A note on the nodal tide in sea level records

Abstract

This note discusses the likely amplitude and spatial dependence of the nodal (18.61 year) tide in mean sea level (MSL) records. The period of this signal is comparable to the length of many MSL records and so could conceivably affect estimates of secular trends and accelerations. However, it is shown that sufficient knowledge of the nodal tide exists to enable "correction" of the records, should that be required. This approach is likely to yield more reliable estimates of trends from medium-length records than a suggested alternative approach of using nodal terms computed from the individual records. © 2012, the Coastal Education & Research Foundation (CERF).