Pressure Systems

Question 1

What is a depression

Answer 1

Region of relatively low pressure. Lowest pressure at centre

Question 2

What characterises low pressure systems

Answer 2

Rising air that expands and condenses producing clouds. Good visibility as pollutants cleared by rising air.

Question 3

How do Low pressure formations form

Answer 3

Air rises upto tropopause where it spreads outwards=divergence.
Total mass of atmosphere reduces surface pressure falls and low-pressure system created.

Question 4

What is airflow around a low pressure system

Answer 4

In N.hemisphere wind moves anti-clockwise. Below 3000ft due to surface friction wind vectors converge to centre of low

Question 5

What are the types of low pressure

Answer 5

Small scale heat lows.
Large Scale Heat lows
ITCZ

Question 6

What is a small small scale heat low

Answer 6

During day in summer some surface areas heat up more than others. Surface temperature warms air in contact with it and air rises through convection. Forms cloud that are vertical and called cumuliform.

Question 7

What are large scale heat lows

Answer 7

North American/Asian Low.

Large land masses that become very warm in the summer.

Question 8

What is the ITCZ

Answer 8

Heat lows around equatorial regions form Equatorial Low-pressure belt. Depending on time of year belt migrates north of south to tropics of C’s. Area characterised by strong thermal up currents which rise to tropopause and diverge. Completely encircles earth.