Please enable JavaScript.
Coggle requires JavaScript to display documents.
Weather types (Air masses intro (Most atmospheric processes result from…
Weather types
Air masses intro
Most atmospheric processes result from regulation of imbalances in distribution of heat, moisture and pressure
In the mid lats the direction of the wind is often associated with a particular air mass which in turn can lead to predictable weather conditions
Air mass = a body of air with approximately uniform physical properties (temp, humidity and stability) over horizontal distances of hundreds of kilometres
-
Air mass theory is a convenient and well used way of describing weather types affecting the UK- but the atm is a fluid and its motion is complex --> variability
-
In the mid lats- strong winds around cyclones pull in air from surrounding regions, so that wind direction has a significant impact on weather
-
Tropical maritime
-
-
-
-
-
If wind speed high: mechanical mixing produces deep boundary layer and stratus or stratocumulus clouds
-
Polar maritime
Originates from N. Canada or Greenland as polar continental air but is modified by long sea track across Atlantic
-
-
In winter: most showers initiated over Atlantic before hitting NW coast, east is usually sheltered
-
-
Polar continental
Polar continental air that reaches UK, originates from Scandinavia or Russia
NE winds will bring it, resulting from high pressure system over Scandanavia
Associated w/ cold conditions in winter and warm & dry in summer due to surface temps at the time- cool and showery in east
-
Returning polar maritime
-
In summer: warm, stratus clouds in SW- coastal showers
-
In winter: stratus cloud, showers over high ground- particularly in West
Tropical continental
-
Moist in air mass depends on sea track over Mediterranean- strong heating over land can trigger thunderstorms
-
-
-
Arctic maritime
-
-
Short, warm and moist unstable track from Arctic