Siberia 기단(cP) 확장시 동계 광주·전라남도 지방의 대설에 관한 연구

Abstract

The heavy rainfall is a representative weather disaster in winter season. Although many studies about heavy snowfalls in Honam province are made public, this study analyzes the condition of snowfall associated with the expansion of cP by using following meteorological observing datas during a decade(1991～2000) - surface weather chart, upstair weather chart, Skew T-log p diagrams in Gwangju, satellite images and wind profiler chart in Haenam. The continental high is located 40°N 108°E and it's center pressure is above 1046hPa. It is expended southeast or to the middle China and Han-man national boundary and it's mean pressure gradient is 17 hPa in 30～40°N, 120～130°E. Thermal though is formed near 125°N, thermal ridge is located above the west sea and strong wind above 12 kt blew from the northwest. In 850 hPa, geopotential field in Gwangju, mean height is 1449 gpm, mean temperature -10℃, strong cold core was located in Manjuria and thermal through was formed near the Shanhai. The track of thermal though is located 117～121°E when snow begins 124～126° when new snow lay 5㎝ deep. In 500 hPa, geopotential field in Gwangju, mean height 5400 gpm, mean temperature -27.5℃, cut off low is located near Donbei and the cold core located north Majuria or moved to the northeast Wonsan bay. Strong wind field is located 30～35°, strong wind above 45 kt blew from the west in this wind field. The track of through is located 118°N 122°E when snow begins and 126°～130° E when new snow lay 5㎝ deep. The difference of temperature between Maldo SST and 850 hPa, 700 hPa and 500 hPa was 17.6℃, 25.0℃ and 35.1℃ respectively. The equivalent potential temperature at 850 hPa, 293K is located southern area in Korean peninsula, 1000～700 hPa thikness through is located 102°E and 2760 gpm is the line discriminate snow and rain is located 31～34.5°N when new snow lied 5㎝ deep. The differences between air temperature and dew point temperature is 4.1℃ in 1000hPa, 2.8℃ in 850 hPa, that show 850 hPa is wetter than 1000 hPa. The conditions of convective cloud formation in the west sea are same as following. Cloud base air temperature is below -15℃, cloud top height 2.5 km and cloud base pressure below 662 hPa. The wind shear of development stage, mature stage and decline stage is 30～60°, 0～30° and above 60° respectively. These takes 15 hours from the convective cloud development stage to the growth stage, 10 hours from the growth stage to the mature stage and 12 hours from the mature stage to the decline stage.