Acoustic propagation in the Connecticut River at low-to-mid frequencies

Abstract

An estuary is a constrained environment which often hosts a salt wedge, the stratification of which is a function of the tide's range and speed of advance, river discharge volumetric flow rate and river mouth morphology. A field experiment was carried out in the Connecticut River in June 2017, one goal of which was to investigate the low-to-mid-frequency acoustic propagation characteristics of the riverine salt wedge as well as the plume outside the river mouth. Linear frequency-modulated (LFM) acoustic signals in the 500–2000 Hz band were collected during several tidal cycles. Data-model comparisons demonstrate the degree to which this highly energetic environment impacts acoustic propagation; dominant mechanisms are sound speed stratification, boundary interaction, flow noise, and background noise.