Global climate teleconnection with rainfall erosivity in South Korea

Rainfall Erosivity Index (REI) defined as the product of rainfall kinetic energy and rainfall intensity is a well-known hydrologic indicator of the potential risk of soil erosion. Global and regional scale climatic teleconnections with REI variability over South Korea are examined. We calculate leading patterns of observed monthly REIs using the Empirical Orthogonal Teleconnection (EOT) and Function (EOF) decomposition techniques. Also we used monthly statistical analyses using cross-correlation and lag regression for the leading modes and global atmospheric circulation measurement in the Pacific and Indian Ocean. As a result, the northern inland mode is applicable during summer season and the southern coastal mode applies to fall-winter season. The temporal evolution of REI exhibits mostly increasing and depends on interdecadal oscillation patterns. The leading EOT modes explain more variance in REI than the EOF modes during warm and cold seasons. The findings from this study illustrate that the tropical ENSO forcing has the coherent association with fall and winter REI patterns, and the Indian Ocean dipole is identified as a driver for REI variability in November. The monsoon circulations over western North Pacific also exhibit significant negative correlation with the December modes. The September leading modes also show a positive correlation with the tropical cyclone activity. Leading patterns in September and November have predictability up to five month lead time from the tropical Pacific Sea Surface Temperatures (SSTs). In addition, predictability from the Pacific SSTs for above normal extreme value of REI is greater than that for below normal value in winter. In conclusion, South Korea experiences climatic teleconnection between the large scale climate indices and mid-latitude hydrologic variables.