  Recent Juno observations have greatly extended the temporal and spatial
coverage of lightning detection on Jupiter. We use these data to constrain a
model of moist convection and lightning generation in Jupiter's atmosphere, and
derive a roughly solar abundance of water at the base of the water cloud.
Shallow lightning, observed by Juno (Becker et al., 2020, Nature, 584, 55-58)
and defined as flashes originating at altitudes corresponding to pressure less
than 2 bars, is reproduced, as is lightning at a deeper range of pressures,
including those below the water cloud base. It is found that the generation of
lightning requires ammonia to stabilize liquid water at altitudes corresponding
to sub-freezing temperatures. We find a range of local water abundances in
which lightning is possible, including subsolar values of water--consistent
with other determinations of deep oxygen abundance.
