2023 November Storm in The Port of Klaipeda; Why was The Port Closed?

Abstract

This study examines the impact of storm surges, infragravity waves, wider area seiches and natural harbour oscillations (harbour seiches) on port operations in the Baltic Sea, with a particular emphasis on the Port of Klaipėda, all during the severe storm that occurred from November 22–24, 2023. The study examines the interplay between meteorological factors, such as changes in air pressure and wind speed and direction, and the coastal geography of the area. Wind speeds during the storm reached a maximum of 29.7 m/s, and air pressure dropped for f ~ 50 hPa, with a corresponding sea level rise of approximately 40 cm due to the combined effects of storm surges and long waves. The research findings indicate that it was precisely long waves, which were generated offshore and amplified by the port's distinctive resonance characteristics and coastal topography, that were the primary cause of operational disruptions, creating hazardous conditions that necessitated the closure of the port. The port's elongated and narrow inlet played a pivotal role in the amplification of these waves, rendering it particularly vulnerable to resonance-induced oscillations. The research yielded several key findings, including identifying long waves (long ocean waves, wider area seiches, harbour seiches, and infragravity waves) with periods ranging from 12 to 13 h to 2–4 min, which posed significant risks to vessels moored at the port. Furthermore, the occurrence of simultaneous sea level fluctuations between Klaipėda and Karlshamn indicated the presence of seiches with period of 12,4 h across the Baltic Sea, thereby further complicating port operations. These results underscore the critical need for improved forecasting and mitigation strategies to enhance the safety and efficiency of port activities during severe weather events.