depressions and anticyclones

Question 1

Describe the formation of a depression.

Answer 1

~The tropical maritime interacts with polar maritime air mass, causing a polar front.
~warm air rises above the dense cooler air and gets twisted by the jet stream & coriolis effect.
~These warm & cold fronts now rotate anti-clockwise
~Cold front is faster so catches up with the warm front, causing and occluded front. Air is lifted entirely from the ground.

Question 2

Describe the characteristics of an anticyclone.

Answer 2

> high pressure > no clouds, clear sky
humidity reduced > dry, stable conditions
low wind speeds > one air mass, no fronts
block fronts > 3,000km wide typically
air moves down from troposphere
increased pressure heats up air
dry adiabatic lapse rate

Question 3

State the differences between an anticyclone in summer and winter.

Answer 3

winter: - temperatures below freezing or 5c
- cold nights; no clouds holding warmth in
- radiation fog in morning or low level clouds
- atmospheric pollution; no wind to disperse

summer: - temperatures over 20c at midday
- sunny, no rain
- rapid radiation causes temperature inversion
- coasts can receive fog
- thunderstorms as warm air is rapidly rising