• Title/Summary/Keyword: Typhoons

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Relations between Variation of Sea Surface Temperatures in the South Sea of Korea and Intensity of Typhoons (남해 해수면온도 변화와 태풍 세기와의 관계)

  • Seol, Dong-Il
    • Journal of Navigation and Port Research
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    • v.32 no.5
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    • pp.403-407
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    • 2008
  • Relations between variation of SSTs(sea surface temperatures) in the South Sea of Korea and intensity of typhoons which passed through the South Sea of Korea was analyzed for 36 years from 1970 to 2005. The SSTs in the South Sea show the rising trends continuously. The mean SST of the last 10 years(1996-2005) is higher $1.03^{\circ}C$ than the mean SST during 10 years(1970-1979). The rising trends are especially strong after 1994. The intensity of typhoon can be shown by the minimum sea level pressure. The minimum sea level pressures of typhoons which passed through the South Sea show the descending trends. The mean minimum sea level pressure of the last 10 years(1996-2005) is lower 10.1hPa than that during 10 years(1970-1979). The correlation analysis shows that the rising of SSTs in the South Sea has relations with the strengthening of intensity of typhoons.

Distribution of Marine Debris collected from the Sandbar Coastline of Nakdong River Estuary after the Typhoons' Passage (태풍 내습후 낙동강 하구 사주해안의 쓰레기 분포)

  • Park, Son;Yoon, Han-Sam
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.13 no.4
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    • pp.1-7
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    • 2007
  • Using field observations, this study estimated the total weight and types of marine debris along the coast of Jinu Island in the Nakdong River Estuary after typhoons Usagi and Nari had passed. A numerical wave model was used to calculate the spatial wave height distribution at the time of the typhoons' passage. This study found that the total accumulation rate of marine debris deposited on the coast after the two typhoons had passed was about $5,769.86\;kg/km^2/day$ at this site, which was 14.42 times as high as that in normal weather. The wave height distribution in the sea off Jinu Island, based on numerical modeling, was $4.1{\sim}3.5\;m$, which was 1.0-2.5 times greater than for the case of other islands. Therefore, it is likely that the concentration of wave energy led to the deposition of marine debris.

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Distribution of Marine Debris collected from the Sandbar Coastline after the Passage of Typhoons, Nakdong River Estuary (태풍 내습후 낙동강 하구 사주해안의 쓰레기 분포)

  • Park, Son;Yoon, Han-Sam
    • Proceedings of KOSOMES biannual meeting
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    • 2007.11a
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    • pp.15-21
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    • 2007
  • Using field observations, this study estimated the total weight and types of marine debris along the coast of Jinu Island in the Nakdong River Estuary after typhoons Usagi and Nari had passed. A numerical wave m며el was used to calculate the spatial wave height distribution at the time of the typhoons' passage. This study found that the total accumulation of marine debris deposited on the coast after the two typhoons had passed was about $5,769.86kg/day/km^2$ at this sitε which was 14.42 times more than during normal weather. The wave height distribution in the sea off Jinu Island, based on numerical modeling, was $4.1^{\sim}3.5$ m, which was 1.0-2.5 times greater than for the case of other islands. Therefore, it is likely that the concentration of wave energy led to the deposition of marine debris.

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Estimation of the National Burden of Disease and Vulnerable Population Associated with Natural Disasters in Korea: Heavy Precipitation and Typhoon

