DIX Planetary Science Seminar

The classical circumplanetary disk (CPD) pattern is prograde - in other words, aligned with the Protoplanetary disk. Using 3D global hydrodynamic simulations, we show that when planet eccentricity is large enough, the CPD can become retrograde due to impact velocity relative to the background shear. Likewise, presence of strong turbulence also introduces constantly fluctuating impact velocities, leading to possible randomization of the CPD as well as migration torque. These chaotic torques tend to destabilize mean motion resonances, causing planet pairs to migrate into tighter orbits and become more prone to dynamical instabilities in the post-PPD phase. On the other hand, in regimes of low turbulence, accretion may be driven by MHD wind instead of turbulence. We show that the gas radial inflow structure in a windy disk can cause migration torque saturation and gap-opening process to be different from laminar disks, possibly producing distinct dust substructures in sub-millimeter observations.