Example of some of the streamlines surrounding the embedded planet. Three types of streamlines are shown: one that misses the CPD completely [(1) blue], one that enters into the region of the CPD for less than an orbit [(2) orange], and one that ends up in the CPD [(3) red]. The solid lines represent forward integration from the initial conditions (black circles), while the dashed lines represent backward integration from the initial conditions. The coloured triangles show the location from which the chemical calculation is initialised. The host star is the black square. The x-axis corresponds to the radial distance along the axis passing through the host star and the embedded planet, centred here on the embedded planet. The y-axis runs perpendicular to the host star–planet axis and the z-axis extends from the midplane to heights above the disk. x > 0 corresponds to a distance farther from the host star than the planet, while y > 0 corresponds to the leading side of the planet’s orbit.