• Journal of Environmental Science International
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• v.30 no.7
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• pp.557-571
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• 2021

This study aimed to classify typhoons using a more objective index based on strong winds and precipitation data from 1904 to 2019 obtained from the Automated Surface Observing System. The Typhoon Type Index (TTI) was calculated by classifying wind speed and precipitation of each typhoon, thereby revealing the rate and characteristics of the wind-type and rain-type typhoons. In addition, the top 10 typhoons for property damage were analyzed by dividing them into three types according to the typhoon course. The analysis showed that typhoons of type 1, heading north to the west coast, were most clearly affected by the wind. In addition, the impact of the wind was reduced and the impact of rain increased in the order of typhoon type 2 that landed on the southern coast and type 6 that affected the Korean Peninsula through China.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.122-134
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• 1994

The objective of this study is to provide with the hydrometeological and probabilistic characteristics of the storms and winds of typhoons that have been passed through the Korea peninsula during the last twenty-three years since 1961. The paths and intensities of the typhoons were analyzed. Fifty weather stations were selected and the rainfall and wind data during typhoon periods were collected. Rainfall data were analyzed for the patterns and probabilistic distributions. The results were presented to describe the areal distributions of probabilistic characteristics. Wind data were also analysed for their probabilistic distributions. The results obtained from this study can be summarized as follows: 1. The most frequent typhoon path that have passed through the Korean peninsula was type E, which was followed by types CWE, W, WE, and S. The most frequent typhoon intensity was type B, that was followed by A, super A, and C types, respectively. 2. The third quartile typhoon rainfall patterns appear most frequently followed by the second, first, and quartiles, respectively, in Seoul, Pusan, Taegu, Kwangju and Taejon. The single typhoon rainfalls with long rainfall durations tended to show delayed type rainfall patterns predominantly compared to the single rainfalls with short rainfall durations. 3. The most frequent probabilistic distribution for typhoon rainfall event is Pearson type-III, followed by Two-parameter lognormal distribution, and Type-I extremal distribution. 4. The most frequent probability distribution model of seashore location was Pearson type-III distribution. The most frequent probability distribution model of inland location was two parameter lognormal distribution. 5. The most frequent probabilistic distribution for typhoon wind events was Type-I xtremal distribution, followed by Two-parameter lognormal distribution, and Normal distribution.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1988.10a
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• pp.7-12
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• 1988

This study presents rational methods for probability-based estimates of basic design wind speeds in Korea and develops a risk-bases nation-wide map of design wind speeds. The paper examines the fitting of the Type-I extreme model to maximum yearly non-typhoon wind data from long-term records based on the conventional method and to maximum monthly nod-typhoon wind data from short-term records following Grigorin's approach. The paper also reviews the applicability of the method using short records of about 5 years. The basic design wind speeds for typhoon and non-typhoon wind at a station are made to be obtained from a mixed model which is given as a product of typhoon and non-typhoon extreme wind distributions. A practical method which is based on the fitting of the Type I model to records or typhoon and non-typhoon mixed wind data at a station is also preposed in this study.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.53-67
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• 1997

The objective of this study is to provide with the hydro-meteological and probabilistic characteristics of the storms of typhoons that have been passed through the Korean peninsula during the last twenty-three years since 1961. The paths and intensities of the typhoons were analyzed. Fifty weather stations were selected and the rainfall data during typhoon periods were collected. Rainfall data were analyzed for the patterns and probabilistic distributions. The results were presented to describe the areal distributions of probabilistic characteristics. The results obtained from this study can be summarized as follows: 1. The most frequent typhoon path that has passed through the Korean peninsula was type E, followed by types CWE, W, WE, and S. The most frequent typhoon intensity was type B, followed by A, super A, and e types, respectively. 2. The third quartile typhoon rainfall patterns appear most frequently followed by the second, first, and last quartiles, respectively, in Seoul, Pusan, Taegu, Kwangju and Taejon. The single typhoon rainfalls with long rainfall durations tended to show delayed type rainfall patterns predominantly compared to the single rainfalls with short rainfall durations. 3. The most frequent probabilistic distribution of typhoon rainfall event is Pearson type-III, followed by Two-parameter lognormal distribution, and Type-I extremal distribution. 4. The most frequent probability distribution model of seashore location was Pearson type-III distribution. The most frequent probability distribution model of inland location was two parameter lognormal distribution.

• 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.

• Atmosphere
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• v.26 no.2
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• pp.215-226
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• 2016

Conceptual models to analyze both typhoon and Changma using products extracted by the GEO-KOMPSAT-2A (GK-2A) are suggested in this study. The GK-2A which is scheduled to be launched in 2018 has a high resolution, 16 channels, and 52 products. This means GK-2A is expected to obtain high quality images and products, which can detect severe weather earlier than the Communications, Ocean and Meteorological Satellite (COMS). Since there are not enough conceptual models for typhoon and Changma using satellite images and products, our conceptual model can increase both the applicability of satellite data and the accuracy of analysis. In the conceptual model, typhoons are classified as three types by prevailing factors; 1) heavy-rainfall type, 2) wind type, and 3) complex type. For Changma, two types are divided by the characteristics; band type and heavy-rainfall type. Among the high resolution 52 products, each type of typhoon and Changma are selected. In addition, the numerical products and dynamic factors are considered in order to improve conceptual models.

