12. Bipolar Sprites: The Yin and Yang of Red Lightning
A unusual and interesting kind of red lightning event, bipolar sprites combine positive and negative electrical discharges in a single structure. Usually consisting of a brilliant, downward-propagating streamer at the top (the positive component) and upward-propagating branches at the bottom (the negative component), these intricate formations usually consist.
The bipolar character of these sprites offers a special view into the complex equilibrium of electrical charges in the top atmosphere. Strong positive cloud-to– earth lightning strikes are thought to start the positive streamers; the negative branches could be a reaction to the charge imbalance the first discharge generated.
Because bipolar sprites are rare and require fast, sensitive imaging tools, observing and researching them is difficult. These events, however, provide insightful analysis of the complicated interaction of positive and negative charges in the environment and the processes controlling sprite generation and spread.