Earth's energy balance Flashcards Preview

Climate Change > Earth's energy balance > Flashcards

Flashcards in Earth's energy balance Deck (19)
Loading flashcards...
1

What is the temperature of an object dependent on?

Amount of energy it emits and receives

2

How does Earth give out heat?

Radiation (Earth is in a vacuum so can't conduct heat by conduction or convection)

3

Solar radiation is ...

shortwave

4

Terrestrial radiation is...

longwave (infrared)

5

The hotter the object...

The more the spectrum is shifted to short wavelengths

6

What is the average incoming solar flux over all latitudes?

342 Wm^-2

7

What is Earth's global average albedo?

0.3

8

What would the temperature of the Earth be if there was no atmosphere?

-18ºC

9

How much of a warming effect does the natural greenhouse effect have?

Warming of 33ºC

10

What is emissivity?

The ratio of actually emitted to maximum possible radiation emitted

11

What is the average global emissivity?

0.61

12

What is bare Earth temperature with albedo estimated at?

-18ºC

13

How does the Earth stay in radiative equilibrium when emissivity is decreased?

Earth must radiate at higher temperatures
[E=εσT^4]

14

What temperature would earth be without the heat source of the sun?

-269ºC

15

What is terrestrial radiation?

Thermal radiation emitted by earth

16

What does radiative equilibrium mean?

Energy absorbed by earth is equal to energy emitted by earth to space

17

If earth is in equilibrium with incoming solar radiation, E emitted should be equal. This would make the earth 5ºC. What does this calculation not consider?

Greenhouse effect and the albedo of the earth's surface and clouds

18

What is albedo?

Reflectivity of solar radiation by earth and the atmosphere

19

Even when the radiative balance equation is solved fairly accurately for each latitude band of Earth, the temperature distribution is still not right. Why?

Ignores the transport of heat by weather systems and ocean circulation, which reduces the temperature contrast