장기간 한반도 낙뢰 분포 특성과 지형 및 배경류와의 관련성 연구

Abstract

This study aims to harmonize the long-term data from the Total Lightning Detection System (TLDS; 2002~2015) and the Lightning Detection Network (LINET; 2015~2023), producing the first consistent 22-year lightning climatology over the Korean Peninsula. Spatially, flash density maxima are found over the Yellow Sea (~125.5oE) and the western inland, associated with low-level convergence zones in upslope areas of the Taebaek and Sobaek mountain ranges. Interannually, a statistically significant long-term decreasing trend in lightning activity is newly revealed over the Yellow Sea, South Sea, and adjacent inland regions. Seasonally, lightning follows a unimodal distribution with a distinct August peak (35.8%), which is surprisingly different from the bimodal pattern of seasonal heavy rainfall frequency. On the other hand, the lightning data exhibits a bimodal structure in diurnal distribution. 1) A late afternoon maximum over inland regions (1600~1700 LST), which is likely associated with thermally driven convection and topographic effect. 2) An early morning peak (0500~0600 LST) over the Yellow and South Seas, which is likely influenced by the interaction of nocturnal low-level jets with land breezes. A Hovmöller analysis highlights a prominent dawn peak in July over the eastern Yellow Sea and western inland areas, linked to an elongated low-level jet from inland China and enhanced integrated vapor transport in nighttime. These conditions favor the development of the elevated nocturnal convection propagating to the inland with large amount of lightning. This study eventually provides new insights into the spatiotemporal variability of lightning climatology in Korea.