The Spectrum of Sea Level from 4 to 40 Years

Abstract

Maximum entropy spectrum analysis of 33 tide‐gauge records spanning the late 19th and 20th centuries yields persuasive evidence for the 18·6‐yr lunar‐nodal term and a heretofore undetected solar‐cycle signal in sea level. The mean period standard deviation (sd) of the observations are TL= 18·5±1·1 and Ts= 10·9±0·6 yr, respectively, and each has an average amplitude of roughly 9 mm. Additionally, an apparent signal of unknown origin with Tu= 6·3 yr and Au= 14 mm is evidenced. Copyright © 1976, Wiley Blackwell. All rights reserved