  • Han, Hyun-Jin;Kim, Jong-Hun;Chung, Soo-Eun;Park, Jae-Hyun;Cheong, Hae-Kwan
    • Journal of Korean Medical Science
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    • v.33 no.49
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    • pp.314.1-314.15
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    • 2018
  • Background: Despite its growing significance, studies on the burden of disease associated with natural disasters from the perspective of public health were few. This study aimed at estimating the national burden of disease associated with typhoons and torrential rains in Korea. Methods: During the period of 2002-2012, 11 typhoons and five torrential rains were selected. Mortality and morbidities were defined as accentual death, injury and injury-related infection, and mental health. Their incidences were estimated from National Health Insurance Service. Case-crossover design was used to define the disaster-related excess mortality and morbidity. Disability-adjusted life years (DALYs) were directly assessed from excess mortality and morbidity. Results: The burden of disease from typhoons increased with the intensity, with 107.7, 30.6, and 36.6 DALYs per 100,000 per event for strong, moderate, and weak typhoons, respectively. Burden of disease from torrential rains were 56.9, 52.8, and 26.4 DALYs per 100,000 per event for strong, moderate, and weak episodes, respectively. Mental disorders contributed more years lived with disability (YLDs) than did injuries in most cases, but the injury-induced YLDs associated with strong typhoon and torrential rain were higher than those of lower-intensity. The elderly was the most vulnerable to most types of disaster and storm intensities, and males younger than 65 years were more vulnerable to a strong torrential rain event. Conclusion: The intensity of torrential rain or typhoon was the strongest determinant of the burden of disease from natural disasters in Korea. Population vulnerable may vary depending on the nature and strength of the disasters.

A Three-Dimensional Numerical Study of Effects of Typhoons on Oceanographic Conditions in the Korea Strait

  • Hong, Chul-Hoon
    • Journal of the korean society of oceanography
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    • v.34 no.2
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    • pp.73-85
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    • 1999
  • When typhoons passed around the Korea Strait, some observation in this strait carried out by Mizuno et al. (1986) gives us the following oceanographic features; 1) the direction of the observed current was opposite to the northeasterly wind, 2) temperature rapidly increased having a time lag as the depth deepens, after then decreased with oscillation. A primitive equation ocean model that makes use of a sigma-coordinate system and incorporates a typhoon model was used to examine the mechanism to generate these phenomena. The model region covers the East China Sea, the Yellow Sea, and a portion of the East Sea (Japan Sea). The model well reproduces the observed features, especially in temperature field, and clearly manifests how the above observed features happened. From early time when the typhoon was located in low latitude, an alongshore northward current in the west of Kyushu (hereafter the West Kyushu Current) is generated by an alongshore wind in the typhoon. This current flows into the eastern channel, as a coastal jet, regardless to the wind field within the Korea Strait during this period. The above observed phenomena are generated by this current. The model results indicate that when typhoons pass around the Korea Strait, the West Kyushu Current is generated, and oceanographic condition in the strait should be greatly influenced by this current.

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Abnormal Oceanic Conditions Caused by Typhoons Around the Korean Peninsula (태풍에 의해 발생하는 한국근해 해황이상변동)

  • SUH Young-Sang;GU Ji-Young;HWANG Jae-Dong;LEE Na-Kyung;KIM Bok-Kee;JANG Lee-Hyun;KANG Yong-Q;LEE Dong-In
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.4
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    • pp.417-429
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    • 2003
  • Abnormal oceanic conditions associated with the passage of typhoons are examined using hydrographic and satellite data 1990-2002. During the passage period of typhoons in the Korean waters, an abrupt decrease of sea surface temperature (SST) in range of 5 to $8^{\circ}C$ was observed. The areas of SST decrease were an order of 100-200 km, and the low SST lasted about 15-25 days after passage of typhoon. After passage of typhoon, the water temperatures in the surface mixed layer of 30 m show negative anomalies for quite a long period. In addition, stratification parameters were substantially decreased and chlorophyll a density was rapidly increased.

