Influence of macroscale and regional circulation patterns on low- and high-frequency sea level variability in the Baltic Sea

• Published in: Theoretical and Applied Climatology
• Main Authors: Bednorz, Ewa, Tomczyk, Arkadiusz M.
• Other Authors: National Science Centre, Poland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: Atmospheric Science; Arctic; Norwegian Sea; North Atlantic; North Atlantic oscillation
• Online Access: http://dx.doi.org/10.1007/s00704-020-03500-0; http://link.springer.com/content/pdf/10.1007/s00704-020-03500-0.pdf; http://link.springer.com/article/10.1007/s00704-020-03500-0/fulltext.html

Abstract The atmospheric impact on sea level variability in the Baltic Sea on different time scales was investigated. The Northern Hemisphere teleconnection patterns, namely, the North Atlantic Oscillation (NAO), Arctic Oscillation (AO) and Scandinavia (SCAND) patterns, were employed, and a strong but non-stationary relationship was found. The SCAND appeared to be most relevant to the mean monthly Baltic Sea level variations throughout the year. A negative correlation indicates that a cyclonic centre over Scandinavia in the negative phase of SCAND enhances western circulation, which then triggers water inflow through the Danish straits. The AO annular mode reveals a positive and slightly stronger relationship with the Baltic Sea level than the NAO. The rapid increases in the Baltic Sea level recognized in this study, namely, those exceeding 24 cm within a 5-day period, mainly occur in the cold season. These increases are associated with the development of specific synoptic conditions in the Euro-Atlantic region, characterized by a shift from high to low pressure over Europe and a rapid increase in the pressure gradient during the week preceding the sea level rise. Rapid increases are associated with cyclones coming from the North Atlantic, which move 1500–2000 km during the week preceding the strong rise of the Baltic waters. The cyclone tracks may be shifted north or south, while the final position is over the Norwegian Sea.