Listening to the raindrops from underwater for weather and climate

Jeffrey A. Nystuen is a pioneer in using the passive acoustic method to measure oceanic rainfall. Under Nystuen’s efforts, a self-contained passive acoustic recording device called the acoustic rain gauges were deployed all over the world, from a brackish pond in Florida, Carr inlet in Puget Sound, Crater Lake in Oregon, BioSphere II in Arizona, then to the South China Sea, the Pacific Ocean, the Taiwan strait, the Ionian Sea in Greece, the Aleutian Islands and ocean station Papa. This simple device records long-term spectra of sound pressure levels with minimum data screening, could detect the presence of oceanic rainfall, and provide estimates of rain rate and surface wind speed. Nystuen’s inspirational works over the past three decades set an example and path for future scientists and engineers to foster curiosity, pursue exploration and make discoveries.