What phenomenon causes lightning during thunderstorms?

Lightning during thunderstorms is primarily caused by the discharge of electricity between charged regions within the storm. Thunderstorms develop when there is a significant separation of electrical charges within the cloud, typically due to the collision of ice crystals and water droplets, which leads to the transfer of electrons. This creates positively and negatively charged areas within the cloud.

As these charges build up, the electrical potential increases until it becomes strong enough to overcome the resistance of the air. This results in a sudden discharge of electricity in the form of lightning. The rapid movement of electrons creates a pathway for the electrical charge to flow, resulting in the bright flash of lightning that we observe.

Understanding the process of charge separation and discharge helps clarify the core reason for lightning formation, distinguishing it from other atmospheric phenomena that may influence weather, such as air pressure changes or wind movement, which are not the primary causes of the electrical discharges associated with thunderstorms.