The contribution of super typhoons to tropical cyclone activity in response to ENSO

摘要

Western North Pacific tropical cyclone (TC) activity is known to have a significant response to El Ni?o and Southern Oscillation (ENSO). Among the TC intensity classifications, “super typhoon”, is widely used as a symbolic word for warning people about the potential for experiencing the most severe typhoon. This study quantifies the contribution of super typhoons to TC activity in response to ENSO, where the Southern Oscillation Index (SOI) is used to indicate the internal variation of ENSO. It is found that the number and the genesis location of non-super typhoons are little influenced by ENSO, and the changes are mostly by the addition of super typhoons. Historical levels of El Ni?o and La Ni?a span from ?2σ to +2σ of the SOI. Over this range of SOI values, the mean response is 5.6 super typhoons (7.1 for El Ni?o and 1.5 for La Ni?a) which nearly matches the mean response overall of 6 storms (24.6 for El Ni?o and 18.6 for La Ni?a). The spatial distribution of TC genesis locations for different ENSO conditions does not completely explain these results.