Plain English Meaning

Earth's atmosphere is built in layers, like a stack. Each layer behaves differently in terms of temperature, air density, and what happens inside it. Pilots fly almost entirely within the lowest layer, where weather lives.

Full Definition

The layered organization of Earth's atmosphere, in which the gaseous envelope surrounding the planet is divided into distinct horizontal layers based on temperature behavior, composition, and altitude. The principal layers, from the surface upward, are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The troposphere extends from the surface to roughly 36,000 feet at mid-latitudes and is where nearly all weather occurs. The stratosphere lies above it and contains the ozone layer.

Context Anchor

Seen at the start of weather and aircraft performance discussions, especially when explaining pressure, temperature, , and .