The interactions of Henry E. Bass with the National Research Council in Canada.

Interactions between researchers at NRC and Bass span a period of more than 30 years during which many research areas of mutual interest were explored. This paper presents an overview of Bass’ research in atmospheric sound propagation during this period and the synergistic collaborations that developed with his friends and colleagues at the NRC. Early work began with the study of relaxation in gases and absorption of sound in the atmosphere. This expanded to include sound propagation above a finite impedance ground, the effects of refraction and atmospheric turbulence, and the development of fast numerical codes to predict long‐range sound propagation. The close collaboration and enduring friendships that we valued so much were forged over the years through many interactions, such as the numerous joint field experiments trudging through muddy fields, working in subzero temperatures, or suffering the blistering desert heat. Throughout, Bass was a driving force, and his contributions will fuel research for ...