Long-term storminess and sea level variations on the Estonian coast of the Baltic Sea in relation to large-scale atmospheric circulation

Variations and trends in storminess (number of storm days), and mean and maximum sea levels were analysed along the Estonian coast during the last century. An increase in storminess was detected at the Vilsandi and Sõrve stations, although inhomogeneities in the wind data make the trends less reliab...

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Bibliographic Details
Published in:Estonian Journal of Earth Sciences
Main Authors: Jaak Jaagus, Ülo Suursaar
Format: Article in Journal/Newspaper
Language:English
Published: Estonian Academy Publishers 2013
Subjects:
Online Access:https://doi.org/10.3176/earth.2013.07
https://doaj.org/article/a75f7df531244591be227c629248eb57
Description
Summary:Variations and trends in storminess (number of storm days), and mean and maximum sea levels were analysed along the Estonian coast during the last century. An increase in storminess was detected at the Vilsandi and Sõrve stations, although inhomogeneities in the wind data make the trends less reliable. Mean sea level trends depend on the post-glacial isostatic land uplift, which is different in different parts of Estonia. After eliminating the influence of the uplift, the estimated sea level rise was 2.2–3.2 mm yr–1 during 1950–2011, which was higher than the global mean (1.9 mm yr–1). The majority of increases in storminess and sea level have been observed during the cold half-year (November–March). An increase in annual maximum sea level has been much higher than in mean values, which indicates a strong increase in the flooding risk. Atmospheric circulation is closely related to the frequencies of storms and high sea level events, especially during the cold season. Variables describing the intensity of zonal circulation (westerlies), such as the Arctic oscillation and North Atlantic oscillation indices, and the frequency of the circulation form W according to the Vangengeim–Girs classification are highly correlated with storminess and sea level on the Estonian coast during 1950–2011. Negative correlations appeared in case of the circulation form E and the SCAND index.