- Above the subtropical highs in the Northern Hemisphere, and below the subtropical highs in the Southern Hemisphere, winds blow from the west towards the east. These winds are thus called westerly winds, after the direction from whence the winds come. The westerlies generally blow between 30 ° and 60 ° latitude in both the Northern and Southern hemispheres. The higher one travels into the atmosphere, the more noticeable these westerly winds are.
- the sub-tropical high pressure belt of the oceans of North Pacific and North Atlantic oceans is known as horse latitudes. This is a belt of weak variable winds and frequent calms.
- Doldrum: the quite zone at ITCZ is called the doldrums. The air appears to be stagnant in this belt. Earlier ships used to get stuck in this region because of the absence of the wind.
- Jet streams are high speed winds that occur in narrow bands of upper air westerlies. The width of this air band can be 160-480km wide and 900-2150m thick, with core speed exceeding 300km/hr. such is their strength that aircraft routes which run counter to jet movements are generally avoided. Jets are coincident with major breaks in the tropopause.
BPCS Notes brings Prelims and Mains programs for BPCS Prelims and BPCS Mains Exam preparation. Various Programs initiated by BPCS Notes are as follows:-