웨이블릿 일치성 분석을 통한 ENSO 및 AO의 주기적 영향 비교와 한국 적설량 응답 특성 = Comparative analysis of ENSO and AO periodic influences on Korean snowfall using Wavelet coherence

다국어 초록 (Multilingual Abstract)

This study investigates the spatiotemporal coherence between snowfall in South Korea and two major climate oscillation indices—El Niño–Southern Oscillation (ENSO, Niño 3.4 index) and Arctic Oscillation (AO)—over the period from 2005 to 2024. Using daily snowfall data from nationwide ASOS stations and monthly ENSO/AO indices, wavelet transform coherence (WTC) analysis was employed to capture the frequency- and time-specific relationships between the indices and snowfall. The results indicate that ENSO exerts a persistent and long-term influence on Korean snowfall, with a peak coherence of 0.837 at a 48-month periodicity. ENSO-related episodes such as El Niño and La Niña coincide with elevated coherence and a lagging phase response from snowfall, suggesting its predictive utility. In contrast, AO demonstrated intermittent and short-term coherence patterns, peaking at a 28-month period (coherence = 0.688) but showing greater temporal variability and regional disparity. These findings highlight the contrasting dynamical roles of oceanic and atmospheric oscillations in modulating winter snowfall patterns over Korea and offer insights for improved seasonal forecasting and climate risk management strategies.