The Impact of Barometric Variations on the Sea Level in Coastal Areas Using GNSS Reflectometry

The Local Inverse Barometer (LIB) effect is a complex phenomenon which consists in the response in sea level surface variations to barometric changes. This contribution aims to study the evolution of the impact of this phenomenon on sea level in different sites in coastal areas. Four GNSS stations were used all over the world (Port-Tudy on Groix island (France), Tarifa in Spain, Fort -de- France on Martinique island (overseas France) and Lyttelton in New-Zealand) in order to retrieve coastal sea level height through SNR - based GNSS reflectometry. This sea level height estimates are then extensively compared to oceanic tides and surge effects due to pressure variations. The results show that the impact of the LIB effect on sea level is strongly dependent on the location but also on the spatial extension and timescales.