  We have performed a series of numerical experiments aimed at studying the
activation of Kerr black holes (BHs) by advection of small scale magnetic
fields. Such configurations may potentially give rise to the formation of
quasi-striped Blandford-Znajek jets. It can also lead to enhanced dissipation
and generation of plasmoids in current sheets formed in the vicinity of the BH
horizon, which may constitute a mechanism to power the hard X-ray emission seen
in many accreting BH systems (a la lamppost models). Our analysis suggests that
formation of quasi-striped jets with significant power may be possible provided
loops with alternating polarity having sizes larger than $\sim 10 r_g$ or so
can be maintained (either form sporadically or advected from outside) at a
radius $\lesssim 10^2 r_g$. This conclusion is consistent with recent results
of general relativistic force-free simulations. We also find that the accretion
dynamics exhibits cyclic behaviour in MAD states, alternating between high
accretion phases and quenched accretion phases during which the magnetosphere
becomes force-free out to radii $\gtrsim 10r_g$. We suggest that such a
behaviour should lead to notable variations of the observed luminosity and
image of the inner disc (BH shadow image). Finally, we find that the transition
between accreted loops on the BH gives rise to the formation of current sheets
and energetic plasmoids on the jet boundary during intermittent periods when
the jet becomes inactive, in addition to an equatorial current sheet that forms
during peaks in the jet activity.
