, mantle length compositions by statistical blocks, and the hydrographic features of the North Pacific. The large flying squid moved to the northern region and to the central Pacific region earlier than the small sized group in the northward migration period (from June to August). Flying squid begin the reverse southward migration from the Subarctic Frontal Zone in autumn with onset of cooling and the development of Oyashio Current. The large sized group starts their southward return migration from more northern waters than the small sized group but the former moves past the later ana reaches the spawing ground first.

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Climate Variability and Chum Salmon Production in the North Pacific (북태평양 기후변화와 연어 생산력 변동)

  • Kim, Su-Am;Kang, Su-Kyung;Seo, Hyun-Ju;Kim, Eun-Jung;Kang, Min-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.2
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    • pp.61-72
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    • 2007
  • The relationship between North Pacific chum salmon (Oncorhynchus keta) population and climate variability was investigated in the North Pacific ecosystem. Time-series for the Aleutian Low Pressure, Southern Oscillation, Arctic Oscillation, and Pacific Decadal Oscillation (PDO) indices dating back to 1950 are compared with the chum salmon catch using a cross-correlation function (CCF) and cumulative sum (CuSum) of anomalies. The results of CCF and CuSum analyses indicated that there was a major change in climate during the mid 1970s, and that the chum salmon population responded to this climate event with a time-lag. The PDO and chum salmon returns showed a highly significant correlation with a time-lag of 3 years, while the AOI with a time-lag of $6{\sim}7$ years. The favorable environments for fry chum salmon might cause better growth in the coastal areas, but higher growth rate during the early stage does not seem to be related to the improved return rate of spawning adults. Rather, growth in the Okhotsk Sea or the Bering Sea during immature stages has a significant correlation with return rate, which implies the size-related mortality process. The development of a local climate index is necessary to elucidate the effect of climate variability on the marine ecosystem around the Korean Peninsula.

Consideration on new research direction in marine environmental sciences in relation to climate change (기후변화에 대비한 환경연구의 방향)

  • Kim, Su-Am
    • Journal of Environmental Policy
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    • v.1 no.1
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    • pp.1-24
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    • 2002
  • Due to the recent increase in greenhouse gases in atmosphere, world climate is rapidly changing and in turn, the earth ecosystem responds upon the climate changes. Comparing the ecosystem in the past, the present shapes of ecosystem is the result of the serious modification. Fishery resources in marine ecosystem, which usually occupy the upper trophic level, are also inevitable from such changes, because they always react to the natural environmental conditions. The northwestern Pacific is the most productive ocean in the world producing about 30% of world catch. From time to time, however, it has been notified that abundance, distribution and species composition of major fish species were altered by climate events. Furthermore, primary productivity of the ocean is not stable under the changing environments, so that carrying capacity of the ocean varies from one climate regime to another. Major climate events such as global warming, atmospheric circulation pattern, climate regime shift in the North Pacific, and El Nino event in the Pacific tropical waters were introduced in relation to fisheries aspects. The current status and future projection of fishery production was investigated, especially in the North Pacific including Korean waters. This new paradigm, ecosystem response to environmental variability, has become the main theme in marine ecology and fishery science, and the GLOBEC-type researches might provide a solution far cause-effect mechanism as well as prediction capability. Ecosystem management principles for multi-species should be adopted for better understanding and management of ecosystem.

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DNA Barcoding of Isaacsicalanus paucisetus (Copepoda: Calanoida: Spinocalanidae) from the Hydrothermal Vent in the North Fiji Basin, Southwestern Pacific Ocean

  • Park, Chailinn;Lee, Won-Kyung;Kim, Se-Joo;Ju, Se-Jong
    • Animal Systematics, Evolution and Diversity
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    • v.36 no.2
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    • pp.182-184
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    • 2020
  • Isaacsicalanus paucisetus Fleminger, 1983, a monotypic species of the family Spinocalanidae Vervoort, 1951, was first reported from a hydrothermal vent field in the East Pacific Rise off the mouth of the Gulf of California. The mitochondrial cytochrome oxidase I(mtCOI) DNA barcodes are considered a useful tool to assist traditional taxonomy and species discrimination in calanoid copepods. However, the mtCOI DNA barcodes of I. paucisetus have not been reported due to the species rarity and the difficulty of sampling. In this study, we firstly determined the mtCOI DNA barcodes of the I. paucisetus newly collected from a hydrothermal vent in the North Fiji Basin of the southwestern Pacific. All mtCOI DNA barcodes of I. paucisetus were identical and intraspecies variations of spinocalanid species were 0.0-3.0%. Interspecies and intergeneric variations were 13.4-25.2% and 16.7-24.1%, respectively. The DNA barcodes of I. paucisetus obtained in the present study would be helpful for understanding taxonomic relationships of widespread spinocalanid species.

A Study on the Track of Typhoon in the Northwest Pacific Ocean (북태평양 서부에서 발생하는 강풍의 진로에 관한 연구)

  • 윤종화
    • Journal of the Korean Institute of Navigation
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    • v.18 no.3
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    • pp.19-30
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    • 1994
  • By use of the recent tropical cyclones' data in the Northwest Pacific Ocean, the occurrence frequency and region of typhoon as well as the features of the monthly mean track were analyzed. As the result of this study, (1) mean occurrence frequency of typhoon per year is 27.5, and 68% of total typhoons were formed in July to October and shown the highest frequency in August. (2) The ave-rage duration of typhoons is 8.5 days, and super typhoon which maximum sustained surface wind speeds is more than 130 knots occurs most frequently in October and November. (3) The highest frequency ap-pears around the Caroline, Mariana and Marshall Islands, and in wintertime, typhoon occurs in lower lati-tude comparing with those in summertime. (4) The typhoon track depends upon the distribution of pres-sure system and steering current in neighbouring areas. The mean track of typhoon can be classified into three types such as westward-moving type, northward-moving type and abnormally moving type. The west-ward-moving typhoons make landfall on the southern China by way of the South China Sea in June and July, on mid-part of China in August and September, and on Indo-china Peninsula in October and Novem-ber. The northward-moving typhoons approximately move on north~northwestward track to $20~30^{\circ}N$ from the occurrence region, then recurve to the East Sea through Korean Peninsula and Kyushu Island in June and July, to the Noth Pacific Ocean along the Japanese Islands in August and September and to the North Pacific Ocean through the seas far south off the Japan in October and November.

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