Key Stuff

Question 1

Energy Budgets

Answer 1

models that help to analyse heating + cooling of the atmosphere

Question 2

shortwave radiation

Answer 2

• incoming solar radiation (insolation)
• gets emitted from hot body e.g. sun

Question 3

Longwave Radiation

Answer 3

• the radiation released from earth (1) usually during night time (1)
• LW radiation easily absorbed by GHG on way out, = greenhouse effect (trapped heat warms air)

Question 4

radiation cooling

Answer 4

• when the ground cools as a result of outgoing longwave radiation (1)
• mostly @ night (1)
• calm conditions + clead skies (1)

Question 5

how much of incoming SW is reflected

Answer 5

• 29%
• earth surface (6%)
• clouds (18%)
• scattered by atmospheric particles (5%)

Question 6

how much of incoming SW is absorbed

Answer 6

• 23%
• scattered to atmosphere 5%
• absorbed by atmosphere 14%
• absorbed by clouds 4%

Question 7

absorbed by surface

Answer 7

48%

Question 8

what happens to absorbed 48%

Answer 8

• 12% re radiated to space directly through Space Window
• 5% conduction+convection -> sensible heat transfer
• 25% evap -> latent heat transfer
• 6% LW radiation from surface

Question 9

albedo values
- cumulonimbus cloud
- fresh snow
- concrete
- grass
- asphalt
- tarmac

Answer 9

• 92
• 80
• 22
• 25
• 10
• 5-10

Question 10

sensible heat transfer

Answer 10

• caused by the movement of parcels of air (1) into and out of an area usually by convection/conduction taking its heat with it (1)
• i.e. change of temp, but no change of state

Question 11

latent heat transfer

Answer 11

• the heat transferred without a change of temperature (1) following a change of state (1), e.g. gas -> liquid, liquid -> gas

Question 12

albedo

Answer 12

the % of incoming SW radiation (1) that is reflected back into space from a surface (1)

Question 13

conduction

Answer 13

transfer of heat as a result of CONTACT
- from solid surface to atmosphere

Question 14

convection

Answer 14

upward movement of air (1) caused as a result of surface heating (1) resulting in less dense air (1)

Question 15

evap

Answer 15

change in state from liquid to gas (1) as a result of heating (1)

Question 16

condensation

Answer 16

formation fo water droplets (gas to liquid) (1) as a result of a drop in temp to the dew point (1)

Question 17

diurnal budget

Answer 17

24 hour period, encompassing day and night time energy budgets

Question 18

day time energy budget
6 factor model

Answer 18

1. incoming SW solar radiation
2. reflected SW solar radiation
3. absorbed solar radiation
4. re-radiated LW radiation
5. sensible heat transfers
6. latent heat transfers

Question 19

evaluating incoming Sw radiation (day)

Answer 19

• input will vary spatially + temporally
• depending on latitude + seasonality due to tilt of earth

Question 20

evaluating reflected SW radiation (day)

Answer 20

depends on albedo, as amount reflected then changes amount absorbed etc, can change whole budget

Question 21

evaluating surface absorption (day)

Answer 21

• nature of surface
  –dark granite has low albedo + good conductor so easy absorbs radiation, stores deep under surface to re radiate later
  – light limestone has high albedo + bad conductor so doesn’t absorb well, heat in surface layers
• moisture helps conductivity
• Urban areas have higher SA than rural, so more absorption

Question 22

evaluating latent heat transfer (day)

Answer 22

• more water will mean more LHT occurs, e.g. at lakes, rivers, vegetation etc. means that in these rural areas there will be more temp lost than in urban areas

Question 23

evaluating sensible heat transfers (day)

Answer 23

• conduction doesnt tranfer as much heat as convection

Question 24

evaluating LW radiation (day)

Answer 24

• GHG in atmosphere better at absorbing LW, so warms atmosphere.
• clouds also good at absorbing LW, trap it in atmosphere
• creates greenhouse effect

Question 25

night time energy budget (4 factor model)

Answer 25

1. heat absorbed into surface + given out by conduction
2. LW radiation (output)
3. sensible heat transfers
4. latent heat transfers

Question 26

evaluating heat absorbed into surface + given out by conduction (night)

Answer 26

• heat absorbed in day can be re-radiated at night, can offset radiation cooling
• material w high thermal capacity (brick, concrete, stone) can absorb + store lots of heat during day, release slowly @ night as LW

Question 27

evaluating latent heat transfers (night)

Answer 27

• radiation cooling @ surface means cold surfaces cool air above them, to dew point temp.
• any water vapour will condense
• condensation releases latent heat, providing energy to atmosphere, meaning net gain of energy

Question 28

evaluating sensible heat transfers (night)

Answer 28

• with no insolation, less sensible heat losses at night.
• HOWEVER, at tropics sensible heat transfers may still occur without solar radiation
• w/ no SW, convection less important.

Question 29

evaluating LW radiation (night)

Answer 29

• if cloudless, LW will escape easily
• if cloudy, clouds will absorb and re-radiate to surface, trapping it in lower atmosphere, so less energy loss, less radiation cooling

Question 30

why is there a surplus of radiation energy in some parts of the world and a deficit in the others?

Answer 30

1. angle of overhead sun - tilt and curvature of earth
   - sun always overhead the equator, high intensity @eq.
   - @poles, insolation v. dispersed, less intense. travels through more atmosphere on way to poles bcz angle
2. tilt of earth + seasonality
   - higher latitudes, insolation amount received by earth surface varies seasonally + decreases overall
   - @poles, less direct sun, less/no insolation for many months
3. albedo
   - poles, snow, high reflectivity (75-95%), so incoming SW reflected, therefore temp low
   - dark oceans, forests, urban absorb much more

Question 31

cells

Answer 31

hadley (@equator) -> ferrel (middle) -> polar (near poles)