The impact of the 2009-10 El Niño Modoki on U.S. West Coast beaches

Geophysical Research Letters
By: , and 



High-resolution beach morphology data collected along much of the U.S. West Coast are synthesized to evaluate the coastal impacts of the 2009–10 El Niño. Coastal change observations were collected as part of five beach monitoring programs that span between 5 and 13 years in duration. In California, regional wave and water level data show that the environmental forcing during the 2009–10 winter was similar to the last significant El Niño of 1997–98, producing the largest seasonal shoreline retreat and/or most landward shoreline position since monitoring began. In contrast, the 2009–10 El Niño did not produce anomalously high mean winter-wave energy in the Pacific Northwest (Oregon and Washington), although the highest 5% of the winter wave-energy measurements were comparable to 1997–98 and two significant non-El Niño winters. The increase in extreme waves in the 2009–10 winter was coupled with elevated water levels and a more southerly wave approach than the long-term mean, resulting in greater shoreline retreat than during 1997–98, including anomalously high shoreline retreat immediately north of jetties, tidal inlets, and rocky headlands. The morphodynamic response observed throughout the U.S. West Coast during the 2009–10 El Niño is principally linked to the El Niño Modoki phenomena, where the warm sea surface temperature (SST) anomaly is focused in the central equatorial Pacific (as opposed to the eastern Pacific during a classic El Niño), featuring a more temporally persistent SST anomaly that results in longer periods of elevated wave energy but lower coastal water levels.

Study Area

Publication type Article
Publication Subtype Journal Article
Title The impact of the 2009-10 El Niño Modoki on U.S. West Coast beaches
Series title Geophysical Research Letters
DOI 10.1029/2011GL047707
Volume 38
Issue 13
Year Published 2011
Language English
Publisher AGU
Publisher location Washington, D.C.
Contributing office(s) Pacific Coastal and Marine Science Center
Description L13604
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Geophysical Research Letters
Country United States
Google Analytic Metrics Metrics page
Additional publication details