Modeling of ships as a source of underwater noise

In this paper, a methodology is presented for modeling underwater noise emissions from ships based on realistic vessel activity in the Baltic Sea area. This paper combines the Wittekind noise source model with the Ship Traffic Emission Assessment Model (STEAM) in order to produce regular updates for underwater noise from ships. This approach allows the construction of noise source maps, but requires parameters which are not commonly available from commercial ship technical databases. For this reason, alternative methods to fill in the required information were necessary. Most of the parameters needed contain information which are available during the STEAM model runs, but features describing propeller cavitation are not easily recovered for the world fleet. Baltic Sea ship activity data was used to generate noise source maps for commercial shipping. Containerships and bulk cargo ships were identified as the most significant source of underwater noise, with a significant potential for increasing contribution to future noise emissions.