Lesson 301 Evolution Of Clouds Flashcards Preview

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Flashcards in Lesson 301 Evolution Of Clouds Deck (15):
1

The nucleation process can be defined as:

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.

2

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

Natural condensation

Liquid

3

Relative humidity in the atmosphere rarely exceeds _____%.

101%

4

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

Hygroscopic nuclei

5

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

Non-hygroscopic nuclei

6

Hygroscopic nuclei are composed of _______ _______ substances.

Water soluble

7

Name the 3 types of nuclei and their dimensions.
ALG

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

8

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

-41 C

9

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

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

10

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

10 C
Doubles

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

Large scale lift
Convection
Orographic lift
Mechanical turbulence

12

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

Day time heating
Cold air advection

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.

20-30 km
200-300 km

14

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

Inversion
Stratocumulus

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.

Little if any
Stratiform
Convective