Volcanic aerosols, El Niñmo and the Southern Oscillation

✍ Scribed by Paul Handler; Karen Andsager

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 900 KB
• Volume: 10
• Category: Article
• ISSN: 0899-8418
• DOI: 10.1002/joc.3370100409

✦ Synopsis

Abstract

In this paper some of the questions raised by Nicholls (1988) concerning the relationship of volcanic aerosols to the El NiñMo/Southern Oscillation are examined and answered. Using Monte Carlo techniques, the statistical significance of the composite sea surface temperature (SST) anomalies and the Southern Oscillation Index (SOI) are reexamined both before and after the eruption of a set of low‐latitude volcanic eruptions. Significantly warmer SST and negative SOI anomalies are found in the composites immediately following the eruption period. These significant anomalies after the composite eruption season are found not to depend on the appearance of cooler SST and positive SOI before the key season, a possibility suggested by Nicholls (1989). This result is in agreement with Parker (1988). The volcanic hypothesis states that low‐latitude volcanic aerosols are the immediate and only cause of warmer than normal SST or El NiñMo. This implies that when no low‐latitude aerosol is present the SST should be cooler than normal. Both of these aspects of the volcanic hypothesis are found to be satisfied to a very high level of statistical significance by the observed SST and SOI data.