Jong-Seong Kug

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El Niño events, characterized by anomalous warming in the eastern equatorial Pacific Ocean, have global climatic teleconnections and are the most dominant feature of cyclic climate variability on subdecadal timescales. Understanding changes in the frequency or characteristics of El Niño events in a changing climate is therefore of broad scientific and(More)
The El Niño–La Niña asymmetry was estimated in the 10 different models participating in the Coupled Model Intercomparison Project (CMIP). Large differences in the “asymmetricity” (a variance-weighted skewness) of SST anomalies are found between models and observations. Most of the coupled models underestimate the nonlinearity and only a few exhibit the(More)
[1] El Niño/La Niña onset is a challenging problem of ENSO prediction. In this study, we introduce two precursors of El Niño and La Niña onsets. One is the equatorial heat content, and the other is the Western Pacific (WP) wind. When the two precursors are considered together, both the El Niño and La Niña onsets can be highly predictable. In particular, the(More)
Basinwide convective anomalies over the IndianOcean (IO) associated with theMadden–Julian oscillation (MJO) sometimes propagate eastward and reach the west Pacific (WP), but sometimes do not. Long-term observations and reanalysis products are used to investigate the difference between the propagating and nonpropagating MJO events. IO convection onset events(More)
[1] Two distinct roles of the Atlantic sea surface temperatures (SSTs), namely, the North Tropical Atlantic (NTA) SST and the Atlantic Niño, on the El Niño–Southern Oscillation (ENSO) variability are investigated using the observational data from 1980 to 2010 and coupled model experiments. It appears that the NTA SST and the Atlantic Niño can be used as two(More)
Recent studies report that two types of El Niño events have been observed. One is the cold tongue (CT) El Niño, which is characterized by relatively large sea surface temperature (SST) anomalies in the eastern Pacific, and the other is the warm pool (WP) El Niño, in which SST anomalies are confined to the central Pacific. Here, both types of El Niño events(More)
[1] In this study, scale interaction between synoptic eddies and low-frequency flow is investigated. The synoptic eddy feedback is a key process in sustaining the low-frequency flow. We show clear evidence using NCEP reanalysis data that there is a general underlying rule—the ‘‘left-hand rule’’, governing the synoptic eddy feedback onto low-frequency flow.(More)
[1] A strong relationship between ENSO (El Nino/Southern Oscillation) and atmospheric short-term variability in the near-surface zonal wind is reported in the present study. On one hand, anomalies in the variance of the short-term atmospheric variability over the western Pacific tend to lead El Nino development. On the other hand, the activity of the fast(More)
[1] The effect of the Indian Ocean on El Niño/La Niña life cycles has been studied using 200-yrs simulation data of a coupled GCM. The results show that the interactive feedback between the ENSO and the Indian Ocean holds the key to the rapid transition to an opposite phase. This remote impact of the IndianOceanSSTanomaly is linked to the change of zonal(More)
[1] It has been recognized that the intensity of the east Asian (EA) summer monsoon has a negative correlation with that of the western North Pacific (WNP) summer monsoon. Here we show that this relationship is much stronger in the recent decade (1994–2004) than in the epoch before 1994 (1979–1993). The first two leading modes of summer-mean precipitation(More)