The polar forcing via ion drag generates strong westward (sub-corotating) winds at peak velocities of around 1300 m s−1 near 82° latitude and ∼1600 m s−1 near 78° (not shown). In order to relate zonal wind velocities near the ionospheric peak to the degree of corotation of the upper atmosphere, Fig. 8 shows latitudinal profiles of the atmospheric angular velocity relative to Saturn’s rotational velocity, ω/ΩS. The solid black line displays the magnetospheric plasma angular velocity of Cowley et al. (2004) from which the electric field used in our simulations (Fig. 2) was derived. The solid blue line is the atmosphere’s diurnally-averaged angular velocity near the ionospheric peak.
strong westward (sub-corotating) winds
peak velocities
around 1300 m s−1
m s−1
Saturn
latitude
82°
°
strong westward (sub-corotating) winds
peak velocities
∼1600 m s−1
m s−1
Saturn
latitude
78°
°