  High-resolution imaging-spectroscopy movies of solar active region NOAA 10998
obtained with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish 1-m
Solar Telescope show very bright, rapidly flickering, flame-like features that
appear intermittently in the wings of the Balmer H-alpha line in a region with
moat flows and likely some flux emergence. They show up at regular H-alpha
blue-wing bright points that outline magnetic network, but flare upward with
much larger brightness and distinct "jet" morphology seen from aside in the
limbward view of these movies. We classify these features as Ellerman bombs and
present a morphological study of their appearance at the unprecedented spatial,
temporal, and spectral resolution of these observations. The bombs appear along
magnetic network with footpoint extents up to 900km. They show apparent travel
away from the spot along the pre-existing network at speeds of about 1 km/s.
The bombs flare repetitively with much rapid variation at time scales of
seconds only, in the form of upward jet-shaped brightness features. These reach
heights of 600-1200km and tend to show blueshifts; some show bi-directional
Doppler signature, and some seem accompanied with an H-alpha surge. They are
not seen in the core of H-alpha due to shielding by overlying chromospheric
fibrils. The network where they originate has normal properties. The morphology
of these jets strongly supports deep-seated photospheric reconnection of
emergent or moat-driven magnetic flux with pre-existing strong vertical network
fields as the mechanism underlying the Ellerman bomb phenomenon.