• Atmosphere
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• v.16 no.1
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• pp.1-17
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• 2006

The purpose of this study is to find out the change of statistical characteristics of typhoons affecting the Korean Peninsula. For this purpose, we analyzed the occurrence frequency of typhoon for 50 years (1954-2003) and change of air temperature and sea surface temperature near the Korean Peninsula in the same period. We classified typhoon tracks affecting the Korean Peninsula, and analyzed their trends and the amount of damage by typhoon. While the annual occurrence frequency of typhoon in the western North Pacific gradually decreased, its frequency affecting the Korean Peninsula increased. In addition, the occurrence location migrated northward. This coincides with the increase in air temperature and sea surface temperature around the Korean Peninsula. Typhoon tracks affecting the Korean Peninsula were classified into 7 types. Among them, the occurrence frequency of type 6 and 7 has increased. Although the occurrence frequency is low in type 2, the amount of damage by typhoon and occurrence frequency are increasing recently.

• Atmosphere
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• v.20 no.3
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• pp.239-246
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• 2010

In this study, the climatological characteristics of the landfall typhoons on North Korea are surveyed to estimate the frequency, the intensity, the track, and their damage. The data for the period of 1951-2008 are used from both RSMC (Regional Specialized Meteorological Center) Tokyo Typhoon Center and NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research), EM-DAT (Emergency Events Database). There are the ten highest frequencies from 1961 to 1965 and is one frequency for the period of both 1966-1979 and 1976-1980 respectively. Even if a clear trend on the frequency of typhoon is not defined, it is noticeable the intensity has been weak since the frequency of TS (Tropical Storm) decreased. In order to figure out both the characteristic of intensity and the relation between the typhoon track and the expansion of North Pacific High (NPH), Typhoon's tracks are classified into three types as follows: (I) landing on the west coast of North Korea through the mainland of China, (II) landing on the west coast of North Korea, (III) landing on a central/eastern part of the Korean peninsula through South Korea. More often than not, the characteristic of Type (I) is the case of a landfall after it becomes extratropical cyclone. Type(II) and Type(III) show a landfall as TS grade, by comparision. On the relation between the typhoon's track and the expansion of NPH analyzed, Type (I) shows the westward expansion while both Type (II) and Type (III) show the northward expansion and development of NPH. This means the intensity of a typhoon landfall on North Korea is variable depending on the development of NPH. Finally, only two cases are found among total five cases in EM-DAT, reportedly that North Korea was damaged. And therefore, the damage by the wind of Prapiroon (the $12^{th}$ typhoon, 2000) and heavy rainfall with Rusa (the $15^{th}$ typhoon, 2002) landing on North Korea was analyzed. Moreover, it is estimated both Prapiroon and Rusa have done badly damaged to North Korea as the economical losses of as much as six billion and five hundred-thousand US dollar, respectively.

• Journal of the Korean earth science society
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• v.29 no.1
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• pp.29-44
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• 2008

This study investigates the influence of the developing and decaying El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) on the relation between typhoon intensity and its formation. From the long-tenn data of 57 years ($1950{\sim}2006$), we first defined the developing El $Ni{\tilde{n}}o$ years and the neutral years. During the developing El Nino years, the typhoon intensity has a strong relationship with formation region of the tropical cyclone, which results in an increase of the accumulated cyclone energy and intensity of energy of typhoon. During the developing El $Ni{\tilde{n}}o$ year based on $Ni{\tilde{n}}o$ 3.4 SST, the locations for the formation of the category 4+5 typhoon move to the eastward region. The genesis potential function and the low-level cyclonic vorticity have an important role on the formation of strong tropical cyclones, which eventually develop as a typhoon class. In this study, the dynamic potential (DP) function (Gray, 1977) and EOF 1 and EOF 2 time series (RMM 1 and RMM 2) of real-time multivariate MJO (Wheeler and Hendon, 2004) are used to measure the genesis potential and the low-level cyclonic vorticity, respectively. To investigate the influence of the developing and decaying ENSO, we defined the Type I case of the decaying El $Ni{\tilde{n}}o$ that turnovers to La Nina, and the Type II case of the recovering years to the neutral condition. During the decaying El $Ni{\tilde{n}}o$ years as Type I, the locations of the strong DP, RMM 1 and RMM 2 move to the westward more prominently to induce retard of the strong typhoon developing.

• Computational Structural Engineering
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• v.2 no.2
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• pp.62-72
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• 1989

This study presents rational methods for probability-based estimates of basic design wind speeds in Korea and proposes a risk-based nation-wide map of design wind speeds. The paper examines the fittings of the extreme Type I mode to largest yearly non-typhoon wind data from long-term records, and to largest monthly non-typhoon wind data from short-term records. For the estimation of the extreme typhoon wins speed distribution, an indirect analytical method based on a Monte-Carlo simulation is applied to typhoon-prone regions. The basic desig wind speeds for typhoon and non-typhoon winds at the sites of concern are made to be obtained from the mixed model given as a product of the two distributions. The results of this study show that the proposed models and methods provide a practicable tool for the development of the risk-based basic design wind speed and the design wind map from short-term station records currently available in Korea.