Answer:
thermosphere: The layer of the Earth's atmosphere directly above the mesosphere and directly below the exosphere.
troposphere: The lower levels of the atmosphere extending from the earth's surface up to the tropopause. It is characterized by convective air movements and a large vertical temperature change.
Explanation:
The Earth's atmosphere is typically split into five layers, from bottom to top: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The atmosphere is held in place by gravity, which decreases exponentially with distance from the Earth's center, hence air pressure also decreases exponentially from the surface to the top of the exosphere where the last and lightest molecules escape into the interstellar medium.
