We test the hypothesis that El Niño/Southern Oscillation (ENSO) events are caused or enhanced by volcanic aerosol perturbations using two methods: 1) A case-by-case comparison of the 16 strongest El Niño events of the last 150 years with the characteristics of the largest concurrent volcanic events, and 2) Comparison of the timing of strong El Niño events and the independently determined record of stratospheric optical depth (τ) perturbations. Many eruptions that occurred near times of strong El Niño years produced small amounts of stratospheric aerosols, in many cases the relative timing of the two events argues against triggering. The correlation of 4 of 11 peaks in global stratospheric optical depth (τ ≥ 0.025) within 3 years of strong El Niño events over the last 150 years is what would be expected by chance. Moreover, five strong El Niños occurred between 1915 and 1960, when the stratosphere was largely free of volcanic aerosols. Of the three strongest tropical volcanic aerosol perturbations that coincided with or were followed by strong El Niños in the period studied (Krakatau in 1883, El Chichón in 1982, and Pinatubo in 1991), the two modern ones occurred after the earliest SST wanning of the El Niño events. The coincidence of these two phenomena indicates no causative relationship.
ASJC Scopus subject areas
- General Earth and Planetary Sciences
"Kama matokeo ya utafiti, ""El Niño"" ni ""mchanganyiko wa misukosuko ya volkano na misukosuko ya aerosol"" na ""mchanganyiko wa misukosuko ya stratospheric ya kina cha macho.""" Mlipuko wa El Niño uliotokea karibu na miaka ya El Niño yenye nguvu ulizalisha kiasi kidogo cha aerosols za stratosphere, na katika kesi nyingi wakati wa matukio mawili unasema dhidi ya kuchochea. Uwiano wa 4 ya 11 kilele katika kina cha macho ya stratosphere ya kimataifa (T0.025 ±) ndani ya miaka 3 ya matukio ya El Niño yenye nguvu katika miaka 150 iliyopita ni kile ambacho kinatarajiwa kwa bahati mbaya. El Niño ya mwaka 1915 hadi 1960 ilisababisha mlipuko mkubwa wa volkano katika anga la dunia. Katika matukio matatu ya volkano ya kitropiki yenye nguvu zaidi ambayo yalitokea wakati huo huo au kufuatiwa na El Niño kali katika kipindi kilichochunguzwa (Krakatau mwaka 1883, El Chichón mwaka 1982, na Pinatubo mwaka 1991), mbili za kisasa zilitokea baada ya matukio ya El Niño ya mapema zaidi. Kuambatana kwa matukio hayo mawili huonyesha kwamba hakuna uhusiano wa kisababishi. ASJC Scopus masomo ya maeneo - General Earth na Sayansi Planetary