Long-term sea level change in the Mediterranean Sea from multi-satellite altimetry and tide gauges

The long-term sea level change during 1992–2000 is investigated in the Mediterranean Sea from satellite altimetry data of the Topex–Poseidon, ERS-1 and ERS-2 missions and from tide gauge data. Tide gauge data observations during 1996–2000 agree better with Topex–Poseidon that with ERS-2 data. A relative trend between Topex/Poseidon (T/P) and ERS-2 data is observed and reduced by fitting the ERS-2 data to the T/P data. During the first eight years of the T/P mission the average linear sea level change over the entire Mediterranean Sea is 2.2 mm/year, in the western Mediterranean Sea the change is small (0.4 mm/year), while it is higher in the eastern Mediterranean and in the Ionian Sea, 9.3 mm/year and −11.9 mm/year, respectively. The high correlation of sea level height and sea surface temperature variations indicates the observed sea level change is of thermal origin primarily at seasonal scales. At low frequencies the atmospheric pressure and wind field variations play also a role.