Effect of nonlinear internal waves on midfrequency acoustic propagation on the continental shelf

Packets of nonlinear internal waves and strong sound‐speed variability due to neutrally buoyant intrusions were measured in detail using a towed conductivity, salinity, pressure (CTD) chain. The measurements were taken in October 2005, on the continental shelf south of Rhode Island. Acoustic propagation through the measured sound‐speed field is modeled. The waves in October are qualitatively different from the more familiar summertime nonlinear waves. Further measurements using the CTD chain will be made in the summer of 2006, in association with acoustic propagation measurements.