Surname: Fenoglio-Marc
Firstname: Luciana
Title: Dr.
Organisation: Technical University Darmstadt
Department: Inst. of Physical Geodesy 
Address_1: Petersenstr. 13
Address_2:  
City: 64287
Country: Germany
Email: fenoglio@ipg.tu-darmstadt.de
Phone: +49-6151-163012
Fax: +49-6151-164512

Global and regional sea level variability models in 1900-2005

Dr. Luciana Fenoglio-Marc⁽¹⁾and Dr. Matthias Becker⁽¹⁾

⁽¹⁾ Technical University Darmstadt, Petersenstr. 13, 64287, Germany

Abstract

The study analyses the sea level variability from tide gauge and multi-mission satellite altimetry observations in 1993-2005 and its reconstruction in 1900-2005 using the dominant patterns identified in 1993-2005 together with tide gauge time-series and climatic indices available over the last century.

The method involves performing a decomposition of the single field and of the coupled variability by Principal Component Analysis and by Canonical Correlation Analysis and constructing the sea level using spatial patterns from altimetry and temporal patterns from tide gauge stations. The first dominant modes are chosen to be correlated with the climatic indices, the others are determined to best fit the observations.

We expect the corresponding spatial patterns to be persistent and constant in time, as linked to a physical phenomena. The stability and persistency of the spatial temporal patterns are investigated using sea surface temperature and thermo-steric sea level heights that, differently from the sea level data, are available globally over several decades. In this case the correlation of the dominant modes with the climatic indices is lower than when sea level heights are used.

Globally, in 1993-2005 the empirical model reproduce the interannual variability observed by altimetry in 1993-2005 with a root mean square error of about 2 centimeters and corresponds to about 50% of the interannual variability.

For the construction of the regional empirical model in the European seas multi-mission altimeter data. The comparison between steric interannual variability and observations shows in the Mediterranean Sea a better agreement with altimetry than with some of the tide gauges in the last 15-years. The selection of the tide-gauges is of relevance for the model construction back in time.