15-year-long Adriatic hindcast: Sensitivity to atmospheric forcing

The Adriatic basin is narrow and elongated with numerous islands and surrounded in many parts by steep orography. Therefore ocean models of the Adriatic Sea should benefit from high-resolution atmospheric forcing that could properly account for orographic variations. We compare the results of long-term hindcasts obtained by using three different atmospheric reanalyses with different spatial resolutions. The CROCO ocean model (formerly ROMS_AGRIF) was configured on a relatively coarse 4 km grid, which we consider fine enough to observe the effects of different forcing resolutions, but still coarse enough that we were able to run multiple simulations in a manageable time. Initial and open boundary conditions were provided by CMEMS Mediterranean Sea Physics Reanalysis, and the model includes 36 freshwater sources. A thorough analysis of several run configurations revealed that spatial resolution should not be the primary criteria in choosing the right forcing, as atmospheric models can be subject to significant biases. These tend to strongly influence the results and sometimes even cause circulation reversals. Here we present the main differences between the runs and also evaluate each of them by comparing the results with satellite observations of sea surface temperature.