Subtropical deserts form primarily through the action of circulating air currents known as Hadley cells.
The Role of Hadley Cells
Based on the provided information, deserts located in the subtropics owe their existence to the influence of atmospheric circulation patterns referred to as Hadley cells. These are large-scale atmospheric convection cells that transport heat from the equator to the subtropics.
The formation process begins in the tropics, as described by the reference:
- The sun is positioned directly overhead in the tropics, leading to intense heating of the air.
- As this air is heated, it absorbs water, becoming moist and humid.
- This warm, moist, humid air then rises vertically.
- The rising air column results in higher air pressures above it, simultaneously creating lower pressure (leaving a vacuum) at the surface below in the tropics.
The reference explicitly states that the "action of circulating air currents known as Hadley cells" derived from this process is responsible for the formation of deserts in the subtropical regions.
For further context on the atmospheric phenomenon, you can read more about Hadley cells.
