Sea level extremes in Marseille (NW Mediterranean) during 1885–2008

Sea level extremes and their temporal variability have been explored based on the hourly measurements at Marseille tide gauge for the period 1885–2008. A careful quality check has first been applied to the observations to ensure consistency of the record by eliminating outliers and datum shifts. Yearly percentiles have been used to investigate long-term trends of extremes revealing that secular variations in extremes are linked to mean sea level changes. The associated decadal changes show discrepancies between mean sea level trend and extreme fluctuations, due to the influence of the atmospheric forcing. A local regression model based on the generalized Pareto distribution has been applied to derive trends in return levels. The 50-years return levels reach values between 80 and 120 cm. The most significant changes in return levels are characterized by an increase since the 1970s.