  The eROSITA bubbles are detected via the instrument with the same name. The
northern bubble shows noticeable asymmetric features, including distortion to
the west and enhancement in the eastern edge, while the southern counterpart is
significantly dimmer. Their origins are debated. Here, we performed
hydrodynamic simulations showing that asymmetric eROSITA bubbles favor a
dynamic, circumgalactic medium wind model, but disfavor other mechanisms such
as a non-axisymmetric halo gas or a tilted nuclear outflow. The wind from the
east by north direction in Galactic coordinates blows across the northern halo
with a velocity of about 200 km s$^{-1}$, and part of it enters the southern
halo. This creates a dynamic halo medium and redistributes both density and
metallicity within. This naturally explains the asymmetric bubbles in both the
morphology and surface brightness. Our results suggest that our Galaxy is
accreting low-abundance circumgalactic medium from one side while providing
outflow feedback.
