Impact of self-attraction and loading on the annual cycle in sea level

TitleImpact of self-attraction and loading on the annual cycle in sea level
Publication TypeJournal Article
Year of Publication2010
AuthorsTamisiea ME, Hill EM, Ponte RM, Davis JL, Velicogna I, Vinogradova NT
JournalJournal of Geophysical Research-Oceans
Date PublishedJul
ISBN Number0148-0227
Accession NumberWOS:000279825200001

The annual exchange of water between the continents and oceans is observed by GPS, gravimetry, and altimetry. However, the global average amplitude of this annual cycle (observed amplitude of similar to 8 mm) is not representative of the effects that would be observed at individual tide gauges or at ocean bottom pressure recorders because of self-attraction and loading effects (SAL). In this paper, we examine the spatial variation of sea level change caused by the three main components that load the Earth and contribute to the water cycle: hydrology (including snow), the atmosphere, and the dynamic ocean. The SAL effects cause annual amplitudes at tide gauges (modeled here with a global average of similar to 9 mm) to vary from less than 2 mm to more than 18 mm. We find a variance reduction (global average of 3 to 4%) after removing the modeled time series from a global set of tide gauges. We conclude that SAL effects are significant in places (e. g., the south central Pacific and coastal regions in Southeast Asia and west central Africa) and should be considered when interpreting these data sets and using them to constrain ocean circulation models.