Answer:
Vertical mixing only occurs in b) Troposphere
Step-by-step explanation:
- The troposphere is the sphere that is characterized by vertical mixing of air masses and air currents. As a result of the turbulence created in top layers of air.
- Here the uneven heating and cooling of land and oceans create convection currents to rise upwards and create up and downward movement of with environmental lapse rate and averages 6.5 ºC/km. This helps to push the troposphere boundary upward.
- The planetary boundary of motion creates such type of layer of air that moves through the poles and rising air stop at the tropopause as its the region or zone of mixing of air currents as all convective activity stops here.