Weather Information Flashcards
1
Q
What is the composition of the atmosphere?
A
- 78% nitrogen, 21% oxygen, 1% trace gases
2
Q
What are the 4 distinct layers of the atmosphere?
A
- troposphere, stratosphere, mesosphere, and thermosphere
3
Q
What is in the troposphere?
A
- contains the majority of weather, and goes up to around 20,000 feet
4
Q
What is atmospheric stability?
A
- the resistance of the atmosphere to vertical movement
5
Q
How can you determine the stability of the atmosphere?
A
- measuring the difference between the actual temperature lapse rate and the adiabatic rate (3C per 1,000 ft)
6
Q
What are the conditions of an unstable atmosphere?
A
- cumuliform clouds, showery precipitation, turbulence, good visibility
7
Q
What are the conditions of a stable atmosphere?
A
- stratiform clouds, continuous precipitation, smooth air, poor visibility in haze
8
Q
How does wind form?
A
- air moving from areas of high pressure to areas of low pressure
9
Q
In the Northern hemisphere, how does air flow around high-pressure areas?
A
- deflected to the right in a clockwise rotation
10
Q
In the Northern hemisphere, how does air flow around low-pressure areas?
A
- deflected toward low pressure area in a counterclockwise rotation
11
Q
What is wind shear?
A
- a sudden change in wind speed and/or direction
12
Q
What is the most severe type of wind shear?
A
- micro burst
13
Q
What are some indications that a microburst might be forming?
A
- intense rain shaft at the surface and a ring of blowing dust
14
Q
How long do microbursts typically last?
A
- 5 to 15 minutes
15
Q
What are isobars?
A
- lines of constant pressure