Characteristics of hail climate distribution and changing trends over DPR Korea during 1981–2020.

The research analyzed the characteristics of hail climate and its long-term change in the northern part of the Korean peninsula using hail observation data from 148 major ground meteorological stations from 1981 to 2020. The results showed that hails in the northern part of the peninsula are mainly distributed in the northern mountainous area and the western plain area, and the average annual hailing days (AHD) in the abovementioned areas were 2 days and 1 day, respectively. The distribution of AHD takes a noticeable seasonal character: it is mainly concentrated in the northern and central mountainous areas in spring with the number of 0.6 days, in the northern mountainous areas in summer with the number of 0.7 days and in the western coastal area in autumn with the number of 0.6 days. The appearance of hail has clear characteristics of change, and the maximum time of hail appearance at the Pyongyang station was 13:00 LST. During the research period, the AHD notably decreased at all observation stations across the country. The research also analyzed the changing trend of the recent hail climate using Normalized Convective Available Potential Energy (NCAPE), Freezing Level Height (FLH), and Vertical Wind Shear (VWS) values calculated from aerological observation data in Pyongyang station. The results showed that the changing trend of FLH and VWS correspond to the change of hail climate, but the change of NCAPE tends to be inconsistent with the change of hail climate. [ABSTRACT FROM AUTHOR]