Is lightning AC or DC? If it is DC then are the clouds plus, ( + ) and the Earth minus, ( - ) or the reverse? If it is AC then what is the Hertz? Is it high voltage or high current or both? Inquiring minds want to know. ;-)
Lightning is DC
A novice answers:
DC, earth has a ton of free electrons (-) to migrate to the + charge developed by the convection in the cloud.
Hertz is the term for the unit 1/sec. the number of events “per second”. It is independent of voltage (potential difference) or amps (current). See V=IR. It’s the speed of the flip-flopping of the sinusoidal electronic ‘waveform. Thus, the electrons in your homes electric wires aren’t really moving like water in a steam, but oscillating back & forth. Tesla beat Edison on the AC/DC selection debate. Niagara Falls had something to do with that development, there may be a movie about it. If memory serves.
It Is not that simple, the top of the cloud is different from the bottom of the cloud. I think the strike starts at the cloud which goes down part way and then the strike come up from the ground to the first part. Also the strike can go up from the bottom to the top. Also the strike can go up beyond the cloud top. A person more into this could give a much better explanation.