• Title/Summary/Keyword: western North Pacific

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Development of a Diagnostic Index on the Approach of Typhoon Affecting Korean Peninsula (한반도에 영향을 주는 태풍의 접근 진단 지수 개발)

  • Choi, Ki-Seon;Kim, Tae-Ryong
    • Journal of the Korean earth science society
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    • v.32 no.4
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    • pp.347-359
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    • 2011
  • This study has developed the index for diagnosis on possibility that typhoons (TYs) affect Korea. This index is closely related to the strength of the western North Pacific high (WNPH), which is calculated as a difference in meridional wind between at the highest correlation area (around Korea) and at the lowest correlation area (sea southeast of Japan) through a correlation analysis between TC frequency that affects Korea and 500 hPa meridional wind. In low frequency years that selected from Korea affecting TC index, anomalous northeasterly is strengthened from Korea to the South China Sea because the center of anomalous anticyclonic circulation is located to northwest of Korea. Thus, TCs tend to move westward from the sea east of the Philippines to the mainland China. On the other hand, in high frequency years, anomalous southwesterly serves as steering flow that more TCs move toward Korea because the center of anomalous anticyclonic circulation is located to sea east of Japan. Consequently, this study suggests that if this index is calculated using real time 500 hPa meridional winds that forecasted by dynamic models during the movement of TCs, the possibility that TCs approach Korea can be diagnosed in real time.

Prostate Cancer Epidemiology in a Rural Area of North Western Greece

  • Grivas, N.;Hastazeris, K.;Kafarakis, V.;Tsimaris, I.;Xousianitis, Z.;Makatsori, A.;Raptis, P.;Aspiotis, S.;Ioachim, E.;Ntemou, A.;Kitsiou, E.;Malamou-Mitsi, V.;Sofikitis, N.;Kordela, V.;Papandreou, C.;Agnantis, N.J.;Stavropoulos, N.E.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.3
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    • pp.999-1002
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    • 2012
  • Epirus is a rural area of North-Western Greece. We reviewed data from 4 hospitals for 4.975 patients who underwent prostate biopsy in Epirus in the twelve year period from 1999 to 2010. Two six -year periods were compared (1999-2004 and 2004-2010). All cases of prostate cancer confirmed by biopsy were recorded and age-standardized incidence rates per 100,000 males were calculated. We also recorded the clinical stage for patients diagnosed in our hospital and correlated this with PSA and Gleason scores. Percentage of positive prostate biopsies was also calculated. There were a total of 1714 new cases during 1999-2010 and the mean annual age-adjusted incidence was 34/100.000. The mean incidences during 1999-2004 and 2005-2010 were 26/100,000 and 42/100,000, respectively. The mean age at diagnosis was 74. The most common Gleason score was 6 and the prevalent clinical stage was T2. Median PSA at diagnosis was 10.8 ng/ml. There was a significant difference between stage cT4 and all other stages regarding PSA value (p=0.000). A positive correlation was found between Gleason score and PSA (p=0.013). These results are in accordance with the incidence rise recorded in neighboring countries of South-East Europe. However we should keep in mind the risk of overdiagnosis and the detection of low-risk cancers that would not have caused morbidity or death during a man's lifetime anyway.

Seasonal Prediction of Tropical Cyclone Activity in Summer and Autumn over the Western North Pacific and Its Application to Influencing Tropical Cyclones to the Korean Peninsula (북서태평양 태풍의 여름과 가을철 예측시스템 개발과 한반도 영향 태풍 예측에 활용)

  • Choi, Woosuk;Ho, Chang-Hoi;Kang, KiRyong;Yun, Won-Tae
    • Atmosphere
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    • v.24 no.4
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    • pp.565-571
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    • 2014
  • A long-range prediction system of tropical cyclone (TC) activity over the western North Pacific (WNP) has been operated in the National Typhoon Center of the Korea Meteorological Administration since 2012. The model forecasts the spatial distribution of TC tracks averaged over the period June~October. In this study, we separately developed TC prediction models for summer (June~August) and autumn (September~November) period based on the current operating system. To perform the three-month WNP TC activity prediction procedure readily, we modified the shell script calling in environmental variables automatically. The user can apply the model by changing these environmental variables of namelist parameter in consideration of their objective. The validations for the two seasons demonstrate the great performance of predictions showing high pattern correlations between hindcast and observed TC activity. In addition, we developed a post-processing script for deducing TC activity in the Korea emergency zone from final forecasting map and its skill is discussed.

