Influence of El Nino on the variability of global shoreline position

Rafaël Almar (1) , Julien Boucharel (1) , Marcan Graffin (1) , G. O. Abessolo , Grégoire Thoumyre (1) , Fabrice Papa , R. Ranasinghe , J. Montano , E. W. J. Bergsma , M. W. Baba , F. F. Jin

1 LEGOS - Laboratoire d'études en Géophysique et océanographie spatiales

In this study, the authors use a global dataset of satellite-derived shoreline positions, and demonstrate that their interannual evolution is dominated by El Nino through its worldwide influence of sea level, river discharge and ocean waves Coastal zones are fragile and complex dynamical systems that are increasingly under threat from the combined effects of anthropogenic pressure and climate change. Using global satellite derived shoreline positions from 1993 to 2019 and a variety of reanalysis products, here we show that shorelines are under the influence of three main drivers: sea-level, ocean waves and river discharge. While sea level directly affects coastal mobility, waves affect both erosion/accretion and total water levels, and rivers affect coastal sediment budgets and salinity-induced water levels. By deriving a conceptual global model that accounts for the influence of dominant modes of climate variability on these drivers, we show that interannual shoreline changes are largely driven by different ENSO regimes and their complex inter-basin teleconnections. Our results provide a new framework for understanding and predicting climate-induced coastal hazards.

Mots clés: PACIFIQUE; MONDE

Domaines: Planète et Univers [physics]

Rafaël Almar, Julien Boucharel, Marcan Graffin, G. O. Abessolo, Grégoire Thoumyre, et al.. Influence of El Nino on the variability of global shoreline position. Nature Communications, 2023, 14 (1), 3133 [13 p.]. ⟨10.1038/s41467-023-38742-9⟩. ⟨hal-04430149⟩