ASTRO-110 Lecture Notes - Lecture 13: Ionosphere, Thermosphere, Lithosphere
Document Summary
Conduction transfers heat between solid objects in contact with each other. This is how heat is lost through a planet"s lithosphere. Convection occurs when material can flow and temperature increases with depth. The hotter material rises and the cooler material falls, causing heat to flow upward. Convection carries heat away faster than conduction and takes place below the lithosphere, in the plastic mantel and in the fluid parts of planetary cores. Convection has important consequences both under a planet"s surface and above it. Tectonics and volcanism: tectonics are the result of internal forces on the lithosphere, and are largely driven by convection in the mantle beneath the lithosphere. Volcanism occurs when molten rock and gas escape through a planet"s lithosphere. Volcanism also plays a key role in creating a planet"s atmosphere through outgassing. Planetary atmospheres: like a planet"s interior, its atmosphere is also divided into layers. Bottom to top: troposphere (convection) --- greenhouse.