Regional Sea Level Variability in the Pacific during the Altimetry Era Using Ensemble Empirical Mode Decomposition Method (앙상블 경험적 모드 분해법을 사용한 태평양의 지역별 해수면 변화 분석)

  • Cha, Sang-Chul;Moon, Jae-Hong
    • Ocean and Polar Research
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    • v.41 no.3
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    • pp.121-133
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    • 2019
  • Natural variability associated with a variety of large-scale climate modes causes regional differences in sea level rise (SLR), which is particularly remarkable in the Pacific Ocean. Because the superposition of the natural variability and the background anthropogenic trend in sea level can potentially threaten to inundate low-lying and heavily populated coastal regions, it is important to quantify sea level variability associated with internal climate variability and understand their interaction when projecting future SLR impacts. This study seeks to identify the dominant modes of sea level variability in the tropical Pacific and quantify how these modes contribute to regional sea level changes, particularly on the two strong El $Ni{\tilde{n}}o$ events that occurred in the winter of 1997/1998 and 2015/2016. To do so, an adaptive data analysis approach, Ensemble Empirical Mode Decomposition (EEMD), was undertaken with regard to two datasets of altimetry-based and in situ-based steric sea levels. Using this EEMD analysis, we identified distinct internal modes associated with El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) varying from 1.5 to 7 years and low-frequency variability with a period of ~12 years that were clearly distinct from the secular trend. The ENSO-scale frequencies strongly impact on an east-west dipole of sea levels across the tropical Pacific, while the low-frequency (i.e., decadal) mode is predominant in the North Pacific with a horseshoe shape connecting tropical and extratropical sea levels. Of particular interest is that the low-frequency mode resulted in different responses in regional SLR to ENSO events. The low-frequency mode contributed to a sharp increase (decrease) of sea level in the eastern (western) tropical Pacific in the 2015/2016 El $Ni{\tilde{n}}o$ but made a negative contribution to the sea level signals in the 1997/1998 El $Ni{\tilde{n}}o$. This indicates that the SLR signals of the ENSO can be amplified or depressed at times of transition in the low-frequency mode in the tropical Pacific.

Relationship between rainfall in Korea and Antarctic Oscillation in June (6월의 남극진동이 한국의 6월 강우량에 미치는 영향)

  • Choi, Ki Seon;Kim, Baek Jo;Lee, Jong Ho
    • Journal of the Korean earth science society
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    • v.34 no.2
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    • pp.136-147
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    • 2013
  • This study examined the effect of the Antarctic Oscillation (AAO) in June on the June rainfall in Korea by using a correlational statistical analysis. Results showed that there is a highly positive correlation between the two variables. In other words, the June rainfall in Korea is influenced by the Mascarene High and Australian High that are strengthened in the Southern Hemisphere, which is a typical positive AAO pattern. When these two anomalous pressure systems strengthen, the cold cross-equatorial flows in the direction from the region around Australia to the equator are intensified, which in turn, force a western North Pacific subtropical high (WNPSH) to develop northward. This pressure development eventually drives the rain belt to head north. As a result, the Changma begins early in the positive AAO phase and the June rainfall increases in Korea. In addition, a WNPSH that develops more northward increases the landfall (or affecting) frequency of tropical cyclones in Korea, which plays an important role in increasing the June rainfall.

Molecular Identification and Morphological Description of Larvae of the Previously Unrecorded Species Cryptacanthodes bergi (Zoarcoidei: Cryptacanthodidae) collected from Gangwon Province, Korea (강원도에서 채집된 등가시치아목 1미기록종, Cryptacanthodes bergi 자어의 분자동정 및 형태기재)

  • Choi, Si-Won;Lee, Soo-Jeong;Kim, Jin-Koo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.2
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    • pp.188-193
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    • 2021
  • On March 13, 2018 two postflexion larval specimens (18.28 mm and 16.80 mm in standard length) belonging to the family Cryptacanthodidae, suborder Zoarcoidei were collected from Sokcho and Gangneung in Gangwon Province. The family Cryptacanthodidae comprises 4 species worldwide: 3 in the North Pacific Ocean and 1 in the western North Atlantic Ocean. As a result of analyzing 620 bp of the mtDNA COI region, the two postflexion larvae collected in this study were identified as Cryptacanthodes bergi by 99.5% agreement with C. bergi adult registered in NCBI. Postflexion larvae of C. bergi are compressed with large eyes and radial pectoral fins and the anus located in front of the center of the body. Melanophores were intensively distributed along the dorsal midline, except for caudal peduncle, and sporadically distributed on the back of the anus. In addition, there were limited star-like melanophores on the back of the gut. This species showed 0.058 genetic distance when compared mtDNA COI region of C. aleutensis, and it was well distinguished in the distribution pattern of black vesicles of the head, count and measurement traits. Considering the morphological and ecological characteristics of this species, we suggest a new Korean name, " Gwisin-jang-gaeng-i ".

