Abstract:
Decadal predictions bridge the gap between the short-term weather/seasonal forecasts and the long-term
climate projections. They target the reproduction of large-scale weather patterns at multi-year time scales
by both recognizing the long memory of some components of the climate system, and explicitly including
the evolution of green-house gas concentrations as an external forcing. This study illustrates the use of
decadal predictions to determine the near-future storminess at regional scales. Specifically, the evolution
of extreme storm surges and sea levels along the Atlantic Iberian coast is assessed. Present (1980-2016)
and near-future (2021-2024) storm surges are simulated over the north-east Atlantic, forced by
atmospheric reanalyses (ERA-Interim) and decadal predictions (MiKlip), respectively. Results are then
statistically analyzed to investigate the short-term effects of climate change and climate variability on
extreme surges and extreme sea levels. Surges will increase mostly in early winter, while tides are largest
in late winter. As a result, the impact of the increase in storminess on the extreme sea levels and coastal
flooding will be modest, and the growth in extreme sea levels will be dominated by the contribution of
mean sea level rise.