Temporal and Spatial Variation in the Freshwater Region in Noksan Bay with the Passage of Typhoons Using the POM (태풍통과시 3차원 원시모델을 이용한 녹산만 담수역의 시공간 변화특성)

  • Hong, Chul-Hoon;Park, Se-Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.1
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    • pp.59-69
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    • 2013
  • Temporal and spatial variation in the freshwater region, created by river runoff, of a small bay, caused by the passage of typhoons was examined using a three-dimensional primitive equation model (the Princeton Ocean Model, POM). Numerical experiments were implemented focusing on temporal evolution in the freshwater region in association with typhoon tracks. The model domain covered most of the estuary around the Nakdong River, including Noksan Bay, where river water is periodically released from upstream (Noksan dam). The model showed that the extension of the freshwater region outside of the bay depended strongly on the tracks of typhoons, specifically the associated wind directions and inner flow fields that are accompanied by new clockwise eddies. The model also showed that entrainment from typhoon passage frequently creates salt wedges in the estuary, indicating that organisms in the bay are biologically and chemically influenced with variation in the freshwater region.

Temperature Variations in the Mixed Layer with the Passage of Typhoons Using One-Dimensional Numerical Model (1차원 모델상에서 태풍통과시의 혼합층 수온 변화)

  • Hong, Chul-Hoon;Masuda, Akira
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.1
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    • pp.107-112
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    • 2018
  • One-dimensional numerical model is implemented to investigate temperature variations in the mixed layer depth (MLD) with the passage of typhoons. In the model, we assume a non-divergent, infinite ocean and consider wind effects only, excluding isostatic effects (inverse barometric effects) and upwelling with vertical movement of the water column. Numerical experiments investigate the effects of typhoon tracks on temperature variations, including their dependence on vertical resolutions in the MLD and these results are compared with those in a three-dimensional primitive equation model (POM). The model reproduces features of the observed temperature variations in the MLD fairly well, and implies that wind effects, rather than isostatic effects, play a predominant role in temporal and spatial temperature variations in the MLD. After the passage of typhoons, however, the model does not reproduce well the temperature variations observed in the MLD, because a limitation of the model is its inability to reproduce events such as cyclonic eddy formation (Hong et al., 2011; Masuda and Hong, 2011). The model also shows well the so called 'rightward bias' (Price, 1981) of sea surface cooling which is the most predominant in the right hand side of typhoon's track.

Abnormal oceanic conditions around the Korean peninsula caused by typhoons

  • Suh, Young-Sang;Gu, Ji-Young;Hwang, Jae-Dong;Lee, Na-Kyung;Jang, Lee-Hyun;Jeon, Kyoung-Ok
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.640-641
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    • 2003
  • Abnormal oceanic conditions associated with the passage of typhoons are examined using hydrographic and satellite data 1990-2002. During the passage period of typhoons in the Korean waters, an abrupt decrease of sea surface temperature(SST) in range of 5 to 8 $^{\circ}$ was observed. The areas of SST decrease were an order of 100-200km, and the low SST lasted about 15-25 days after passage of typhoon. After passage of typhoon, the water temperatures in the surface mixed layer of 30m show negative anomalies for quite a long period. In addition, stratification parameters were substantially decreased and chlorophyll a density was rapidly increased.

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Estimation of Extreme Wind Speeds in Korean Peninsula using Typhoon Monte Carlo Simulation (태풍 시뮬레이션을 통한 한반도 극한풍속 추정)

  • Lee, Sungsu;Kim, Ga Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.2
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    • pp.141-148
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    • 2016
  • The long-span bridges such as Incheon Bridge and Seohae Grand Bridge are located on the coastal region effected frequently by strong wind of typhoons. In order to ensure the wind-resistant performance of the structure, estimation of the proper design wind speed is very important. In this study, stochastic estimation of design wind speed incurred by typhoons is carried out. For this purpose, we first established probability distribution of climatological parameters such as central pressure depth, distance of closest approach, translation speed and heading to build statistical model of typhoons, which are employed in Monte Carlo simulation for hypothetical typhoons. Once a typhoon is generated with statistically justified parameters, wind speeds are estimated along its path using wind field model. Thousands of typhoons are generated and their peak wind speeds are utilized to establish the extreme wind speeds for different return period. The results are compared with design basic wind speeds in Korean Highway Bridge Design Code, showing that the present results agree well with similar studies while the existing code suggests higher design wind speed.