New Record of a Lumpfish, Lethotremus awae (Scorpaeniformes: Cyclopteridae) from Korea as a Filling of Distributional Gap in the Western North Pacific (제주도 북부 연안해역에서 채집된 도치과 (Cyclopteridae) 한국미기록종, Lethotremus awae)

  • Kim, Byung-Jik
    • Korean Journal of Ichthyology
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    • v.27 no.2
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    • pp.153-158
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    • 2015
  • Five specimens of Lethotremus awae (Cyclopteridae) were collected from the northern coastal waters of Jeju Island, Korea, during a survey on larval and juvenile fishes flocking to aquatic lamp in 2004 ~ 2007. They were characterized by having a spherical body with three barbel-like tubes on head and the first dorsal fin overgrown by skin with undiscernible rays as well as VIII-9 dorsal fin rays, 8 ~ 9 anal fin rays and 22 ~ 23 pectoral fin rays. A new Korean name, "Eom-ji-do-chi", was proposed for the species.

Statistical Characteristics of sea surface height and sea surface temperature in the Western North Pacific

  • Hwang, Byong-Jun;Kim, So-Hyun;Chung, Hyo-Sang
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.140-143
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    • 1999
  • SSH(Sea Surface Height) from TOPEX/Poseidon and SST data are analyzed to estimate characteristics of annual and inter-annual variations in the East Asian seas(110E - l80E, 20N - 50N) from November 1992 to May 1998. In EOF analysis of SSH and SST, 57% and 97% of the variance are represented by the first two modes. The first mode of SSH and SST shows strong annual variations expected for steric changes. The second mode of SSH shows a long-term variation, but that of SST shows 3 - 4month offset from annual variation. In the EOF analysis of the SSH and SST, 61% and 54% of the total variance are represented by the first three modes. The first mode represented a long-term variation, and the third mode reflected the bi-ennial variation. The first three mode were not strongly correlated with ENSO. We further apply Canonical Correlation Analysis(CCA) to find the dominant correlation patterns with ENSO.

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Change of TC Activity Around Korea by Arctic Oscillation Phase (북극진동의 위상에 따른 한국 부근에서의 태풍 활동 변화)

  • Choi, Ki-Seon;Kim, Tae-Ryong
    • Atmosphere
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    • v.20 no.4
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    • pp.387-398
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    • 2010
  • This study shows that frequency of tropical cyclone (TC) around Korea in summer (June-September) has positive relation with Arctic Oscillation (AO) in the preceding April. In a positive AO phase, each of anomalous cyclone and anomalous anticyclone is developed in low latitude and middle latitude regions of East Asia from the preceding April to summer. As a result, while anomalous southeasterly around Korea serves as a steering flow that TCs move toward this area is strengthened, northwesterly that reinforced in southeastern area of East Asia plays a role in preventing TCs from moving toward this area. In addition, due to this distribution of pressure systems developed in this AO phase, TCs tend to occur, move and recurve in further northeastern region in the western North Pacific than TCs in a negative AO phase. On the contrary, TCs in a negative AO phase mainly move westward toward southern China or Indochina Peninsula from Philippines. Eventually, intensity of TCs is weaker than those in a positive AO phase due to the terrain effect caused by high passage frequency of TCs in mainland China.

Classification of Precipitation Type Using the Wind Profiler Observations and Analysis of the Associated Synoptic Conditions: Years 2003-2005 (윈드프로파일러 관측 자료를 이용한 장마철 강수 형태 분류와 관련된 종관장의 특성 분석: 2003년-2005년)

  • Won, Hye-Yeong;Jo, Cheon-Ho;Baek, Seon-Gyun
    • Atmosphere
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    • v.16 no.3
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    • pp.235-246
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    • 2006
  • Remote sensing techniques using satellites or the scanning weather radars depend mostly on the presence of clouds or precipitation, and leave the extensive regions of clear air unobserved. But wind profilers provide the most direct measurements of mesoscale vertical air motion in the troposphere, even in the context of heavy precipitation. In this paper, the precipitation events during the Changma period was classified into 4 precipitation types - stratiform, mixed stratiform/ convective, deep convective, and shallow convective. The parameters for the classification of analysis are the vertical structure of reflectivity, Doppler velocity, and spectral width measured with the wind profiler at Haenam for a three-year period (2003-2005). In addition, the synoptic fields and total amount of precipitation were analyzed using the Global Final Analyses (FNL) data and the Global Precipitation Climatology Project (GPCP) data. During the Changma period, the results show that the stratiform type was dominant under the moist-neutral atmosphere in 2003, whereas the deep convective type was under the moist unstable condition in 2004. The stratiform type was no less popular than the deep convective type among four seasons because the moist neutral layer was formed by the convergence between the upper-level jet and the low-level jet, and by the moisture transport along the western rim of the North Pacific subtropical anticyclone.