Coastal sea level measured from tide gauges exhibits coherent variability at interannual and decadal scales. We investigate sea-level variability of large geographic areas using annual mean sea-level values obtained from the longest available records of coastal observations. Eight sea-level regional indices are constructed for the Atlantic and the Pacific Ocean basins. High coherency of sea-level variability at the decadal timescales between different oceanic regions is observed. The role of large-scale atmospheric forcing is then examined by comparison with the El Niño–Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). Strong correlation between the NAO and the second empirical orthogonal function (EOF) of the northwest Atlantic data set was observed. The second EOF is also significantly correlated with the latitudinal position of Gulf Stream and the Arctic Oscillation (AO). Sea-level changes in the northeast Atlantic are driven by the NAO. Correlation with the AO was also observed. In the Pacific Ocean, ENSO dominates sea-level variability along the eastern and southwest sides of the basin. ENSO signatures appear also in the southwest Atlantic, indicating teleconnection patterns. It is proposed that ENSO-related variability in this region is forced through the Pacific–South American teleconnection mechanism. The correlation between southwest Atlantic sea level and ENSO increased after 1980. Sea-level variability on decadal scales in the northwest Pacific region is influenced by the Pacific Decadal Oscillation.
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1 May 2006
Coherent Coastal Sea-Level Variability at Interdecadal and Interannual Scales from Tide Gauges
A. Papadopoulos,
M. N. Tsimplis
Journal of Coastal Research
Vol. 2006 • No. 223
May 2006
Vol. 2006 • No. 223
May 2006
Arctic Oscillation
El Niño–Southern Oscillation
indices
North Atlantic Oscillation
Pacific Decadal Oscillation
regional sea level
Southern Oscillation Index