Low latitude volcanic eruptions and the El Niño‐Southern Oscillation

Abstract

AbstractAn apparent association between low latitude volcanic eruptions and the El Niño‐Southern Oscillation (ENSO), has been examined using a superposed epoch composite analysis of Darwin monthly mean pressure, an index of ENSO. Ten eruptions have been included in the analysis. In the composite, the date of eruption tends to be preceded by lower than average pressure at Darwin, and followed by above average pressure. A strong linear upward trend in the composite pressure anomaly starts well before the date of eruptions and continues for several months after the eruption. The analysis suggests that ENSO events are not caused by low latitude volcanic eruptions, since significant anomalies in Darwin pressure, and an upward trend in the anomalies, are observed well before the date of eruption. Low latitude eruptions tend to be preceded by the start of the sequence of events which leads to ENSO.