What is the electrical phenomenon characterized by negative charges moving downward and positive charges moving upward?

The electrical phenomenon where negative charges move downward and positive charges move upward describes the process involved in lightning. During a thunderstorm, the buildup of electrical charges occurs as a result of interactions between particles in the atmosphere, typically within clouds. Negatively charged particles accumulate at the bottom of the cloud while positively charged particles rise to the top. This creates a significant voltage difference that can lead to a discharge of electricity in the form of lightning, which represents the movement of these charges.

Thunder, while associated with lightning, is actually the sound produced by the explosive expansion of air heated by the lightning strike. Static electricity refers to the buildup of charge on an object's surface, often from friction, and does not involve the movement of charges over long distances like in lightning. Electric current pertains to the flow of electric charge through a conductor, which is a broader concept that doesn't specifically describe the dramatic and instantaneous discharge seen in lightning. Thus, lightning is the specific phenomenon that encompasses the movement of charges as described in the question.