A New Insight on El Niño Diversity: Decadal Variability in Westerly Wind Bursts

ABSTRACT El Niño‐Southern Oscillation (ENSO) is the strongest mode of interannual climate variability, characterized by fluctuations in sea surface temperature (SST) with diverse spatial structures. Recent research has identified two main flavors of El Niño events: Eastern Pacific (EP) and Central Pacific (CP) types, each associated with different physical processes and climatic impacts. However, the causes of El Niño diversity remain widely debated, with westerly wind bursts (WWBs) recognized as a major contributing factor. This study investigates the relationship between WWBs and El Niño diversity, focusing on decadal variations in the cumulative intensity (CWI) and longitudinal center (LonCen) of WWBs. Analyses of CWI and LonCen throughout the year and in spring show that CWI exhibits significant decadal variations corresponding to changes in El Niño diversity, with stronger CWI favoring the occurrence of EP El Niño events. While LonCen exhibits a trend of shifting gradually toward the Western Pacific, which aligns with an increased frequency of CP El Niño events. These results further highlight the importance of WWBs, emphasizing not only their intensity but also their spatial pattern, in influencing El Niño evolution and diversity.