Met - Water in the Atmosphere

Question 1

Instability exists when …..

Answer 1

the rising or sinking air continues to rise or sink of its own accord

Question 2

What can increase the ELR …..

Answer 2

Anything that increases the difference between the top and bottom of the atmosphere i.e.

1. Warming of the lower levels
2. Cooling of the upper levels

Question 2

The amount of water vapor a parcle of air can hold depends on its …..

Answer 2

temperature

Question 3

Relative Humidity = ….. / ….. x 100%

Answer 3

Vapor Present / Vapor Possible x 100%

Question 3

Low level jet streams can be hazardous because the produce …..

Answer 3

strong horizontal windshear near the surface

Question 4

Conditional stability exists when there is ……

Answer 4

1. Saturated air is unstable
2. Dry air is stable

Question 5

Strong horizontal windsheat can be encountered above a

Answer 5

surface inversion

Question 5

The vis and turbulence above a subsistance inversion is …..

Answer 5

better visability and less turbulence

Question 6

What type of wind will reinforce a land breeze …..

Answer 6

Katabatic wind

Question 6

Lower humidity on the lee side of a mountain at low level is likely to be caused by a …..

Answer 6

Fohn Wind

Question 8

DALR =

Answer 8

3⁰/1000ft

Question 9

The adabatic process can be defined as …..

Answer 9

when temperature changes without any transfer of heat into our out of a system i.e. compression

Question 10

ELR=

Answer 10

2⁰/1000ft

Question 11

A change in ….. will change relative humidity

Answer 11

temperature

Question 11

A wind blowing up sloping terrain during the day could be …..

Answer 11

an anabatic wind

Question 13

SALR =

Answer 13

1.5⁰/1000ft

Question 14

Saturation of a parcle of air occurs when …..

Answer 14

1. Water vapor is at a constant temperature and more water vapor is added until saturation occurs to that parcle of air
2. The parcle of airs temperature is reduced until it can no longer hold any more vapor

Question 16

Define Subsidence Inversion …..

Answer 16

1. As air moves down in a high it warms adabatically
2. Near the surface it moves out horizontally
3. The horizontal movement has no adabatic heating associated
4. This means that the air above is warmer becuase of the compression
5. This is associated with every high pressure system and usually occurs between 4000ft and 8000ft

Question 18

Define a radiation temperature inversion …..

Answer 18

1. Air cools at night when in contact with the cold ground
2. This cold air becomes a layer
3. Gentle breezes deepen this layer
4. This will not occur on windy or cloudy nights

* Thing Radiation Inversion think Low Level Jet Stream

Question 19

Define frontal inversion …..

Answer 19

When a cold front arrives its leading edge slips in under the warmer air creating the inversion

Question 20

The onset of a light wind beneath a radiation inversion will cause it to become …..

Answer 20

weaker but deeper

Question 21

Dew point temperature can be defined as …..

Answer 21

the temperature required for the relative humidity to reach 100%

Question 22

CU cloud with a base of 3000ft AGL is observed over an aerodrome. The eleveation of the aerodrome is 2000ft AMSL and the temp is 18⁰C. What height can freezing be expected in the cloud?

Answer 22

11,000ft

Question 24

Name the 3 types of temperature inversions ……

Answer 24

1. Radiation Inversion
2. Frontal Inversion
3. Subsidence Inversion

Question 25

Stability occurs when …..

Answer 25

the rising or sinking air stops rising or sinking of its own accord

Question 26

The most common method of cloud formation is …..

Answer 26

cooling of air by expansion until saturation occurs