Anticyclones Flashcards
Anticyclones are an area of…
high pressure
In an anticyclone, air…
sinks slowly from tall heights in the centre
As air sinks in an anticyclone, it…
swirls in a clockwise direction and spreads out at the surface
Sinking air in an anticyclone becomes…
compressed and warms up as it nears the ground, meaning the air can hold more water vapour without condensation taking place, meaning clouds do not form and it is less likely to rain
Anticyclones move…
slowly, meaning weather remains the same for several days
The isobars showing an anticyclone are…
far apart
List three characteristics of anticyclones.
- Dry
- Little or no cloud
- Calm or gentle wind
Summer anticyclones bring…
bright sunshine and cloudless skies
Day temperatures in a summer anticyclone are…
high because of cloudless skies
Night temperatures in a summer anticyclone can be…
cool, as the Earth radiates its heat out into the atmosphere when there are no clouds
Day temperatures in winter are low because…
days are short and the sun is not powerful
Winter anticyclones cause cloudless skies at night which…
allows the temperature to fall below 0 degrees C and frost forms
Winter anticyclones often bring…
fog or mist
Fog or mist forms at night in a winter anticyclone when…
rapid cooling occurs and heat is lost by radiation due to the lack of cloud cover.
Water vapour in the cold layer of air near the ground condenses and the water droplets are suspended in the air as mist or fog.
In winter, the low angle of the sun means that…
the sun’s rays cannot disperse the fog or mist and it may persist all day
