Travel-time measurements from an ocean acoustic tomography array deployed in the central Beaufort Gyre during 2016–2017 for the Canada Basin Acoustic Propagation Experiment (CANAPE) have been previously used to test the accuracy of the internationally accepted sound-speed equation (TEOS-10) Vazquez et al. (2023), J. Acoust. Soc. Am. 154, 2676–2688 concluding that TEOS-10 gives sound speeds at high pressure (1000 m) and low temperature (0°C) that are too high by 0.14–0.16 m s−1. Here, a revised seawater sound-speed equation is developed that is consistent with the CANAPE travel times. First, a revised seawater sound speed equation is formulated using maximum a posteriori estimates based on laboratory data, defining the priors of the system in a reproducible manner. This equation is subsequently updated by fitting to the CANAPE travel times through iterative least-squares. CTD casts conducted in the Arctic are employed to assess the discrepancies between the revised sound-speed equation and other sound-speed equations. While including the deep acoustic transmissions corrects the portion below 1000 m depth, it also slightly corrects an additional anomaly between 100 and 300-m that corresponds to temperatures as low as −1.8°C.
Vazquez et al. (Wed,) studied this question.