The circulation pattern discussed above is mainly true on the surface movement. The atmosphere, like the oceans, have differences throughout the air column which cause changing weather. For example, when warmer air lies above polar air it, causes wind to blow parallel to where they meet. This produces a "jet" of strong air on a continuous basis referred to as the "Jet Stream."

Atmospheric circulation is further complicated by the distribution of land and water masses on the surface of the Earth and the topography of the land. The oceans are the source of moisture and the elevation of the land surface helps control where moist air will rise. Climatic zones depend not only on latitude, but also on the distribution and elevation of land masses. In general, however, most of the world's desert areas occur along the mid-latitudes where dry air descends along the mid-latitude high pressure zones.