Mean free length
Atmospheric temperature
Number of ions
Size and charge per ion
increased inductance
increased reactance
increased power loss
all of the above
humid weather
dry weather
winter
hot summer
much less than that needed in fair weather
much higher than that needed in fair weather
equal to that needed in fair weather
none of the above
produces a pleasing luminous glow
makes line current sinusoidal
works as a safety valve for surges
ozone gas is produced