At what latitude do the great deserts of the world typically line up?

The great deserts of the world are typically found around 30 degrees latitude, both north and south of the equator. This latitude is associated with the descending arm of the Hadley cells, which are large-scale atmospheric circulation patterns. Warm air rises at the equator, creating an area of low pressure. As this air moves towards the poles, it cools and sinks at approximately 30 degrees latitude. The descending air is dry because it loses much of its moisture as it rises, resulting in arid conditions and the formation of deserts.

This pattern is evident in many of the world's major deserts, such as the Sahara in Africa, the Arabian Desert, and the Sonoran Desert in North America. Each of these deserts is on or near the 30-degree latitude mark due to similar climatic conditions created by the Hadley cell circulation. The other latitudes listed—60 degrees, 15 degrees, and 45 degrees—do not correspond to the same prevailing climatic conditions conducive to desert formation. At 60 degrees, for instance, the air tends to be cooler and more humid, leading to forested and wetter environments rather than deserts.