  Electron-positron pair creation near sub-Eddington accretion rate black holes
is believed to be dominated by the Breit-Wheeler process (photon-photon
collisions). The interacting high energy photons are produced when unscreened
electric fields accelerate leptons either in coherent, macroscopic gaps or in
incoherent structures embedded in the turbulent plasma flow. The latter type of
acceleration results in a drizzle of pair production sourced by photons from
the background radiation field whose energies are near the pair-production
threshold. In this work, we use radiation GRMHD simulations to extend an
earlier study of pair drizzle by Moscibrodzka et al. We focus on
low-magnetization (SANE) accretion onto supermassive Kerr black holes and
consider radiation due to synchrotron, bremsstrahlung, and Compton upscattering
processes. We confirm that pair drizzle in M87 is sufficient to keep the
magnetospheric charge density orders of magnitude above the Goldreich-Julian
density. We also find that pair production peaks along the jet-disk boundary.
