Earth’s atmosphere is a layered mixture of gases governed by temperature, pressure, chemistry, and energy. Explore its structure and composition, along with the physical processes that influence conditions from the surface upward.
The thermosphere exposes a limitation in the everyday meaning of temperature. Individual gas particles in its upper reaches can carry enough kinetic energy for a thermometer-like calculation to exceed 2,000°C. Yet an object placed among them would not be blasted as if it had entered a furnace. There...
Long after low clouds have darkened at sunset, delicate blue-white threads can remain luminous high above the horizon. These are noctilucent clouds, whose name means night-shining. They occupy the upper mesosphere near the mesopause, commonly around 76 to 85 kilometers above Earth, making them the...
Ascending through the troposphere usually means entering colder air. Cross the tropopause into the stratosphere, however, and that familiar trend eventually reverses: temperature increases with height. This broad vertical warming is the stratospheric temperature inversion, a defining feature of the...
The atmosphere has no rigid lid, yet most of its substance is crowded into a remarkably shallow region. Roughly three-quarters of its mass lies in the troposphere, the lowest layer, which reaches only about 8 to 18 kilometers above sea level depending on latitude and season. Compared with Earth’s...