The Climate of Earth and Other Planets

Question 1

How do you calculate the temperature of planets and moons?

Answer 1

A box model.

The model balances incoming solar energy against outgoing infrared energy.

Question 2

What are the shortcomings of the box model?

Answer 2

The box model only works for mars and the moon.
It fails to predict the temperature of Venus and earth.
This is because the box model does not account for atmosphere.

Question 3

How far up in infrared radiation emitted?

Answer 3

Up to 5.5km up

Question 4

Oceans -

Where is most of the heat absorbed?

Answer 4

20m down

Question 5

Oceans -

What is the length of the mixed layer in the ocean?

Answer 5

From 20 to 100km

Question 6

What is heal flow?

Answer 6

the rate of energy transfer between an object

Question 7

What is the unit of measurement for heal flow?

Answer 7

jewels per second/ kilo watts

often talked about through unit per area

Question 8

What factors affect temperature?

Answer 8

1. Distance from sun
2. Albedo
3. Atmosphere

Question 9

Which planet is an example of how albedo impacts temperature?

Answer 9

Venus - close to sun yet reflects 90% of infa-red energy

Question 10

What is solar irradiance?

Answer 10

The power per unit area received from the sun in the form of electromagnetic radiation.

Question 11

What is the solar irradiance when the sun shines directly on the earth?

Answer 11

Solar irradiance = 1361 W m-2

Question 12

What factor is the solar irradiance divided by?

Answer 12

4

Question 13

Why is solar irradiance divided by 4?

Answer 13

• Half of the earth is in shadow

- most of the day surface is obliquely lit

Question 14

What is the actual solar irradiance?

Answer 14

340 W m-2

Question 15

What percentage of incoming energy does the earth reflect?

Answer 15

30%

Question 16

How do you work out planetary temperature?

Answer 16

1. Caluculate solar heating using distance from the sun
2. Multiply by (1-albedo) to get flux into planet’s climate system
3. Find the temperature that gives a matching flux out using
   - Const. x (t+273C) 4

Question 17

What is the troposphere?

4 points

Answer 17

• lowest layer of earth’s atmosphere (0-18km)
• where weather takes place
• 99% of water vapour stored here

Question 18

What is the stratosphere?

Answer 18

• layer above the troposphere
• stratified in temperature,
• warmer layers higher and cooler layers closer to the Earth
• increase of temperature with altitude is a result of the absorption of the Sun’s ultraviolet radiation by the ozone layer

Question 19

As you go higher into the troposphere, what is the temperature gradient?

Answer 19

• 6 to 10 degrees C per km of altitude

Question 20

Why can thermal radiation increase quickly as temperature increases?

Answer 20

• is to the power of 4 in equation

- if temperature increases by 1%, radiation increases by 4%

Question 21

What kind of heat flow happens in the ocean?

Answer 21

Vertical flows of heat

Question 22

Why does vertical exchanges happen?

Answer 22

• mixing in the top 100m is wind driven

Question 23

Where does ocean mixing happen?

Answer 23

in the top 100m