Scale-based comparison of Sea Level observations in the North Atlantic from Satellite Altimetry and Tide Gauges
A comparative study is carried out for sea level observations in the North Atlantic from tide gauges and satellite altimetry. Monthly tide gauge records from 12 stations in both sides of the North Atlantic from January 1993 to December 2003 and monthly time series of sea level anomalies derived from TOPEX measurements are considered. The degree of association between tide gauge and altimetry observations is analysed for different scales by computing the correlation between the sea level components resulting from a multiresolution analysis based on the maximal overlap discrete wavelet transform. A similar correlation analysis is carried out to assess the relationship between the sea level observations and climate variables: sea surface temperature, precipitation rate and wind speed. The results show that altimetry and tide gauge observations are strongly correlated, as expected, but also that the relation is scale dependent, with covariability driven by the seasonal signal for most stations. For all variables the obtained correlation patterns exhibit significant spatial variability reflecting the diversity of local conditions affecting coastal sea level.
KeywordsSea level satellite altimetry tide gauges discrete wavelet transform
Unable to display preview. Download preview PDF.
- AVISO (1996). User handbook, AVI-NT-02-101-CN, Ed. 3.0.Google Scholar
- Berwin, R. (2003). Topex/Poseidon Sea Surface Height Anomaly Product. User’s Reference Manual, NASA JPL Physical Oceanography DAAC, Pasadena, CA.Google Scholar
- Chambers, D. P., C. F. Mehlhaff, T. J. Urban, D. Fujii. and R. S. Nerem (2002). Low frequency variations in global mean sea level: 1950–2000. J Geophys Res, 107, doi: 10.1029/2001JCOO1089.Google Scholar
- Fernandes, M. J. and M. A. Antunes (2003). Eight years of satellite radar altimetry in the Northeast Atlantic. In: Proc. 3 Assembleia Luso-Espanhola de Geodesia e Geofisica, Editorial UPV. pp. 226–230.Google Scholar
- Percival, D. and Walden, A. 2000. Wavelet methods for time series analysis, Cambridge University Press.Google Scholar
- White, N. L, J. A. Church and J. M. Gregory (2005). Coastal and global averaged sea level rise for 1950 to 2000. Geophys Res Lett. 32, doi: 10.1029/2004GL021391.Google Scholar
- Woodworth, P. L. and R. Player (2003). The permanent service for mean sea level: an update to the 21st century. J Coastal Res. 19, pp. 287–295.Google Scholar