Energy redistribution from the Equator to the Poles by Winds Flashcards
What are winds?
Large scale movements of air caused by differences in air pressure
What are differences in air pressure caused by?
Differences in atmospheric heating between the Equator and the poles
What are winds part of?
Global atmospheric circulation cells
What are the features of global atmospheric circulation cells?
They have a body of warm rising air which creates an area of low pressure, and a body of cool falling which creates an area of high pressure
Where do winds move?
From the areas of high pressure to the areas of low pressure
What are the three main types of global atmospheric circulation cells?
Hadley, Ferrel and Polar Cells
What happens at the equator?
Sun warms the Earth, which transfers heat to the air above, causing it to rise. Rising air creates low pressure, clouds and rain
What is the low pressure zone of rising air called?
The Intertropical Convergence Zone (ITCZ)
What happens as the air rises?
It cools and move out to 30° North and South of the Equator
What happens 30° North and South of the Equator?
The cool air sinks, creating high pressure. Sub-tropical jet streams are found here (jet streams of fast moving currents of air)
What happens when the cool air reaches the ground surface?
It moves as surface winds either back to the Equator or towards the poles
What are trade winds?
Surface winds blowing towards the Equator
Where do trade winds blow?
From the SE in the southern hemisphere and from the NE in the northern hemisphere
What happens to the trade winds at the equator?
They meet/converge in the ITCZ, and are heated by solar radiation. This causes them to rise, condense and form clouds
What are westerlies?
Surface winds blowing towards the poles
Where do westerlies blow?
From the NW in the southern hemisphere and from the SW in the northern hemisphere
What happens 60° North and South of the Equator?
The warmer surface winds meet colder air from the poles. The warmer air is less dense than the cold air so it rises, creating low pressure
What happens to the air?
Some joins the Ferrel cell and moves back towards the Equator, and the rest joins the polar cell and moves towards the poles
What happens at the poles?
The cool air sinks, creating high pressure. The high pressure air is drawn back towards the Equator in surface winds.
