Feb 26, 2018

Under-estimated wave contribution to coastal sea-level rise

Angélique Melet, Benoit Meyssignac, Rafael Almar, Gonéri Le Cozannet
Nature Climate Change
  • States that coastal communities are threatened by sea-level changes operating at various spatial scales; global to regional variations are associated with glacier and ice sheet loss and ocean thermal expansion, while smaller coastal-scale variations are also related to atmospheric surges, tides and waves
  • Uses 23 years (1993–2015) of global coastal sea-level observations, we examine the contribution of these latter processes to long-term sea-level rise, which, to date, have been relatively less explored
  • Finds that wave contributions can strongly dampen or enhance the effects of thermal expansion and land ice loss on coastal water-level changes at interannual-to-multidecadal timescales
  • Finds that, along the US West Coast, for example, negative wave-induced trends dominate, leading to negative net water-level trends
  • Concludes that accurate estimates of past, present and future coastal sea-level rise therefore need to consider low-frequency contributions of wave set-up and swash