Coastal Impacts of an El Niño Season

Abstract

Every winter, storms in the Pacific Ocean create large waves that attack the west coast. During El Niño winters, Pacific Ocean storms are often more intense and frequent, thereby increasing the amount of wave attack along our shores. High waves, elevated sea level, and extreme rainfall are commonly associated with El Niño events. The combination of elevated sea level and storm waves can result in extensive coastal erosion while high rainfall events can result in landslides and coastal flooding. One benefit the coast derives from landslides and flooding is the introduction of sediment to the littoral zone for later beach building episodes.

The El Niño winter of 1982/83 was particularly devastating along the California coast, wreaking havoc on beaches and coastal properties. Available data indicate that the current 1997-98 El Niño event is as strong or stronger than the 1982/83 event, however, it is very difficult to predict exactly where the greatest storm impact will occur. Storm tracks are guided by the position of atmospheric high and low pressure cells which in turn are related to such complex phenomena as the jet stream. Scientists have recognized the strong signals of the present El Niño but at present they cannot accurately predict the area of maximum effect.

This abstract (WPG# M98-0240) is from Monterey Bay National Marine Sanctuary Symposium, Sanctuary Currents '98, Human Influences on the Coastal Ocean, Poster Session, 1998.