Meteorology | Air masses and fronts | Oxford

Question 1

Air masses are coded according to a certain characteristic.

Maritime or continental refers to -

Tropical, Arctic, Polar or Equatorial refers to -

Warm and Cold -

Answer 1

Moisture content

Source region or type

Temperature

Question 2

A front is usually only a few miles wide. If the term ZONE is used, then the region of interaction
is much wider up to -

Answer 2

300nm

Question 3

Arctic Maritime Air:

1. Source
2. Type of weather
3. Time of the year

Answer 3

1. Polar ice cap
2. At the source it is dry and stable, but relative humidity increase as it moves over the Norwegian sea becoming very unstable. Large CB and CU with snow storms and blizzards.
3. September - May

Question 4

Polar Maritime Air:

1. Source
2. Type of weather

Answer 4

1. Northwest area of North Atlantic.
2. Cold moist NW airflow. On approaching UK becomes unstable giving CB and CU, heavy showers, sometimes hail and thunderstorms. s. Cu, Cb most likely over NW coasts and inland in summer. Visibility good except in showers. Bumpy flying. At night inland the cloud dissipates, the clearing skies causing a low level inversion with stable air below - ideal conditions for radiation fog.

Question 5

Polar Continental:

1. Source
2. Type of weather

Answer 5

1. : Siberia (winter only)
2. If the airflow is mainly from the E via continental Europe, then very cold, very dry, no cloud, no precipitation. Becomes unstable hence good visibility. If the airflow comes over the Baltic or North Seas the air will become unstable, with large Cu and heavy snow showers on the E coast of Sweden and the UK. Remains very cold. Visibility good except in showers. n summer the air mass virtually disappears. However, with high pressure over Scandinavia in early to mid summer, there will be a NE flow over the North Sea to E UK. The air originates as dry, warm and stable. Over the North Sea it becomes moist and cool. This results in Haar conditions over E coast of N England and Scotland - very low St, drizzle, advection fog, poor visibility.

Question 6

Tropical Continental (cTw).

1. Source
2. Type of weather

Answer 6

1. : N Africa/SE Europe
2. A warm, dry S or SE flow. No cloud or precipitation, warm or very warm. Visibility moderate except in dust haze which can occur

Question 7

Tropical Maritime (mTw).

1. Source
2. Type of weather

Answer 7

1. The Azores anticyclone.
2. A warm, moist SW air flow. As the air moves north, the temperature reduces (but remains warm). Stability and RH increase. Low cloud, St and Sc. Drizzle or light precipitation. Visibility poor. Advection fog over sea area late spring, early summer, over land winter, early spring. In high summer insolation and convection break down the stability resulting in clear skies or possibly a few small Cu

Question 8

With a warm front, the SC and NS occurs what distance away from the front line?

Answer 8

200/300nm from the front line

Question 9

When the front has little or no movement it is known as a -

Answer 9

quasi-stationary front