GEOL 2207 Lecture Notes - Lightning, Cloud Base, Thunderstorm
Document Summary
Created by lightning: an electrical discharge through the air that heats the air to temperatures warmer than the surface of the sun. Heat causes the air to incandesce (glow) Path is instantly heated by lightning expanding to create shockwaves. Can be further classified by whether or + charge moves to the ground. Negative strikes: form from the cloud base and are more numerous. Positive strikes: are less frequent, much stronger form from thunderstorm anvil, most likely to start wildfire. Associated with freezing and collision of cloud droplets nd ice crystals (grauplin) When electrical potential between cg becomes great enough (breakdown potential), the air ionizes. Air becomes a conductor along the ionized path: known as the stepped latter. When it nears the ground, streamers of electron rises from tall trees to meet the step ladder: when connection is made, closing the circuit, electron flow in a massive current called the return stroke.
