A Study of the Correlation between ElNiño-Southern Oscillation and Indian Ocean Dipole Mode Indices, and Korean Drought Indices

The correlation between ocean climate and Korean drought indices is key in explaining and predicting droughts in Korea. In this study, ocean climate index data, including El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) index values, were subjected to a Pearson correlation analysis with standardized precipitation index (SPI) data. The results of the analysis show that the SPI and ocean climate change are linked, which provides a possible explanation for the effect of ENSO and IOD on drought in Korea. However, because the magnitude of the observed link was not very large, the correlations ENSO and IOD indices, respectively, and SPI are statistically weak. On analysis of monthly data, significant correlations were mainly observed from January to May, with very weak correlations from June to December. Based on a regional analysis, twelve cities were divided into four groups with similar correlations between the analyzed indices.