Abstract
Winter precipitation in the Yeongdong region has been known that it is mainly caused by orographic lifting at the east side of the Tae-Baek mountains and air mass modification over the relatively warm surface of the East Sea. So that this precipitation may be critically dependent on the wind direction and speed of the lower atmosphere in the vicinity of the Yeongdong region. This study investigates the characteristics of the lower atmospheric wind which is related with the Yeongdong's winter precipitation. To do this, observations of surface wind and NCEP/NCAR reanalysis wind data are employed for an examination of local and synoptic wind, respectively. Heavy winter precipitation in the Yeongdong region is associated mostly with easteriles at Daegwallyeong: about 90% of them (more than 3mm/3hr) are related with the easteriles. Based on the wind direction of surface observations and NCEP/NCAR reanalysis data, heavy winter precipitation type in the Yeongdong region could be classified into three types; Mountain type, warm-coastal type, and cold-coastal type. The mountain type can be characterized by strong orographic lifting: at all levels, relatively strong northeasterlies are found. The cold-coastal type can be characterized by the advection of cold air parallel to the Tae-Baek mountain range due to mountain barrier effect: vertical wind field shows veering pattern by the cold air advection. It is suggested that the warm-coastal type may be produced by the convergence due to retardation at the surface level: vertical wind field shows backing pattern by the warm air advection.