On the Recent Global Mean Sea Level Changes: Trend and Seasonality Extraction
Haddad, Mahdi; Taibi, Habib
Centre of Space Techniques, ALGERIA
The spatial sampling offered by TOPEX and Jason series of satellite radar altimeters and its continuity during the last twenty years are major assets to provide an improved vision of the global mean sea level (GMSL). The objective of this paper is to examine the recent GMSL variations (1993-2011). To this end, a global mean sea level anomalies time series, obtained from TOPEX, Jason-1 and Jason-2 measurements, is used to estimate the trend and seasonal components of GMSL changes, using a simplified form of an unobserved components model. Our GMSL trend gives a rate of 3.15 ± 0.4 mm/year between 1993 and 2011. Although the extracted global trend indicates a rise in the mean level of the oceans, there are marked fluctuations over short periods, which are least partly related to El Niño/La Niña episodes.