Mean spin angular frequency of the planet’s surface as a function of disc orbital radius for different planet masses. The Stokes number of the pebbles in these simulations was 0.1. The left panel shows the spin of the planet’s surface due to PA in the presence of an atmosphere. The right panel shows the spin in the absence of an atmosphere, with the spin with an atmosphere represented by transparent lines for direct comparison. In general, the atmosphere reduces the amount of spin that reaches the surface. The larger the planet, the stronger the spin reduction. For planets as small as 0.5 Earth masses, the atmosphere will absorb all spin. Additionally, the larger the planet, the larger the retrograde spin domain is, both with and without an atmosphere. Finally, as the spin crosses from retrograde to prograde, there is a small domain in which the atmosphere increases the amount of spin. This suggests a slight asymmetry between the damping of prograde and retrograde spin contributions.