Influence of El Niño on the variability of global shoreline position

Coastal zones are fragile and complex dynamical systems increasingly threatened by anthropogenic pressure and climate change. Using global satellite-derived shoreline positions from 1993 to 2019 and multiple reanalysis products, the study shows that shoreline variability is influenced by three primary drivers: sea level, ocean waves, and river discharge. Sea level directly alters waterline mobility; waves modulate both erosion/accretion and total water levels; rivers affect sediment budgets and salinity-induced water levels. A conceptual global model linking dominant climate variability modes to these drivers reveals that interannual shoreline changes are largely controlled by different ENSO regimes and their inter-basin teleconnections. The results provide a new framework for understanding and predicting climate-induced coastal hazards.

Rafael Almar, Julien Boucharel, Marcan Graffin, Gregoire Ondoa Abessolo, Gregoire Thoumyre, Fabrice Papa, Roshanka Ranasinghe, Jennifer Montano, Erwin W. J. Bergsma, Mohamed Wassim Baba, Fei-Fei Jin