Air Masses + Pressure Systems Flashcards
What are the two classification of Air masses?
Polar
Tropical
What are sub categories of air masses?
Continental
Maritime
What Air mass produces
High temp/DP/Humidity
Warm moist and hazy with broken cloud. Advection fog over coast and sea (summer)
Warm and Moist with low cloud or fog + drizzle (winter)
Warm and moist with low cloud or fog and drizzle?
Tropical maritime
What Air mass produces
High temp, low DP/Humidity
Warm + dry overland with little cloud but often hazy due to dust particles from air mass (summer)
Tropical continental
What Air mass produces
Low temp, High DP/ Humidity
Cool with showers, thunderstorms near the coast and clear inland. Good visibility except in precipitation (summer)
Surface cooling over the land and becomes stable. Possible layer cloud/fog over night (winter)
Polar maritime
What Air mass causes
Low temp/DP/Humidity
Rain or snow showers but often cold and clear inland (winter)
Polar continental
What are two other Air masses effecting Europe?
Equatorial- moist and unstable
Continental Arctic - very cold, dry and stable.
An area of high pressure is known as
An anticyclone
An area of low pressure is known as a
Depression/cyclone
How is an anticyclone formed?
Rising surface pressure causes divergence. Draws cold air down from above.
List the different types of depressions
- frontal
- Instability
- secondary
- orographic
- thermal
- trough
How is a depression formed?
Air rises and cools Adiabatically. If it is sufficiently moist will give thick cloud and precipitation
What is a ridge?
An area of high pressure which elongates. Shown by a zig zag line on a chart
What is a trough?
An elongated area of low pressure.
Where does polar continental air mass come from?
Siberia
