Characteristics of Convectively Induced Turbulence Derived from the Weather Radar data in Korea

기상 레이더를 활용한 대류에 의한 난류 강도 및 발생 특성에 대한 연구

Convectively Induced Turbulence (CIT) near deep convection often causes in-flight injuries and fatalities for cruising aircraft. To avoid CIT events, we developed and tested the radar-based CIT detection algorithm using the Spectral Width (SW) information in Korea. For providing an objective intensity of CIT, we converted the radar SW data to an Eddy Dissipation Rate (SW-EDR) using the lognormal mapping technique. When compared with in situ EDR measurements observed from the Aircraft Meteorological Data Relay (AMDAR) data, SW-EDR showed a good agreement in identifying locations and intensities of CIT. To further analyze the characteristics of the CIT, two different types of convective systems are selected: a cloud cluster (CC) case on May 30, 2021 and an isolated thunderstorm (IS) case on July 15, 2021. In these cases, intensities and frequencies in CIT are examined separately by lifecycles: initial, mature, and dissipating stages. As a result, each case shows different trends and peak times of the CIT intensity. In CC case, light and moderate intensity of CIT are prevalent in initial stage, while severe intensity is dominant in mature one. In IS case, the light, moderate, and severe intensities of CIT are frequent not only in initial stage but also in dissipating one. This study suggests that the SW-EDR is more useful for detecting objective intensity and location of CIT than sorely using radar reflectivity. In general, it shows a higher risk of strong CIT in upper part of convective systems, which helps providing a better guidance for avoiding CIT.