  Peterson et al. [2009] intend to determine the NOx production of sprites and
blue jets from laboratory experiments. Sprite discharges are known to be
physically similar to streamer discharges at standard temperature and pressure.
However, streamer experiments that simulate geophysical discharges require
voltage pulses of one polarity, in contrast to the oscillating voltages of
Peterson et al. Furthermore, Peterson et al. make errors in their comparison of
current densities, sprite volumes and gas densities. Finally, there is a
calculation error of 6 orders of magnitude in an important result.
