Atmospheric Circulation

Question 1

Barometer

Answer 1

Is used to measure air pressure

Question 2

Wind

Answer 2

Is the horizontal motion across the Earths surface

• It is created by gradients in air pressure/density
• The greater the pressure gradient/difference the stronger the wind is

Question 3

Forces that determine winds:

Answer 3

• Pressure gradient force
• Coriolis Effect
• Frictional Force

Question 4

Pressure Gradient Force

Answer 4

• Is responsible for generating wind to blow from high pressure to low pressure perpendicular to the isobars
• Fluids like air/water move from areas of high pressure to low pressure

Question 5

Wind blows which was to the isobars?

Answer 5

They blow perpendicular to the isobars from a high pressure zone to low pressure zone

Question 6

When considering PGF on its own, the angle is…

Answer 6

Perpendicular

Question 7

How are convection loops created?

Answer 7

They are created by unequal heating a cooling of the surface

Question 8

Pressure gradient controls…

Answer 8

Horizontal air movement

Question 9

Air temperature controls…

Answer 9

Vertical air movement

Question 10

Coriolis Effect

Answer 10

Is an apparent force caused by the Earth’s rotation

Question 11

Coriolis force is always ____ to the wind

Answer 11

Perpendicular

Question 12

Coriolis Force =

Answer 12

PGF, then the wind blows parallel to the isobars with low pressure to the left if you’re in the Northern Hemisphere

Question 13

Geostrophic Winds

Answer 13

Are upper atmospheric winds with no friction
- Upper level winds run parallel to the isobars, with low pressure to the left when you’re unfacing the wind in the northern hemisphere

Question 14

Friction Force

Answer 14

• Friction from the surface slows wind speed and combines with other forces to influence wind direction, basically friction slows down wind

Question 15

The effect of friction extends to about…

Answer 15

500m above the surface

Question 16

The winds from a northern hemisphere cyclone rotate

Answer 16

counter-clockwise

Question 17

The winds from a low pressure system in the Southern Hemisphere rotate:

Answer 17

clockwise

Question 18

Why do cyclones in the northern and southern hemisphere spine in opposite directions?

Answer 18

Because of the Coriolis effect

Question 19

Will land or land near the water be cooler? Why?

Answer 19

Land near the water will be cooler as land warms up quickly during the day and cools down quickly at night

Question 20

Why will the water stay warm at night?

Answer 20

Because water has the capacity to store heat for a longer period of time

Question 21

It is always low pressure…

Answer 21

Along the surface of the equator as it is near the tropics (its always warm near the equator)

Question 22

What kind of cells does the subtropics have?

Answer 22

High pressure cells

Question 23

Why do the poles have high pressure?

Answer 23

Cause it is so cold at the poles, the air falls

Question 24

Atmospheric circulation between the equator and the sub tropics is called:

Answer 24

Hadley cells

Question 25

Winds coming from the north east are called:

Answer 25

Northeast trade winds

Question 26

Winds coming from the south east are called:

Answer 26

South east trade winds

Question 27

Where does the low pressure belt exist?

Answer 27

The ITCZ

Question 28

The subtropics has what type of pressure?

Answer 28

High pressure

Question 29

Winds blow from...

Answer 29

High pressure to low pressure

Question 30

What is a front?

Answer 30

Two air masses with contrasting temperatures - At mid latitude we receive air from the poles (cold) and air coming from the subtropics (warm) this causes cold air to meet with the warm air and is called a front

Question 31

What do high poles generate?

Answer 31

Easterlies

Question 32

Hadley cells generate...

Answer 32

Northeast and Southeast trades

Question 33

Westerlies

Answer 33

Are the dominant surface winds from the subtropics to high latitudes

Question 34

What is associated with the equator?

Answer 34

The intertropical convergence zone

Question 35

Equatorial Low Pressure Trough

Answer 35

- High insolation warms equatorial air, the air rises and produces a zone of low pressure - Air from both hemisphere flow toward the surface low and moves aloft as part of the Hadley cell - This area of convergence is known as the ITCZ

Question 36

Subtropical High Pressure Belts

Answer 36

- Air descending part of Hadley cell is heated by compression and becomes drier - The surface air diverging form the subtropical highs generate earth's principle surface (mid latitude westerlies, tropical trade winds) - Like the ITCZ, the high pressure cells "follow" the sun migrating 5-10 degrees in latitude

Question 37

Polar High Pressure Cells

Answer 37

- Weak high pressure cells with little energy | - Winds move away from the polar region in an anti-cyclonic direction producing the polar easterlies

Question 38

The ITCZ changes...

Answer 38

Above or below the equator depending on the time of year

Question 39

Upper Atmospheric Circulation:

Answer 39

- Pressure decreases less rapidly with height in warmer air - Differential heated causes air to flow poleward, therefore the pressure gradient is greater at altitude and winds tend to be stronger

Question 40

Jet streams

Answer 40

Are narrow high speed upper level air flows - It is a river of fast moving air in the upper atmosphere - It steers storms and moves weather patterns across the globe

Question 41

Jet streams are driven by...

Answer 41

- The temperature differential between the Arctic and mid latitudes. - If the temperature differential is large, then the jet stream speeds up - If the temperature differential reduces cause of a warming Arctic, then the jet stream weakens

Question 42

When the jet stream goes up (ridge) we see...

Answer 42

Warm and dry weather

Question 43

When the jet stream goes down (trough) we see...

Answer 43

Cooler and wetter weather

Question 44

Rossby Waves

Answer 44

Are the undulations of the upper level westerly winds | - As viewed from space, they have half the rotational speed of Earth