Met 6 (Atmospheric circulation)

Question 1

Define air mass?

Answer 1

A body or mass in which horizontal gradients or changes in temperature and humidity are relatively slight.

Question 2

What are the 3 atmospheric circulation cells?

Answer 2

• Polar cell
• Mid-latitude / ferrel cell
• Hadley cell

Question 3

What is the ITCZ?

Answer 3

The intertropical convergence zone, a permanent belt of low pressure around the equator.

Question 4

What is the Hadley cell?

Answer 4

The Hadley cell sits between the equator and 30 degrees N/S. Warm air rising near the equator moved pole-ward in the upper troposphere while cooler air around 30 degrees moves equator-ward at lower levels.

Question 5

What is the mid-latitude / ferrel cell?

Answer 5

The mid-latitude cell sits between 30 degrees N/S and 60 degrees N/S. Warm equatorial air then travels away and descends in subtropical regions around 30 degrees.

Question 6

What is the polar cell?

Answer 6

The polar cell sits between 60 degrees N/S and the N/S pole. Polar air goes away from the poles at low levels and equatorial air goes towards the poles at upper levels.

Question 7

What is the jet stream?

Answer 7

Fast flowing narrow air currents typically have meandering shapes.

Question 8

What are the 5 air mass regions?

Answer 8

• Arctic (A)
• Antarctic (AA)
• Polar (P)
• Tropical (T)
• Equatorial (E)

Question 9

What are the 2 air mass routes?

Answer 9

• Maritime (M)

- Continental (C)

Question 10

What are the 5 features of a tropical continental during summer?

Answer 10

• Very warm
• Relatively dry
• Generally unstable
• Weather clear, occasionally thundery showers
• Visibility moderate to poor

Question 11

What are 4 features of a tropical continental during winter?

Answer 11

• Avg. temperature
• Stable
• Usually cloudy
• Visibility moderate to poor

Question 12

What are 5 features of polar continental with a short sea track?

Answer 12

• Very cold
• Very dry
• Stable
• Clear weather
• Visibility moderate - poor

Question 13

What are 5 features of a polar continental with long sea tracks?

Answer 13

• Cold
• Moist in lower layers
• Unstable
• Rain or showers
• Visibility good

Question 14

What are 5 features of tropical maritime?

Answer 14

• Temperature near sea temp.
• Very moist initially
• Stable
• Low cloud and drizzle which reduces as it moves eastward
• Visibility poor with coastal fog on western approaches

Question 15

What are 5 features of a polar maritime during winter?

Answer 15

• Fairly cold
• Moist
• Unstable
• Heavy showers, sometimes hail and thunder
• Visibility good

Question 16

What are 5 features of Arctic maritime?

Answer 16

• Colder than polar maritime
• Fairly moist
• Unstable
• Heavy showers, sometimes show, hail and thunder on coast
• Visibility very good

Question 17

What are 5 features of a returning polar maritime?

Answer 17

• Warmer than polar maritime
• Fairly moist
• Stable at low levels
• Variable cloud, possible showers
• Visibility usually good

Question 18

Define a front

Answer 18

A boundary between two air masses shown on a weather map as a line.