Impact of self-attraction and loading on the annual cycle in sea level.
Tamisiea, Mark E.
Hill, Emma M.
Ponte, Rui M.
Davis, James L.
Vinogradova, Nadya T.
Date of Issue2010
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 ∼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 ∼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.
Journal of geophysical research
© 2010 by the American Geophysical Union (AGU). This paper was published in Journal of Geophysical Research and is made available as an electronic reprint (preprint) with permission of AGU. The paper can be found at DOI: [http://dx.doi.org/10.1029/2009JC005687]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.