Monthly climate variation over Korea in relation to the two types of ENSO evolution

Abstract

This study documents monthly temperature and precipitation anomalies over Korea during the different phases of El Nino-Southern Oscillation (ENSO) for the two types of ENSO evolution. The evolution process of ENSO can be classified into two groups based on whether El Nino turns into La Nina in the subsequent year. The first group involves the transition process from El Nino to La Nina, while the second group shows the prolonged El Nino or neutral conditions after the mature phase of El Nino. Because the mid-latitude atmospheric responses as well as the equatorial heating anomalies for the two groups of ENSO are different each other, the ENSO-related climate variation over Korea are investigated separately for the two ENSO evolution groups. In particular, this study focuses on the entire monthly evolution of the temperature and precipitation over Korea during the different phases of ENSO. The statistically robust signals can be found in several particular months, which provides statistical basis for predicting monthly climate over Korea. In addition to the observational data analyses, we further investigate the forecast skill of the Asia-Pacific Economic Cooperation Climate Center (APCC) Multi-Model Ensemble (MME) in simulating two groups of ENSO evolution and their impacts on Korean climate. The result shows that the MME reasonably predicts the two different evolution of ENSO as in observation but their prediction skills for the ENSO-related Korean climate are diverse, which largely depends on the phase of ENSO.