Lesson 301 Evolution Of Clouds

Question 1

The nucleation process can be defined as:

Answer 1

The action leading to the formation of the first new specks as a material begins to undergo a change of state at the boundary between two phases.

Question 2

The process of _______ ________ is one by which molecules of water vapour are brought together in sufficient numbers to form ________ water.

Answer 2

Natural condensation

Liquid

Question 3

Relative humidity in the atmosphere rarely exceeds _____%.

Answer 3

101%

Question 4

Nuclei that become impregnated with water before saturation of the air occurs are called:

Answer 4

Hygroscopic nuclei

Question 5

Particles that require a level of supersaturation to form droplets are called:

Answer 5

Non-hygroscopic nuclei

Question 6

Hygroscopic nuclei are composed of _______ _______ substances.

Answer 6

Water soluble

Question 7

Name the 3 types of nuclei and their dimensions.

ALG

Answer 7

Aitken nuclei: radius less than a tenth of a micrometer
Large nuclei: 0.1 - 1 micrometer
Giant nuclei: 1 micrometer or more
* large are the most active

Question 8

At a temperature of less than ______ all water droplets freeze.

Answer 8

-41 C

Question 9

The evolution and type of cloud depends on what four factors?
AAAS

Answer 9

Amount of water vapour available
Abundance of condensation or freezing nuclei
Stability of the air
Amount of lift

Question 10

For each _____ C increase in temperature, the saturation mixing ratio approximately __________.

Answer 10

10 C

Doubles

Question 11

Most clouds form when moist air is subjected to some type of upward (vertical) motion and cools to the saturation point called the Lifted Condensation Level (LCL). The various types of lifting that lend to the formation of clouds are: LCOM

Answer 11

Large scale lift
Convection
Orographic lift
Mechanical turbulence

Question 12

What are the two main processes that initiate convection in the atmosphere?

Answer 12

Day time heating

Cold air advection

Question 13

Convective lift (in contrast to large-scale dynamic lift) is a small scale thermal process, its domain being in the order of ________ km whereas large-scale dynamic lift is ___________ km.

Answer 13

20-30 km

200-300 km

Question 14

With mechanical turbulence cloud formation, there will always be an ___________ at the top of the mixed layer.
The cloud formed will frequently be __________.

Answer 14

Inversion

Stratocumulus

Question 15

During orographic lift, if the air is dry ______________ cloud will form. If air is moist and stable __________ cloud will form. If the air is moist and unstable __________ cloud will form.

Answer 15

Little if any
Stratiform
Convective