English: Example of vertical cross-section of the pressure pattern, in colors, radiated by a pair of interacting ocean wave trains of period around 10 s. The sea surface elevation, plotted as a blue line around z = 0 is the sum of the elevations of the two wave trains and has a wave group structure. (A) The periods of the two

wave trains are 10 s and 9.66 s (B) 10 s and 9.94 s. Note that the vertical displacement of the sea surface is strongly exaggerated in order to make waves visible. A realistic ocean wave field includes many wave trains and thus all possible pairs of interactions radiating acoustic waves in all directions θa . As the two periods of the wave train get closer, from (A) to (B), the lengths of the groups get larger and the angle θa becomes smaller. This paper focuses on the radiated power as a function of θa .

See De Carlo et al. (2020 https://doi.org/10.1093/gji/ggaa015 ) for more details.