• Atmosphere
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• v.27 no.4
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• pp.435-444
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• 2017

By analyzing Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE) from May to September for 1951~2007, this study investigates impacts of two dominant boreal summer intraseasonal oscillation (BSISO) modes on precipitation over Monsoon Asia including Korea and long-term change of 10~20-day and 30~60-day ISO over Korea. It is shown that BSISO strongly modulates rainfall variability over the many part of Monsoon Asia including Korea. Korea tends to have more (less) rainfall during the phases 3~5 (7~8) of BSISO1 representing the canonical northward/northeastward propagating 30~60-day ISO and during the phases 6~8 (3~5) of BSISO2 representing the northward/northwestward propagating 10~20-day ISO. It is found that the 10~20-day ISO variability contributes to summer mean rainfall variability more than 30~60-day ISO over Korea. For the 57 years of 1951~2007, the correlation coefficient between the May to September mean precipitation anomaly and standard deviation of 10~20-day (30~60-day) ISO is 0.71 (0.46). It is further noted that there is a significant increasing trend in the 10~20-day and 30~60-day ISO variability in the rainy season during the period of 1951 to 2007.