When air moves into upper atmosphere it becomes what?

When air moves into the upper atmosphere, it generally becomes less dense and cooler due to the decrease in atmospheric pressure with altitude. As it ascends, the air expands, which can lead to the formation of clouds and precipitation if the air contains sufficient moisture. Additionally, the composition of the air may change slightly, as different layers of the atmosphere can have varying concentrations of gases. Ultimately, this process is crucial for weather patterns and climate dynamics.