Revision Part 1

Question 1

What is albedo?

Answer 1

Reflection coefficient

Question 2

Where would radiation inversion most likely to occur?

Answer 2

Deserts - no clouds, no moisture (water retains heat longer)

Question 3

Planetary albedo?

Answer 3

31% (the other 69% is absorbed by the atmosphere, materials on the surface)

Question 4

Radiative power

Answer 4

The hotter the object becomes the higher its radiative power (rate at which it emits radiation)

Question 5

Terrestrial radiation

Answer 5

The radiation emitted by the planet.

Question 6

The heating of the atmosphere is due to

Answer 6

Longwave radiation, infrared (+15C on average)

Question 7

Greenhouse effect definition and which gases are involved?

Answer 7

The absorption of infrared radiation by certain gases and re-radiated.
Water vapour, carbon dioxide, methane, nitrous oxide and ozone.

Question 8

Advection

Answer 8

Horizontal movement of the air (wind), redistributing the energy within it

Question 9

Turbulence

Answer 9

Mechanical movement of air transfer from top and bottom to top of the friction layer. The lapse rate in the boundary layer (friction layer) will eventually adopt the DALR.
At the upper level of the friction layer an inversion can occur.

Question 10

Why is water vapour important?

Answer 10

It regulates air temperature by absorbing thermal radiation from the sun and earth.

Question 11

Humidity capacity of air is determined by

Answer 11

Temperature; the hotter the air the more water vapour it can hold

Question 12

Relative humidity

Answer 12

The ratio of the amount of water vapour in the air compared to how much it can hold at its present temperature (%)

Question 13

Dew point

Answer 13

The temperature to which a sample of air must be cooled for it to become saturated (any further cooling will cause condensation)

Question 14

Mixing ratio

Answer 14

The ratio in g/kg of water vapor to dry air (the hotter it gets the hotter the mixing ratio - exponentially)

Question 15

Relative humidity approximation

Answer 15

RH % = 100 - 5 x (temp - dew point spread)

Question 16

Dry bulb temperature

Answer 16

The ambient or outside air temperature (OAT)

Question 17

Wet bulb temperature

Answer 17

It is the lowest temperature to which the ambient air (flowing around a moistened thermometer bulb) can be cooled by the evaporation of water. The great the humidity around the thermometer, the less room for evaporation.
Needs heat (from the atmosphere) and a place to go.

Question 18

Adiabatic expansion

Answer 18

No energy can pass into or out of the system (idealization - process is so fast , very isolated, or if the system is very large)

Question 19

Lapse rates - fixed values

Answer 19

• the rate at which temperature drops off with altitude.

SALR - 1.8 Deg C per 1000ft (it depends at the rate that latent heat is released internally , once it gets saturated some of it is going to condense to liquid water (releasing heat)

DALR (not completely dry) - 3 Deg C per 1000ft (constant)

Question 20

Absolutely stable

Answer 20

ELR <1.8°C / 1000 ft = absolutely stable

Question 21

Absolutely unstable

Answer 21

ELR > 3°C/1000ft = absolutely unstable

Question 22

Conditionally unstable (stable if dry, unstable if saturated)

Answer 22

ELR is between 1.8 and 3 = conditionally unstable

Question 23

Lapse rates - stable or unstable

Answer 23

Flat line? Fast lapse rate (unstable) fluffy clouds (Cu), fierce clouds (Cb), unstable, showers .
Steep line? Slow lapse rate ( stable) smooth, stratus

Question 24

Good base

Answer 24

Gap between the OAT and the wet bulb temperature divided by DALR - SALR = cloud base