영동지방 강설량의 경년변화 특성 및 북태평양 SST와의 관계

Interannual variations of snowfall in Youngdong region and their relations to the SST over North Pacific

The characteristic of snowfall at Youngdong area is a key factor which determine the climatology of Korean peninsula. Although the location and characteristic of both cP and mT air-mass are an important factor which determine the snoefall, the Sea Surface Temperature(SST) of the North Pacific as a source of moisture can be a key factor too. To investigate the variation of snowfall at Youngdong area, therefore, we studied the intercorelation of variation between snowfall at Youngdong and SST at North Pacific. The period of dataset used in this study is for 18 years: from 1981 to 1998. The spatial distribution of SST at East-Sea depends on the movement of warm sea current caused by both Dongahn current and coastal current near Japan. According to this study, there were expanding of Siberia high pressure system toward both Younhaejoo and China, generation of mesoscale cyclone at Korean peninsula, and northerly wind which flow along coast line with partially north-easterly wind when there was a heavy snowfall at Youngdong area. This means that the high value of SST at Youngdong area during heavy snowfall dervie increasing of sensible heat flux over sea surface, increasing of easterly wind, and decreasing of air pressure. These processes were the main factors which played an important role for the increasing of moisture convergence and snowfall at Youngdong area. For the occurrence of heavy snowfall at Youngdong area, the following synoptic conditions are required: 1) The high pressure system of Siberia should be expanded toward Yonhaejoo, 2) development of cyclone over northern part of Korea, 3) there is a cyclone at East-Sea. In thoses synoptic condition, there are north-easterly wind influenced by strong sensible and latent heat fluxes from warm sea surface to the lower atmosphere. There heavy snowfall at Youngdong area can be expected in those situation.