Coastal impacts of Storm Gloria (January 2020) over the north-western Mediterranean

Abstract

The ocean component and coastal impacts of Storm Gloria, which hit the western Mediterranean between 20 and 23 January 2020, are investigated with a numerical simulation of the storm surges and wind waves. Storm Gloria caused severe damages and beat several historical records, such as significant wave height or 24 h accumulated precipitation. The storm surge that developed along the eastern coasts of the Iberian Peninsula, reaching values of up to 1 m, was accompanied by wind waves with a significant wave height of up to 8 m. Along the coasts of the Balearic Islands, the storm footprint was characterised by a negligible storm surge and the impacts were caused by large waves. The comparison to historical records reveals that Storm Gloria is one of the most intense among the events in the region during the last decades and that the waves' direction was particularly unusual. Our simulation permits quantification of the role of the different forcings in generating the storm surge. Also, the high spatial grid resolution down to 30 m over the Ebro Delta allows determination of the extent of the flooding caused by the storm surge. We also simulate the overtopping caused by high wind waves that affected a rocky coast of high cliffs (∼15 m) on the eastern coast of Mallorca.