Acoustic Noise Recorded by MERMAID Floats and its Relation to Ocean WaveClimate in the Mediterranean

Mobile Earthquake Recorder in Marine Areas by Independent Divers, or MERMAID floats, provide a unique dataset to probe the oceanic soundscape. MERMAID not only records arrivals from earthquakes at local to teleseismic distances, but also acoustic noise from various sources within the water column. Particular MERMAID floats are able to directly report acoustic noise power spectral densities (PSDs) with time, allowing for examination of the strongest source of acoustic noise, ocean waves. We make comparisons between PSDs recorded by MERMAID in the Mediterranean starting in 2021 and those predicted by calculating both primary and secondary microseism excitation associated with ocean wave model outputs. From these, the relative importance of the primary and secondary microseism mechanisms to acoustic power in the water column and the associated transfer functions can be examined, giving further insight into excitation of some of the strongest global geophysical signals and noise sources.