Air Masses Flashcards
Hadley Cell
Equatorial Air rises and sinks at 30NS
Ferrel Cell
Air flows poleward and eastward near surface
Flows to equator and westward at high latitudes
Polar Cell
Air rises and diverges and travels towards poles
Low levels wind travel south
Tropical Maritime
Stable air from warm humid source (Azores/Canary islands)
Becomes more stable as it moves north
Fog/Stratus/Drizzle/poor visibility/low level cloud
Air becomes cold therefore more humid (fog)
Winter: fog/stratus
Summer: sticky humid air
Polar Maritime
Very cold dry source of air from Greenland
Warms over North Atlantic and becomes unstable
Vigorous uplifting/cumulus cloud/showers/snow/TS
Good visibility
Artic Maritime
Very cold dry source of air from far north
Slight warming/unstable as moves south
CU/CB/good visibility
Snow likely
Effects NH in winter
Returning Polar Maritime
Very cold dry source moves south across Atlantic to become similar to tropical maritime air
Moves NE toward Europe and becomes stable - low cloud/stratus/drizzle
Higher level of cloud will be unstable still (CU/CB)
Morning may see BR/DZ over coasts
Tropical continental
Warm dry source from North Africa/Baltics/Turkey
Little cooling and not much moisture added
Stable hot/dry conditions (low humidity)
Localised TS if humidity picks up over seas
High temps/haze
Polar Continental - Winter
Forms over Siberia region
Stable air source
Very cold and dense
Can bring frost and snow if air gathers moisture across North Sea
Polar Continental - Summer
Warming from land can bring warm days not super hot
Stable
Air mass moving south
Warming from below
Decrease in stability
RH decreases
Air mass moving north
Cooling from below
Stability increases
RH increases
Polar ice caps are a source for
Artic Maritime air
All air masses have stability at there source
Source of any moving air mass is an area of high pressure
