• Journal of Environmental Science International
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• v.16 no.9
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• pp.1051-1061
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• 2007

The impact of midlatitude synoptic system (upper-level trough) on typhoon intensity change was investigated by analyzing the spatial and temporal characteristics of vertical wind shear (VWS), relative eddy momentum flux convergence (REFC), and potential vorticity (PV). These variables were computed over the radial mean $300{\sim}1,000km$ from the typhoon center by using GDAPS (Global Data Assimilation and Prediction System) data provided by the Korea Meteorological Administration (KMA). The selected cases in this study are typhoons Rusa (0215) and Maemi (0314), causing much damage in life and property in Korea. Results show that the threshold value of VWS indicating typhoon intensity change (typhoon to severe tropical storm) is approximately 15 m/s and of REFC ranges 6 to 6.5 $ms^{-1}day^{-1}$ in both cases, respectively. During the period with the intensity of typhoon class, PVs with 3 to 3.5 PVU are present in 360K surface-PV field in the cases. In addition, there is a time-lag of 24 hours between central pressure of typhoon and minimum value of VWS, meaning that the midlatitude upper-level trough interacts with the edge of typhoon with a horizontal distance less than 2,000 km between trough and typhoon. That is, strong midlatitude upper-level divergence above the edge of the typhoon provides a good condition for strengthening the vertical circulation associated with the typhoons. In particular, when the distance between typhoon and midlatitude upper-level trough is less than 1,000 km, the typhoons tend to weaken to STS (Severe Tropical Storm). It might be mentioned that midlatitude synoptic system affects the intensity change of typhoons Rusa (0215) and Maemi (0314) while they moves northward. Thus, these variables are useful for diagnosing the intensity change of typhoon approaching to the Korean peninsula.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.34-35
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• 2010

The meteorological disasters in the southern coast of Korea were analyzed for 20years from 1989 to 2008 using the Korea meteorological administration's data. The results are summarized as follows. Yearly mean number and the total number of meteorological disasters in the southern coast of Korea during 20 years are 7.5 and 149, respectively. The highest number appears in July followed by August and the third is September. The meteorological disasters from July to September occupied about 42%. The seasonal mean number is most in summer(about 39% of all), the next orders are the autumn, winter and spring. The meteorological disasters in summer are mainly caused by typhoon and changma. The meteorological disasters of a great scale occurred by typhoons(for example, 9112 GLADYS, 0215 RUSA and 0314 MAEMI) which strike in the southern coast of Korea.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.17-21
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• 2011

Characteristics of meteorological disasters in the southern coast of Korea were analyzed for 20 years from 1989 to 2008 using the Korea meteorological administration's data. The main results are summarized as follows. Yearly mean number and the total number of meteorological disasters in the southern coast of Korea during 20 years are 7.5 and 149, respectively. The highest number appears in July followed by August and the third is September. The meteorological disasters from July to September occupied about 42%. The seasonal mean number is most in summer(about 39% of all), the next orders are the autumn, winter and spring. The meteorological disasters in summer are mainly caused by typhoon and heavy rain. The meteorological disasters of a great scale occurred by typhoons(for example, 9112 GLADYS, 0215 RUSA and 0314 MAEMI) which strike in the southern coast of Korea.