Articles | Volume 17, issue 9
Brief communication
25 Sep 2017
Brief communication |  | 25 Sep 2017

Brief communication: Characteristic properties of extreme wave events observed in the northern Baltic Proper, Baltic Sea

Jan-Victor Björkqvist, Laura Tuomi, Niko Tollman, Antti Kangas, Heidi Pettersson, Riikka Marjamaa, Hannu Jokinen, and Carl Fortelius

Abstract. A significant wave height of 7 m has been measured five times by the northern Baltic Proper wave buoy in the Baltic Sea, exceeding 8 m twice (2004 and 2017). We classified these storms into two groups by duration and wave steepness. Interestingly, the two highest events exhibited opposite properties, with the 2017 event being the longest storm on record. This storm is also the first where the harshest wave conditions were modelled to occur in the western part of the Baltic Proper. The metrics quantifying the storm's duration and steepness might aid in issuing warnings for extreme wave conditions.

Short summary
We studied the highest wave events in the Baltic Sea using wave measurements available since 1996. Going beyond classifying them based solely on the maximum wave height, we found that they can be divided into two groups based on, for example, the length of the storm. Two of the severest storms show different behaviour, with the most recent (in 2017) being the longest on record. We hope this more in-depth description of the storms will aid in the issuing of warnings for extreme wave conditions.
Final-revised paper