Circulation of Atmosphere

• Atmospheric circulation, any atmospheric flow used to refer to the general circulation of the Earth and regional movements of air around areas of high and low pressure.
• On average, this circulation corresponds to large-scale wind systems arranged in several east–west belts that encircle the Earth.
• The pattern of the movement of the planetary winds is called the general circulation of the atmosphere.
• The general circulation of the atmosphere also sets in motion the ocean water circulation which influences the earth’s climate.

Katabatic Wind 

• During the night the slopes get cooled and the dense air descends into the valley as the mountain wind. These breezes occur mostly during calm and clear weather.
• The cool air of the high plateaus and ice fields draining into the valley is called Katabatic Winds 

ITCZ

• Inter Tropical convergence zone (ITCZ) is a low pressure zone located at the equator where trade winds converge and so it is a zone where air tends to ascend. 
• In july the ITCZ is located around 200 N - 250 N lattitudes ( over the Gangetic plain), sometimes called the monsoon trough, this monsoo trough encourages the development of thermal low over north and northwest India. 

Jet Streams 

• Jet streams are the strong air streams present in the upper troposphere. 
• Jet streams occur in both the Northern and Southern Hemisphere. 
• They are relatively narrow belts of swift moving winds having velocity in the range of 100km/hr to 900km/hr.  
• Jet streams follow curved and meandering path and such path is because of corollis effect and due to the tendency of large scale system to conserve the angular momentum. 

Trade Winds

• These winds blow in 10-30 degrees latitude in the northern and southern hemispheres.
• These are permanent east to west prevailing winds that flows in the earth’s equatorial region.
• The winds help ships travel west, and they can also steer storms such as hurricanes, too