Tracing storminess variability through seabed sediments in Puck Bay, southern Baltic Sea

Storms have severe impacts on coastal communities and infrastructure. The southern Baltic Sea coast is particularly vulnerable to storm surges, as it predominantly features barrier-type coast, and extensive areas of coastal lowlands are situated within 1.5 m above sea level. Due to the short instrumental record, our knowledge of the complex issue of storminess is relatively limited. Therefore, it is very important to extend the timespan of storm activity records through the use of geological proxies. The variability of sediment grain size and benthic diatom species alien to the muddy sediments of the Puck Bay were used to reveal storm periods. This study presents a record of 21 storm periods dating back approximately 4700 years b2k. Particularly severe and frequent storms occurred during the transition from the Medieval Warm Period to the Little Ice Age (LIA), during the main phase of the LIA and the transition from the LIA to modern times. LIA storms were recorded in seabed sediments not only due to higher hydrodynamics, but also due to niveo-aeolian sand transport on sea ice during winter storms. Fourier spectral analysis shows a cyclic occurrence of storminess, with the most common frequencies of around 21–26, 59–74, 526–591, and 1180 years. These results are in good agreement with periodic variations in the atmospheric circulation over the North Atlantic, which are most likely related to variations in regional total solar irradiance.