Unit 1A - Weather Hazards - Depressions and anticyclones Flashcards
What are depressions?
Areas of low atmospheric pressure which produce cloudy, rainy and windy weather
What happens at a warm front of depression?
Warm air advances into cold air and is forced to rise above denser cold air
What happens at a cold front of depression?
Warm air undercut by advancing cold air and is forced to rise upwards because it has more energy and is lighter
How are high winds that are often associated with depressions created?
Air rushes in from higher pressure areas around depressions, giving high winds
What happens at both fronts when air rises (depression)?
Air cools and creates water droplets (condenses) forming clouds and rain at both fronts
What is the point called where warm air migrating north from Tropics and cold air migrating south from Artic Region meet, where a depression is formed?
Polar Front
What happens at the final stage of the depression?
Cold front catches up with warm front and an occluded front is created
What are anticyclones?
Areas of high atmospheric pressure where air sinks to earth’s surface. Opposite of depression
How are clear skies formed (anticyclones)?
Air warms as it sinks so no condensation and very few clouds
Characteristics of anticyclones?
Low wind speeds, widely spaced isobars and stable conditions
Conditions of anticyclones in summer?
Cool and dry
Conditions of anticyclones in winter?
Warm and calm
