2012 – Shipping Noise in the Philippine Sea
Shipping noise is an important part of the ocean 'environment', and presents interesting modeling problems.
The Philippines Sea is chosen as an example of a moderate sized ocean basin for the calculation of noise directionality. The upper left shows the elevation with the color bar giving negative elevations in meters. Green is also used for land. Shipping noise source level densities, at 50 Hz, are plotted in the upper right and are indicative of shipping lanes. The colors represent dB re: 1 microPa2 /Hz @ 1m/m2. A virtual receiving array is located in the center of the basin.
The calculated noise directivity is plotted versus bearing and elevation angle for a hard (reflective) ocean bottom, and for a soft (absorptive) bottom. Energy from near surface sources, over slopes, is seen in a range of elevation angles, around zero degrees. Differences between the two cases clearly show the importance of the ocean bottom reflectivity.