Cloud Formation

Question 1

Basic Cloud formation

Answer 1

1 ) Air rises (contains water vapour & condensation nuclei)

2 ) Air parcel cools to dew point - Saturation

Question 2

Convection

Answer 2

1 ) ELR allows warm air to rise

2 ) Dew point temp reached (called condensation level)

Question 3

Orographic Uplift

Answer 3

1 ) Humid / moist air evaporates

2 ) Wind pushes moist air up mountain

3 ) Expands & cools (hits dew point)

Question 4

Frontal Uplift

Answer 4

1) Cold & warm air meet

2 ) Heavier cold air stays at surface forcing lighter warm air to rise over it

Question 5

Convergence Uplift

Answer 5

1 ) 2 airstreams meet head on - both move up

2 ) Slow widespread ascent

3 ) Occurs in Low Pressure system

Question 6

Turbulence

Answer 6

1 ) Causes friction with surface

2 ) Cloud between condensation & top of turbulent layer -

3 ) Continually forming (rising air expanding- cooling) & dissipating (sinking air compresses- warms)

4 ) Forms mostly over land (land friction)

5 ) Often dissipates at sunset

• Forms Stratocumulus (SC) cld

Question 7

Latitude heating of cold air mass

Answer 7

1 ) Air moves closer to equator over warmer land mass (changing latitudes -> not solar heating)

2 ) Low level air mass heats while higher air remains cold

3 ) Vigorous convection occurs -> air mass becomes unstable

4 ) Occurs night or day (changing latitudes = temp change

5 ) The faster the air mass moves over surface = greater temp difference between top & bottom layers

6 ) Air becomes increasingly unstable -> CU develops
Then TS

Can occur over land or sea -> day or night

Question 8

Wishing the cld how do rain drops form ?

Answer 8

1 ) Tiny droplets form & grow within cld
(not heavy enough to fall yet)

2 ) Strong updrafts keep droplets in cloud -> droplets build

3 ) droplets weight increases faster then surface area
= Heavier -> need strong winds to keep in cld

• Larger droplets don’t reflect light (create dark clouds)