Surface Pressure and Wind Stress Effects on Sea Level Change Estimations from TOPEX/Poseidon Satellite Altimetry in the Mediterranean Sea

Abstract

Using the classical inverse barometer (IB) correction and the Modèle d?Onde de Gravité à 2 Dimensions (MOG2D) barotropic model in the Mediterranean Sea during the 1993?2002 period, it is shown that surface pressure and wind stress forcing significantly contribute to sea level elevation variations observed with Ocean Topography Experiment (TOPEX)/Poseidon (T/P) satellite altimetry. The barotropic model allows the authors to estimate the high-frequency atmospheric ocean response that is aliased into the altimetric sea level. Applying the model barotropic correction allows them to reduce the T/P standard deviation by a mean of 21% over the whole basin, whereas the classical IB correction reduces the standard deviation by only 16%. The trend in sea level rise is also strongly affected due to the aliasing effect, especially when short periods are considered. On a 3-yr period, the correction associated with either of these two models can reach 10?12 mm yr?1. Applying the barotropic model correction rather than the IB correction can also affect the linear trend estimations by more than 6?7 mm yr?1. For a 9-yr window, the IB/MOG2D correction can contribute 1.8?2 mm yr?1 in magnitude. The local corrected linear trends confirm the previous analysis pattern but on a local scale, with the linear trend magnitudes reaching values between ?24 and +29 mm yr?1.