Chapter 2 - Temperature And Heating

Question 1

What is specific heat capacity?

Answer 1

The energy it takes to heat up a material by 1 Kelvin. J/K

Question 2

What is the specific heat capacity of water at 25degC?

Answer 2

4.2J/K

Question 3

What is the specific heat capacity of earth/rock?

Answer 3

0.8J/K

Question 4

In what season is the sea warmer than land and why?

Answer 4

Winter because the land radiates its heat energy faster than water.

Question 5

In what season is land warmer than the sea and why?

Answer 5

Summer because it takes less energy to heat up the earth than it does the sea.

Question 6

On a clear day how much solar radiation penetrates through the atmosphere and what happens to the rest?

Answer 6

85% the rest (short wave UV) is absorbed by the ozone layer.

Question 7

What kind of radiation does water vapour absorb in the lower atmosphere?

Answer 7

Long wave IR

Question 8

What is the main source of atmospheric heating and why?

Answer 8

Terrestrial radiation.
This produces long wave radiation, after absorbing short wave radiation, which can be absorbed by gases and is mostly absorbed at the surface.

Question 9

What is diurnal variation of surface air temperatures?

Answer 9

The daily variation of surface air temperatures due to the sun.

Question 10

At approximately what time does the minimum surface air temperature occur and why?

Answer 10

06:30, 30 mins after sunrise.

This is due to the outgoing terrestrial radiation being higher than incoming solar radiation from sunrise until 6:30.

Question 11

At approximately what time does the maximum surface air temperature occur and why?

Answer 11

15:00, 3 hrs after noon.

The incoming solar radiation remains higher than the outgoing terrestrial radiation until 15:00.

Question 12

At what altitude does diurnal variation stop having significance?

Answer 12

3000ft

Question 13

How does surface type affect diurnal variation?

Answer 13

The higher the specific heat capacity the lower the diurnal variation.
Eg water at 4.2J/K had a much lower diurnal variation than earth at 0.8J/K

Question 14

How does cloud cover affect diurnal variation?

Answer 14

It insulates and re radiates heat. This means that constant cloud cover during the day will decrease both the min and max surface temperature.

Question 15

How does wind affect diurnal variation?

Answer 15

It reduces both the minimum and maximum temperatures by mixing the surface air with the air above it.

Question 16

What is insolation?

Answer 16

The solar radiation which reaches the earths surface.

Question 17

What is albedo?

Answer 17

The reflectivity of a surface.

The lower the albedo of a surface the more heat is absorbed and thus thermals occur.

Question 18

What is an inversion.

Answer 18

A layer of the atmosphere where lapse rate is reversed.

Question 19

Name 4 different types of inversion.

Answer 19

Surface cooling
Frontal
Subsidence
Turbulence

Question 20

How does a surface inversion occur?

Answer 20

At night the earth cools faster than the air. The cool earth then conducts heat from the air and cools it so that is it colder than the air above it.

Question 21

What factors aid in the formation of an inversion?

Answer 21

Light/no wind
Dry air
Clear skies
Long nights
Air being over land

Question 22

What effects do inversions have on weather?

Answer 22

The warmer part acts as a weather lid, suppressing convection and trapping air below. This traps pollutants and thus leads to poor visibility.

Question 23

How is an inversion cleared?

Answer 23

Air mass is heated from below.