Warm air rises. Why, then, all year round there is snow in the mountains at an altitude of 4 km, and at an altitude of 10 km

Warm air rises. Why, then, all year round there is snow in the mountains at an altitude of 4 km, and at an altitude of 10 km, where passenger jet liners fly, the temperature is about -50 ° C.

Air pressure decreases with altitude. Therefore, as the air rises, it expands. And while expanding, he does work, spending part of his internal energy on it. This is the main reason for air cooling.