The Earths Energy Budget

Question 1

Radius of the sun?

Answer 1

7x10^8 metres

Question 2

What conversion happens in the sun?

Answer 2

-Mass deficit converted into energy (5H > He)
-5(1,1)H > H(4,2) + n(1,0)

Question 3

Solar radiation spectrum? Peak?

Answer 3

-0.15 micrometres (UV) to 4 micrometres (infra-red)
- 0.5 micrometres

Question 4

What is the solar constant?

Answer 4

-Radiation received at top of atmosphere at mean Earth-Sun distance which is 1366 Watts per metre squared

Question 5

What is solar wind and what does it cause?

Answer 5

Particulate flux and causes the northern lights

Question 6

What does a black body do?

Answer 6

-Absorbs all radiation received and re-radiates it at the maximum rate possible for its radiating temperature
-e.g. the sun

Question 7

What’s plancks law?

Answer 7

The radiation spectrum of a Black Body is determined by its radiating temperature alone.

Question 8

Stefan Boltzmann law?

Answer 8

As temp increases the area under peak of line increases.

Question 9

Wiens displacement law used for?

Answer 9

Determining temperature of distant stars

Question 10

Wiens displacement law for the sun?

Answer 10

T (Temperature) =2898/0.5 T=5800K

Question 11

How to calculate radiation flux?

Answer 11

F= o(stefan boltzmann constant) T(Temperature)^4

Question 12

Black body temperature and radiation relationship?

Answer 12

As black body temperature decreases the radiation it gives off decreases

Question 13

What does radiation received per unit area at the Earth’s surface depend on?

Answer 13

-The seasonal variation of the distance of the earth from the sun? - seasonal variation in day length.
-Latitude - angle of incidence - angle sun’s rays make with earth’s surface
Fact: Two times more energy received at the equator than the poles every year.

Question 14

How does radiation interact with the atmosphere and the earth’s surface on way towards earth?

Answer 14

Scattered by particles
Reflected by clouds, aerosols, atmosphere
Reflected by surface
Absorbed by atmosphere (mainly ozone and water vapour)
Absorbed by surface

Question 15

Figures for incoming solar radiation?

Answer 15

Scattering (particles), reflection (clouds) and absorption (principally O3, WV) - 43 % ISR
Albedo of earth’s surface - 9% ISR
48% ISR - absorbed by Earth’s surface

Question 16

Cloud incoming solar reflection figures?

Answer 16

-Stratocumulus clouds reflect up to 80 %
-Average for all clouds is 55 %

Question 17

Surface albedo solar reflection figures?

Answer 17

-Ranges from 2 % (calm sea) to > 80 % (fresh snow)
-Affected by angle of incidence
- Top 5 albedo reflective surfaces
Fresh snow 70-80%
Ice 20-70%
Sand desert 35-45%
Soil 10-20%
Grass 7-25%

Question 18

Average planetary albedo?

Answer 18

30+_2%

Question 19

How is albedo affected by polar regions?

Answer 19

-Maximum in January, minimum in July, due to larger seasonal cycle of snow and ice cover in NH
-In low latitudes, planetary albedo = 25 % (mainly cloud cover)
In polar regions, planetary albedo = 80 % (snow/ice, high angle of incidence)

Question 20

Figures for more energy being absorbed at non-pole areas of the poles?

Answer 20

-2½ x more energy received at the top of the atmosphere at the equator than the poles over a year
-6 x more energy absorbed at the Earth’s surface at the equator than the poles over a year

Question 21

Fate of radiation absorbed at earths surface: Re-radiation?

Answer 21

-Re-radiation from the Earth’s surface
-Absorption of greenhouse gases (water vapour, co2, ozone) leads to warming of lower atmosphere.
-Re-radiation by greenhouse gases to Earth’s surface & space.
-(net re-radiation from the Earth’s surface accounts for 39 % of absorbed solar radiation)
-

Question 22

How does radiation interact with the atmosphere and the earth’s surface on way away from earth?

Answer 22

Lost as thermal energy
Evapotranspiration
Latent heat
Surface radiation
Emitted by atmosphere
Absorbed by surface after back radiation
Lost through atmospheric window

Question 23

Fate of radiation absorbed at earths surface: Sensible heat?

Answer 23

-Heating of atmosphere by conduction (from Earth’s surface) and convection
-Accounts for 15 % of absorbed solar radiation
-More important in continental areas

Question 24

Fate of radiation absorbed at earths surface: Latent heat?

Answer 24

-Evaporation (from Earth’s surface) followed by condensation in atmosphere
-Accounts for 46 % of absorbed solar radiation
-More important in oceanic areas

Question 25

What can optical depth also be called?

Answer 25

Bulk emission level

Question 26

What is the zonal heat transfer gradient from net radiation?

Answer 26

-Zonal gradient in long-wave emission from Earth’s surface is less than gradient in short-wave absorption.
-Absorption>emission at 40 degrees North and South.
-Emision<absorption poleward of 40 degrees north and south.

Question 27

Advection?

Answer 27

Atmospheric and oceanic circulation?

Question 28

True or False? Equilibrium is achieved through advection of heat from low to high latitudes? Facts?

Answer 28

True.
-Without advection equatorial temperatures would increase by 14 degrees; polar temperatures would decrease by 25 degrees
-Wind-driven surface currents account for 30 % of poleward heat transport (sensible & latent heat transfer to atmosphere at higher latitudes)

Question 29

Climate features of atmospheric circulation?

Answer 29

-Western coastal areas wetter than eastern counterparts
-Continental interiors relatively dry and greater seasonal temperature fluctuations than at margins (‘continentality’)

Question 30

How is the movement of air affected by Coriolis force associated with Earth’s rotation?

Answer 30

-Deflection of movement to right in Northern Hemisphere and left in Southern Hemisphere

Question 31

What is a Hadley circulation at tropical and subtropical regions?

Answer 31

-In the intertropical convergence zone.
-Heating greatest over equator causes ascending air in convergent flow which creates zone of low pressure at surface.
-Air becomes aloft in divergent flow and moves to each pole where it becomes dry air and cools and sinks at 30 degrees north and south (Horse latitudes).
-Then air returns to flow at surface with NE trade in the North and SE trade in the South and they again converge at the intertropical convergence zone.

Question 32

Describe climate of the intertropical convergence zone? (Lower latitude of earth)

Answer 32

Thick cloud, heavy rainfall, little seasonal temperature change.

Question 33

Describe climate of horse latitudes (30 degrees North and South) ?

Answer 33

Light and variable winds, very dry.

Question 34

What’s a polar cell? Features? (Upper latitude of earth)

Answer 34

-Weak polar cell driven by sinking air at poles
- Occurs above 60 degrees (angle)
-Surface flow direction of equator = polar easterlies
-Climates cold and often arid.

Question 35

Describe climate of mid latitude degrees of earth?

Answer 35

-Westerly surface and upper flows (‘mid latitude westerlies’).
- Associated with planetary (Rossby) waves.
-Number, position and amplitude of Rossby waves variable which leads to wandering high and low pressure systems.
-Warm and cold fronts facilitate heat exchange.