Winter precipitation variability over Korean Peninsula associated with ENSO

Abstract

In this study, winter precipitation variability associated with the El Niño-Southern Oscillation (ENSO) over the Korean Peninsula was investigated using a 5-pentad running mean data because significant correlation pattern cannot be revealed using seasonal-mean data. It was found a considerably significant positive correlation between Niño3 sea-surface temperature and precipitation during early winter (from Mid-November to early-December), when the correlation coefficient is close to 0.8 in early-December; the correlation is distinctively weakened during late winter. It is demonstrated that such sudden intraseasonal change in relation to ENSO is associated with the presence of anticyclonic flow over the Kuroshio extension region (Kuroshio anticyclone). In early winter, there is strong southerly wind over the Korean Peninsula, which is induced by the Philippine Sea anticyclone and Kuroshio anticyclone. However, in January, although the Philippine Sea anticyclone develops further, the Kuroshio anticyclone suddenly disappears; as a result, the impact of ENSO is considerably weakened over the Korean Peninsula. These results indicate that the Kuroshio anticyclone during El Niño peak phase plays a critical role by strongly affecting Northeast Asia climate, including the Korean Peninsula. In addition, it is also found that there are distinctive interdecadal changes of the relationship between ENSO and precipitation over the Korean Peninsula. In particular, the strong correlation in early winter is clearer in the recent 30 years than that in the previous period of 1950-1979. © 2013 Springer-Verlag Berlin Heidelberg

Precipitation variability in September over the Korean Peninsula during ENSO developing phase

“…The correlation is calculated based on sliding window with pentad interval. Note the Son et al (2014) showed the similar analysis with respect to NDJ Niño3 SST. Since the persistence of Niño3 SST is strong from September to the following winter, the results are quite similar.…”

“…The background state of the LBM is calculated from the monthly climatology (September) during 1979-2012. Son et al (2014) showed that the present LBM simulate the observational features reasonably well for the December and January cases. In this study, we apply the LBM to the September case.…”

“…The analyzing period is chosen to match the period of the global precipitation and circulation data. As Son et al (2014) shown in their Fig. 3, the relationship for the September precipitation is not much sensitive to the analyzing period.…”

“…It is found that the relationship between regional climate and ENSO is abruptly changed in the seasonal evolution, so that the monthly mean data cannot resolve such abrupt changes. Considering the strong seasonal dependency of the ENSO-precipitation relationship, 5-pentad running mean data is used in this study (Son et al 2014). We also used monthly-mean CPC Merged Analysis of Precipitation (CMAP; Xie and Arkin 1997) data onto a 2.5° × 2.5° grid during 1979-2012 to show precipitation variability over East Asia, including the Korean Peninsula.…”

Changes in weather and climate extremes over Korea and possible causes: A review

“…(Ahn et al, 1997;Kang 1998;Cha et al, 1999;Kug et al, 2010;Son et al, 2014;Yeh et al, 2014). As an example, Cha et al (1999) showed that the variability of rainfall over Korean peninsula during the El Niño/La Niña periods is considerably different from that during the normal years.…”