Evaluation of the ERA* ocean forcing product under storm surge conditions in the Adriatic Sea

Storm surges in the Adriatic Sea are periodic extreme weather events that cause high economical losses and endanger human lives. These events are caused by an atmospheric pressure depression and persistent south-easterly winds (Sirocco). This work focuses on further developing and verifying an enhanced ocean forcing product (ERA*) in the Mediterranean Sea, with the aim to improve the storm surge prediction capabilities in the Adriatic Sea region. The ERA* is a corrected ERA-Interim reanalysis product (ERAi) provided by the European Centre for Medium-range Weather Forecasts (ECMWF). A scatterometer-based correction, using high-resolution ocean stress-equivalent winds (U10S) from a scatterometer constellation is proposed to reduce ERAi local U10S biases. Since the local biases are relatively persistent over time, and their persistence is regionally dependent, ERA* has several configurations, which consist of different temporal windows over which the scatterometer-based corrections are applied. The accuracy of the product is being evaluated against an independent 25-km resolution U10S product from the Chinese HY-2A scatterometer HSCAT. [...]