Evolution of Clouds

Question 1

Define Nucleation process

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 to phases.

Question 2

Describe the process of Natural Condensation

Answer 2

The process in which molecules of water vapor are brought together in sufficient numbers to form liquid water. It requires Supersaturations

Question 3

What are Hygroscopic nuclei? and what are they composed of?

Answer 3

Nuclei that become impregnated with water before saturation of the air occurs. The are composed of water soluble substances.

Question 4

What size are large nuclei?

Answer 4

0.1 to 1 micrometer

Question 5

How long does it take a hygroscopic nuclei 1 micrometer in diameter to grow to a 1mm drop of rain?

Answer 5

3 hours

Question 6

The process of cooling a water droplet’s temperature beyond its nominal freezing point is called:

Answer 6

Supercooling

Question 7

At what temperature do all droplets freeze?

Answer 7

-41

Question 8

Freezing occurs at much warmer temperatures than -41 because of:

Answer 8

Particles that act as freezing nuclei

Question 9

The universal theory about freezing nuclei states that:

Answer 9

Certain condensation nuclei are a mixture consisting of hygroscopic substances and solid substances. thus, condensation takes place on the hygroscopic part and freezing takes place on the solid substance.

Question 10

As the temperature lowers, the amount of freezing nuclei increases or decreases?

Answer 10

increases

Question 11

List the 4 factors that control the evolution of clouds

Answer 11

1. Water vapor
2. Condensation and ice nuclei
3. Stability
4. Lift

Question 12

For every 10 degrees the temperature increases, the amount of water vapor it can hold:

Answer 12

doubles

Question 13

At temperatures below the freezing point, the ratio of the number of ice crystals to supercooled droplets ________ as the temperature _________

Answer 13

increases

decreases

Question 14

The 4 types of vertical lift that assist in the formation of clouds are:

Answer 14

Large scale lift
Convection
Orographic lift
Mechanical turbulence

Question 15

The two main processes that initiate convection in the atmosphere are:

Answer 15

Day time heating

Cold Air advection

Question 16

What are the 3 key points of daytime heating:

Answer 16

Unequal heating of the earths surface
Surrounding air is colder than the parcel
small scale process

Question 17

What are the 2 key points about CAA

Answer 17

Warmer surface below

Day or night

Question 18

Intensity and altitude of mechanical turbulence depends on

Answer 18

roughness of the surface
Strength of the wind
inStability of the air

Question 19

The cloud formed by mechanical turbulence will frequently be:

Answer 19

Stratocumulus unless the layer is very moist, then stratus.

Question 20

there will always be an __________ at the top of the mixed layer

Answer 20

Inversion

Question 21

With orographic lift, the extent of the cloud depends on ________ and the type of cloud depends on ________

Answer 21

The moisture of the air

The stability of the air

Question 22

The cloud associated with lows and troughs and the fair weather associated with ridges and highs are due to:

Answer 22

Slow air mass decent or ascent caused by convergence or divergence.

Question 23

The cloud produced by large scale vertical motion is generally:

Answer 23

Layered cloud. Cirrus, Altostratus or nimbostratus.

Question 24

The process of break-up of an ice crystal into a large number of fragments is referred to as the:

Answer 24

fragmentation.