Convective and non-convective nature of Balearic meteotsunamis: a 50-year historical review
摘要
Meteotsunamis, locally known as rissaga in the Balearic Islands, are significant sea-level oscillations induced by atmospheric disturbances, with amplitudes and frequencies comparable to seismic tsunamis. The port of Ciutadella (Menorca) is a recognized hotspot for meteotsunami occurrence. This study presents a 50-year analysis of 191 meteotsunami events recorded in Ciutadella between 1975 and 2025, focusing on the distinction between the convective and non-convective nature of the pressure disturbances that triggered the meteotsunami event and their implications for predictability and risk assessment. Events were classified using historical records, in-situ barographic and sea-level observations, satellite imagery, and lightning data. Statistical analyses explored relationships between atmospheric drivers, wave amplitude, amplification factor, and forecast performance. Results show that non-convective meteotsunamis are typically triggered by internal gravity waves, producing relatively regular and moderate pressure fluctuations. In contrast, convective events are associated with abrupt pressure jumps and tend to produce the most extreme sea-level oscillations, exceeding 3–4 m in some cases, such as the catastrophic events of June 1984 and June 2006. Although non-convective events are more frequent, the most intense ones are predominantly convective: all meteotsunamis with amplitudes > 220 cm are linked to convective disturbances. Forecasting skill varied by event type: a fully realistic high-resolution ocean-atmosphere modelling system (BRIFS) performed relatively better for convective cases than for non-convective cases, whereas a reduced-physics method (TRAM) was more accurate for non-convective cases. These results underscore the need to combine complementary modelling systems, as no single approach consistently performs well across all types of triggering mechanisms. This study provides the most extensive meteotsunami dataset for the Balearic Islands to date and offers a novel framework for understanding the contrasting dynamics and characteristics of both types of events. The results support the development of improved early-warning systems and more effective coastal risk mitigation strategies in vulnerable regions.