Instability exists when .....
the rising or sinking air continues to rise or sink of its own accord
What can increase the ELR .....
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
The amount of water vapor a parcle of air can hold depends on its .....
Relative Humidity = ..... / ..... x 100%
Vapor Present / Vapor Possible x 100%
Low level jet streams can be hazardous because the produce .....
strong horizontal windshear near the surface
Conditional stability exists when there is ......
1. Saturated air is unstable
2. Dry air is stable
Strong horizontal windsheat can be encountered above a
The vis and turbulence above a subsistance inversion is .....
better visability and less turbulence
What type of wind will reinforce a land breeze .....
Lower humidity on the lee side of a mountain at low level is likely to be caused by a .....
The adabatic process can be defined as .....
when temperature changes without any transfer of heat into our out of a system i.e. compression
A change in ..... will change relative humidity
A wind blowing up sloping terrain during the day could be .....
an anabatic wind
Saturation of a parcle of air occurs when .....
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
Define Subsidence Inversion .....
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
Define a radiation temperature inversion .....
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
Define frontal inversion .....
When a cold front arrives its leading edge slips in under the warmer air creating the inversion
The onset of a light wind beneath a radiation inversion will cause it to become .....
weaker but deeper
Dew point temperature can be defined as .....
the temperature required for the relative humidity to reach 100%
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?
Name the 3 types of temperature inversions ......
1. Radiation Inversion
2. Frontal Inversion
3. Subsidence Inversion
Stability occurs when .....
the rising or sinking air stops rising or sinking of its own accord
The most common method of cloud formation is .....
cooling of air by expansion until saturation occurs