Coastal wave conditions in the Ionian Sea during the Medicane Ianos (2020).

An intense Mediterranean tropical-like cyclone (Medicane) known as Ianos developed in the central-eastern Mediterranean Sea in mid-September 2020. The parent cyclone of Ianos initially formed on 14 September and strengthened on 15-16 September. Ianos acquired its tropical characteristics mainly on 17-18 September and it began to gradually lose its energy on 19-20 September while it finally dissipated on 21 September. Although Ianos affected several Mediterranean areas, it significantly influenced Greece with strong winds, high waves, storm surge, coastal inundation, heavy rainfall, flash floods, and landslides, thus having severe socioeconomic implications including four deaths and extensive damages. The impact of Ianos on the sea state was very intense, especially across the coastal areas of the Ionian Sea where the cyclone was characterized by its maximum winds reaching even Category 2 of the Saffir-Simpson scale. Moreover, high waves were observed in the coastal areas of the Ionian Sea during the passage of Ianos. In this framework, this study investigates the coastal wave conditions during Ianos in the Ionian Sea using the open-source tool DNORA (https://github.com/KonstantinChri/dnora) to dynamically downscale the ERA5 reanalysis data applying the spectral wave model SWAN. We use high-resolution bathymetry from the EMODNET database. We analyze the wave conditions using integrated wave parameters such as significant wave height and wave periods as well as wave spectrum. Particular focus is given to the evolution of the 2D wave spectrum during the Medicane Ianos. Preliminary results indicate that such extreme atmospheric events can lead to rapid growth of wind sea conditions with a significant impact on coastal areas.