  We propose the weak magnetic effect, which emerges in quark-gluon plasma
close to local thermal equilibrium as the dissipative correction to the quark
phase space distribution function, as a novel contribution to the observed
Lambda hyperon local spin polarization. With a finite field strength, which is
consistent with previous estimate of the magnetic field in heavy-ion
collisions, one is able to explain the experimentally observed Lambda local
spin polarization through all centrality classes. Moreover, the weak magnetic
effect plays an unambiguous role in the ordering between the second-order and
the third-order modulations of the Lambda local spin polarization in
experiments.
