Final answer:
The region where belts of calm air occur between the trade winds and the westerlies is known as the Horse Latitudes. These latitudes are typically found at around 30 degrees latitude in both hemispheres.
Step-by-step explanation:
The region where belts of calm air occur in both the northern and southern hemispheres between the trade winds and the westerlies is known as the Horse Latitudes. These horse latitudes are typically found around 30 degrees latitude in both hemispheres. The air in this region is often calm and has little wind due to the downward motion of air masses.