Infrasonic observations of open ocean swells in the Pacific: Deciphering the song of the sea

Abstract

Microbaroms are infrasonic waves generated by nonlinear interactions of ocean surface waves traveling in nearly opposite directions with similar frequencies. Such interactions commonly occur between ocean waves with ∼10 s periods, which are abundant in the open oceans and correspond to the observed 0.2 Hz infrasonic spectral peak. Microbarom observations from Hawai'i during 2002–2003 show a relationship with storm and ocean wave activity in the Pacific. Seasonal patterns of observed microbarom arrival azimuths are affected by the size and distribution of swells, by the dominant wind directions in the atmosphere, and by topographic shadowing.