Analysis of Seasonal and Regional Duct Tendencies Based on Domestic High-Altitude Meteorological Measurement Data

In this study, we analyzed the seasonal and regional duct tendencies using domestic high-altitude atmospheric measurement data. The meteorological data was collected from seven high-altitude meteorological observatories in South Korea (Baengnyeong Island, Heuksan Island, Jeju Island, Osan, Gwangju, Bukgangneung, and Pohang) over the past nine years (2015~2023). The atmospheric refractive index for all dates is converted into the modified atmospheric refractive index (M-unit), and the atmospheric conditions (normal, sub, super, duct) are classified using the M-unit gradient (∇M). Among these, the occurrence of ducts, which can cause critical detection errors in radar systems due to strong refraction, is closely observed by region, time, and date. According to the results, when analyzed by region, the probability of duct occurrence was higher in coastal areas across all seasons, and when analyzed by season, it occurred frequently in fall in both inland and coastal areas. In addition, the probability of duct formation was higher in the afternoon than in the morning. Based on these results, we propose the average ∇M and representative correction angles by region and date to minimize detection errors in radar system operations.