Two-way acoustic propagation measurements obtained along 200-m horizontal paths, a few meters below ice in the eastern Arctic, are used to estimate energy dissipation rate and momentum transfer between the ice and the ocean. Forward scattered sound propagating through the turbulent fluid of the boundary layer under ice produces characteristic scintillation patterns at the receivers which are interpreted in terms of the refractive index fine structure of the flow. Reciprocal travel time measurements yield information about the velocity variability along each acoustic path. By combining these two types of measurements, the contributions of sound speed and water-particle velocity fluctuations to forward acoustic scatter can be separated. For the particular case of the under-ice boundary layer, sound speed variability is negligible. Therefore, under the assumptions of a Kolmogorov inertial subrange and Taylor's frozen field hypothesis, the one-way and the reciprocal acoustical measurements provide two independent estimates of turbulent kinetic energy dissipation rate averaged over the propagation paths. Both these methods yield a value of 8¿10-8 W kg-1 6 m from the bottom of the ice for a 7-hour period during which the mean ice-relative velocity is 0.11 m s-1. Surface layer approximations then yield a value of 0.03 N m-2 for turbulent stress near the surface. The acoustical measurements also indicate that circulation around ice keels can cause horizontal ''lift forces'' of order 104 N. ¿ American Geophysical Union 1995