Role of Atmospheric Indices in Describing Shoreline Variability Along the Atlantic Coast of Europe

Beaches are highly variable environments and respond to changes in wave forcing, themselves modulated by climate variability. Here, we analyze three high-quality beach profile data sets to robustly investigate, for the first time, the link between shoreline change, wave forcing and climate variability along the Atlantic coast of Europe. Winter wave conditions are strongly associated with North Atlantic Oscillation (NAO) and Western Europe Pressure Anomaly (WEPA), with WEPA explaining 50%-80% of the winter wave power variability. Shoreline variability during winter is also strongly linked to NAO and WEPA, with WEPA explaining 25% of the winter shoreline variability. Winter wave conditions and associated shoreline variability are both unrelated to El Nino Southern Oscillation. In addition to the atmospherically-forced beach morphological response, shoreline change also depends strongly on the antecedent morphology as evidenced by significant correlations between summer/winter shoreline response and the shoreline position at the start of each season. Beaches change as a result of changes in the wave conditions, and the weather and climate controls wave conditions. We surveyed two beaches in SW England and one beach in SW France every month for more than 15 years and analyzed these data to look, for the first time, at the connections between beach change, waves and climate along the Atlantic coast of Europe. Atmospheric indices are numbers that tell us about large-scale weather, and the North Atlantic Oscillation and the Western Europe Pressure Anomaly (WEPA) are powerful indices that describe the weather in the north-east Atlantic. We found that especially WEPA is strongly correlated with winter waves and beach change during the winter months for all three study sites. We also found that beach change over the summer and winter season depends very much on whether the beach is relatively healthy or depleted of sediment. Three beach profile data sets are used to investigate link between shoreline change, waves and climate along the Atlantic coast of EuropeWinter wave conditions and shoreline change are correlated with atmospheric indices North Atlantic Oscillation and Western Europe Pressure Anomaly, but uncorrelated to El Nino Southern OscillationAntecedent beach morphology is an important factor in determining summer and winter shoreline response

Automated summary

Beaches are highly variable environments and respond to changes in wave forcing, themselves modulated by climate variability. Winter wave conditions and shoreline variability are strongly linked to North Atlantic Oscillation and Western Europe Pressure Anomaly, but not to El Nino Southern Oscillation. The antecedent beach morphology is an important factor in determining summer and winter shoreline response.