Software tools for the simulation of oil spills at sea

This thesis aims at investigating the potentialities of two software tools performing the simulation of the transport and fate of oil spilled at sea: ADIOS2 and the WebGNOME codes, both made freely available by the US NOAA. ADIOS2 gives the oil budget evolution of the spill, that is, it solves the mass balances of the oil present in the different sea compartments. On the other hand, the WebGNOME tool is capable of both solving the oil budget and visualizing the oil slick trajectory. What comes out from the investigation carried out in this thesis is that ADIOS2 is not capable of handling a complete simulation, because it limits the simulation time to 5 days after the start of the spill. Instead, WebGNOME compensates for this lack, allowing to extend the simulation time up to 30 days. By taking a look at the images of the oil slick produced by WebGNOME, it emerges that from day 20 to 30 no major change is seen in the oil slick location. During the first 20 days after the spill, oil beaching occurs on both the northern shoreline and the southern islands of the Santa Barbara Channel, with a total amount of stranded oil equal to 4,800 m3, which accounts for 25 % of the spill. Due to the immediate start of evaporation, 28 % of the oil is transferred from the sea to the atmosphere. At the end of the simulation, floating oil accounts for 6,500 m3, that correspond to 40 % percent; the oil remaining on the sea surface is majorly placed in the outer west side of the Santa Barbara Channel, where it is quite stable, according the last 10 days of the simulation there are negligible changes in the oil budget. It can be claimed that the simulation time of 30 days is sufficient to describe the fate and the transport of the oil slick. In conclusion, the WebGNOME code, which is simple and intuitive to use, requires a limited amount of data, and has short computational times, seems a tool suitable for a preliminary analysis of the consequences of oil spill events at sea.