Recent SST and atmospheric circulation anomaly data suggest that the 2015/16 El Nino event is quickly decaying. Some researchers have predicted a forthcoming La Nina event in late summer or early fall 2016. From the p...Recent SST and atmospheric circulation anomaly data suggest that the 2015/16 El Nino event is quickly decaying. Some researchers have predicted a forthcoming La Nina event in late summer or early fall 2016. From the perspective of the modulation of tropical SST by solar activity, the authors studied the evolution of the 2015/16 El Nino event, which occurred right after the 2014 solar peak year. Based on statistical and composite analysis, a significant positive correlation was found between sunspot number index and El Ni^o Modoki index, with a lag of two years. A clear evolution of El Nino Modoki events was found within 1-3 years following each solar peak year during the past 126 years, suggesting that anomalously strong solar activity during solar peak periods favors the triggering of an El Nino Modoki event. The patterns of seasonal mean SST and wind anomalies since 2014 are more like a mixture of two types of El Nino （i.e. eastern Pacific El Nino and El Nino Modoki）, which is similar to the pattern modulated by solar activity during the years following a solar peak. Therefore, the El Nino Modoki component in the 2015/16 El Nino event may be a consequence of solar activity, which probably will not decay as quickly as the eastern Pacific El Nino component. The positive SST anomaly will probably sustain in the central equatorial Pacific （around the dateline） and the northeastern Pacific along the coast of North America, with a low-intensity level, during the second half of 2016.展开更多
基金supported by the National Basic Research Program of china(973 Program)[grant number 2012c B957804]the External cooperation Program of BIc,chinese Academy of Sciences[grant number 134111KYSB20150016]
文摘Recent SST and atmospheric circulation anomaly data suggest that the 2015/16 El Nino event is quickly decaying. Some researchers have predicted a forthcoming La Nina event in late summer or early fall 2016. From the perspective of the modulation of tropical SST by solar activity, the authors studied the evolution of the 2015/16 El Nino event, which occurred right after the 2014 solar peak year. Based on statistical and composite analysis, a significant positive correlation was found between sunspot number index and El Ni^o Modoki index, with a lag of two years. A clear evolution of El Nino Modoki events was found within 1-3 years following each solar peak year during the past 126 years, suggesting that anomalously strong solar activity during solar peak periods favors the triggering of an El Nino Modoki event. The patterns of seasonal mean SST and wind anomalies since 2014 are more like a mixture of two types of El Nino （i.e. eastern Pacific El Nino and El Nino Modoki）, which is similar to the pattern modulated by solar activity during the years following a solar peak. Therefore, the El Nino Modoki component in the 2015/16 El Nino event may be a consequence of solar activity, which probably will not decay as quickly as the eastern Pacific El Nino component. The positive SST anomaly will probably sustain in the central equatorial Pacific （around the dateline） and the northeastern Pacific along the coast of North America, with a low-intensity level, during the second half of 2016.
