How jet stream occurs?

Answer 1

Air circulating north and south of the subtropical high pressure zones generally blows in a westerly direction in both hemispheres, giving rise to the prevailing westerly winds. These westerly moving air masses again become heated and start to rise, creating belts of subpolar lows.

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.

Answer 2

Jet streams occur in the Northern Hemisphere in the summer months. These jet streams for in tropical regions and flow from east to west.

Answer 3

They occur at the boundaries between the first, second, and third wind systems