Global atmospheric circulation *

Question 1

Which is the hottest part of the earth?

Answer 1

the equator

Question 2

Fill the gaps:

• intense ____ from the ___ means air rises at the ______, leading to ___ pressure and ________
• when the air reaches the edge of the atmosphere, it can’t go any further so it travels to the _____ and ______
• the air becomes ______ and ______ and falls creating _____ pressure and ___ conditions at around __ degrees north and south of the equator
• air rises again at around __ degrees north and south, and descends again around __ degrees north and south

Answer 2

• intense heat from the sun means air rises at the equator, leading to low pressure and rainfall
• when the air reaches the edge of the atmosphere, it cam’t go any further so it travels to the north and south
• the air becomes colder and denser and falls creating high pressure and dry conditions at around 30 degrees north and south of the equator
• air rises again at around 60 degrees north and south, and descends again around 90 degrees north and south

Question 3

What does global atmospheric circulation cause across the planet?

Answer 3

• winds across the planet
• areas of high rainfall like tropical rainforests
• areas of dry air like deserts

Question 4

Where is the Hadley cell located?

Answer 4

at the/ either side of the equator

Question 5

What happens in the Hadley cell? (8 points)

key words :

rises, low pressure, cools, rises, north/south poles, 30 degrees, sinks, high pressure, sinks, warmer, drier, equator

Answer 5

• air is heated and rises
• (low pressure)
• air cools and creates cumulonimbus clouds
• air rises higher and is separated and starts to move towards north/south poles
• reaches 30 degrees north/south and sinks
• (high pressure, subtropical)
• as air sinks, it becomes warmer and drier (where deserts are found)
• air flows back to equator

Question 6

Where is the ferrel cell located?

Answer 6

higher latitudes between 30 and 60 degrees north/south

Question 7

What happens in the ferrel cell? (6 points)

key words :

surface, poles, south-westerly, north-westerly, moisture, 60 degrees, north/south, cold, poles, lighter, rises, low pressure, unstable

Answer 7

• air on surface is pulled to poles
• forms warm south-westerly winds in northern hemisphere and north-westerly winds in the southern hemisphere
• wind picks up moisture as it travels over the ocean
• at 60 degrees north/south wind meets cold air from poles
• the warmer air is lighter than the cold polar air so it rises as the two masses meet
• this causes low pressure and unstable weather conditions

Question 8

Where is the polar cell located?

Answer 8

at the poles

Question 9

What happens in the polar cell? (5 points)

key words :

cooled, sinks, high pressure, lower latitudes, warmer air, rises, low pressure

Answer 9

• air is cooled and sinks
• forms high pressure (polar high)
• flows towards lower latitudes
• mixes with warmer air and rises
• forms low pressure (polar low)

Question 10

What is the boundary between the warm and cold air called?

Answer 10

the polar front