Atmospheric Circulation

Question 1

What factor is the energy of the sun?

Answer 1

An external factor

Question 2

What are the 5 components impacted by the suns energy?

Answer 2

• Atmosphere
• Land surface
• Hydrosphere
• Biosphere
• Cryosphere

Question 3

Outline the global climate in 2018

Answer 3

• 4th hottest year on record
• Linked to climate change - atmosphere and surface of ocean regulate climate
• US and Caribbean has 2 major hurricanes
• Extreme air temp in Japan and Australia

Question 4

Outline the structure of the earths atmosphere

Answer 4

• 78% nitrogen
• 21% oxygen
• 0.09% argon
• 0.04% carbon dioxide

Question 5

What are the different layers of the atmosphere?

Answer 5

• Troposphere - where weather occurs
• Stratosphere - protective layer
• Mesosphere
• Thermosphere
• Exosphere

Question 6

What is the difference between weather and climate

Answer 6

• Weather describes the atmosphere conditions at a specific place and time
• Climate describes the average conditions expected at a specific place and time

Question 7

What is global atmospheric circulation?

Answer 7

• Defined as a wind system with annual and seasonal variations

Question 8

What is solar radiation?

Answer 8

• Provides the energy to drive the global atmospheric circulation
• Not evenly distributed over earths surface
• The same amount of incoming solar radiation is spread out over a larger area near the poles due to the earths tilt

Question 9

Why does the wind blow at the surface and in the atmosphere

Answer 9

2 reasons

• Solar radiation
• Earths rotation

Question 10

How does the earths rotation control why the wind blows on the surface and in the atmosphere?

Answer 10

• The Coriolis effect - a force that makes wind swirl clockwise in Southern Hemisphere and anticlockwise in Northern Hemisphere
• This determines the shape of global atmospheric circulation

Question 11

What is the 3 cell circulation model of the atmosphere

Answer 11

1) Hadely cell - tropical
2) Ferrel cell - mid latitude
3) Polar cell
- Involves the convection of hot and cold air
- Surface winds not directly north or south du to earths rotation
- This forces air to move is easterly and westerly direction

Question 12

What is the intertropical convergence zone?

Answer 12

A narrow zone near the equator where northern and southern air masses converge, typically producing low atmospheric pressure - lots of rain

Question 13

Outline global cloud cover

Answer 13

• Rising warm air carries water vapour

- As air cools the water vapour condenses forming clouds

Question 14

What is heat?

Answer 14

• Heat is the amount of energy of all molecular movement inside a body
• It is transferred from high temp to low temp bodies by a variety of different processes

Question 15

What is temperature?

Answer 15

• Temperature of the air is a measure of the internal energy of the air (speed of air)
• This internal energy is associated with random motion of molecules

Question 16

What is absolute zero?

Answer 16

• The temp below which the temp of any substance cannot fall

- Molecules have zero energy

Question 17

How is heat transferred?

Answer 17

It is transferred from high temp to low temp bodies by a variety of different processes

Question 18

What is conduction?

Answer 18

• The transfer of heat by molecular impact without the transfer of matter itself
• How heat travels between objects in direct contact
• Due to temp difference, occurs in solids at low speeds

Question 19

What is convection?

Answer 19

• The transfer of heat by real movement of matter that occurs only in molecules that are free to move from one place to another
• Occurs in gases and liquids
• Due to density difference, it uses intermediate substance at low speed

Question 20

What is radiation?

Answer 20

• The transfer of heat from a body with a temp higher than absolute zero
• Uses electromagnetic waves at fast speed at high temp with shorter wavelengths

Question 21

What is long wave radiation?

Answer 21

• The ground heats up and re-emits energy as long wave radiation in the form of infrared rays
• Apart of terrestrial regime
• Wave length of 4 -100

Question 22

What is short wave radiation?

Answer 22

• The sun emits shortwave radiation as it is very hot and has a lot of energy to give off
• Wavelength less than 4 due to high temp of suns surface
• Apart of solar regime

Question 23

What is global radiation?

Answer 23

• The sum of all short wave radiation received from direct solar radiation and indirect diffuse radiation
• Result of scattering and absorption of radiation in clouds
• Reflects astronomical factors and distribution of clouds
• Shows strong diurnal variation in intensitiy

Question 24

How is radiation distributed?

Answer 24

• Highest radiation is on side of the equator

- Due to solar angle and global cloud cover

Question 25

What is the albedo effect?

Answer 25

Light surface reflects more heat than dark surfaces

Question 26

What is surface albedo?

Answer 26

The fraction of shortwave radiation received that is reflected by a surface

Question 27

What is planetary albedo?

Answer 27

The reflection of shortwave radiation by the whole planet with 3 elements:

1) radiation reflected by land or sea surface
2) radiation reflected by clouds
3) radiation back scattered by the atmosphere

Question 28

What is net radiation?

Answer 28

• The difference between the total incoming and total ongoing radiation
• Averaged over the year, there is a net energy surplus at the equator and deficit at the poles
• This equator vs pole imbalance is a fundamental driver of atmospheric and oceanic circulation