C05 - Pressure Systems

Question 1

A Low-Pressure system is also known as?

Answer 1

Cyclone.

Question 2

Low-Pressure systems are characterised by ‘____’ air, it ‘____’ as the surrounding pressure ‘____’ (3)?

Answer 2

• Rising.
• Expands.
• Falls.

Question 3

The expansion of rising air causes the air to cool and condense which produce what?

Answer 3

Clouds.

Question 4

True or False. Low Pressures are always accompanied by cloud and precipitation?

Answer 4

True.

Question 5

True or False. We can expect bad visibility in Low-Pressure areas? Why (2)?

Answer 5

• False.
• We can expect good visibility due to the rising air clearing pollutants and other airborne contaminants from the bottom of the atmosphere.

Question 6

Name two classification of Low-Pressure systems?

Answer 6

• Deep (intense).

- Shallow (weak).

Question 7

A deep depression has a ‘____’ number of isobars with a very ‘____’ central value (2)?

Answer 7

• Great.

- Low.

Question 8

A shallow low has relatively very ‘____’ isobars and a ‘____’ central value (2)?

Answer 8

• Few.

- Higher.

Question 9

The Coriolis Force deflects air to the ‘____’ in the Northern Hemisphere and to the ‘____’ in the Southern Hemisphere (2)?

Answer 9

• Right.

- Left.

Question 10

What is Buy Ballot’s Law?

Answer 10

With your back to the wind in the Northern Hemisphere, the Low-Pressure system is to your left.

Question 11

From 0 ft to 2,000 ft the surface friction counter acts ‘____’?

Answer 11

Coriolis Force.

Question 12

From 2,000 ft to 5,000 ft the airflow is parallel to the ‘____’?

Answer 12

Isobars.

Question 13

At what point does the rising air stop at?

Answer 13

Tropopause.

Question 14

True or False. An area of Low-Pressure at the surface is matched by an area of High-Pressure at Altitude?

Answer 14

True.

Question 15

When do small scale heat lows occur?

Answer 15

During the day over land masses in the summer.

Question 16

As Surface Temperature ‘____’, the air ‘____’ and becomes ‘____’. This causes the air to ‘____’ through the Atmosphere by ‘____’ (5)?

Answer 16

• Increases.
• Warms.
• Less Dense.
• Rise.
• Convection.

Question 17

Vertical Cloud Formations are called ‘____’ and produce ‘____’ (2)?

Answer 17

• Cumuliform Clouds.

- Rain Showers.

Question 18

What are large scale heat lows?

Answer 18

Many systems around which can reduce the pressure over a large area.

Question 19

Name two special regions during the summer where large scale heat lows can form?

Answer 19

• North America.

- Asia.

Question 20

Heat lows generate around the equatorial region to form the ‘____’?

Answer 20

Equatorial Low-Pressure Belt.

Question 21

True or False. Heat lows migrate towards the Tropic of Cancer and Capricorn depending on the time of the year?

Answer 21

True.

Question 22

Heat lows have ‘____’ up currents which rise to the Tropopause?

Answer 22

Strong Thermal.

Question 23

What does the ITCZ stand for?

Answer 23

Inter Tropical Convergence Zone.

Question 24

What type of weather can be found in ITCZ?

Answer 24

Many isolated by severe Tropical Thunderstorms.

Question 25

What is a Trough?

Answer 25

An elongated area of Low-Pressure.

Question 26

Name two types of Troughs?

Answer 26

• Isobaric Trough.

- Trough Line.

Question 27

What is an Isobaric Trough?

Answer 27

A portion which extends from a Low-Pressure into other system.

Question 28

What is a Trough Line?

Answer 28

Identified as a solid black line on Synoptic Charts.

Question 29

What weather can be found on a Trough Line?

Answer 29

Cumulonimbus Clouds with Heavy Showers of Rain/Hail and Strong Wind Gusts.

Question 30

Low Pressure areas are associated with relatively ‘____’ which flow ‘____’ around the area of Low Pressure in the Northern Hemisphere and ‘____’ in the Southern Hemisphere (3)?

Answer 30

• Strong Winds.
• Anti-clockwise.
• Clockwise.

Question 31

You can also expect good ‘____’ (except in showers), significant ‘____’ and ‘____’ (3)?

Answer 31

• Visibility.
• Cloud.
• Precipitation.

Question 32

A High-Pressure system is also known as?

Answer 32

Anticyclone.

Question 33

In High-Pressure areas the air is ‘____’ and flowing ‘____’ at the surface. The sinking air becomes ‘____’ and its Temperature ‘____’ (4)?

Answer 33

• Subsiding (descending).
• Outwards.
• Compressed.
• Rising.

Question 34

Subsiding air is very ‘____’ which means ‘____’ cannot form (2)?

Answer 34

• Dry.

- Clouds.

Question 35

Descending, warming air creates ‘____’?

Answer 35

Subsidence Inversion.

Question 36

Why is Poor Visibility associated with High Pressure systems?

Answer 36

Due to visible pollutants being trapped beneath the inversion.

Question 37

Anticyclones have ‘____’ cloud formation which create ‘____’ Temperatures at night (2)?

Answer 37

• Low.

- Low.

Question 38

In Autumn and Winter around mid-latitudes, ‘____’ can develop in early mornings?

Answer 38

Radiation Fog.

Question 39

High Pressure areas have a ‘____’ gradient force and so ‘____’ winds exist (2)?

Answer 39

• Weaker.

- Lighter.

Question 40

True or False. An area of High-Pressure at the surface is matched by an area of Low-Pressure at Altitude?

Answer 40

True.

Question 41

Coriolis Force causes the airflow to be deflected to the ‘____’ in the Northern Hemisphere. The resultant airflow moves ‘____’ around an Anticyclone (2)?

Answer 41

• Right.

- Clockwise.

Question 42

Due to surface friction, the flow of surface wind parallel to isobars doesn’t establish itself until above ‘____’?

Answer 42

2,000ft.

Question 43

Where can Warm Anticyclones be found?

Answer 43

30° Latitude either side of the Equatorial Low-Pressure Belt.

Question 44

Sub-Tropical Highs are found between which Latitudes?

Answer 44

20° to 40°.

Question 45

Warm Equatorial Air ‘____’ to the ‘____’, which then ‘____’ becoming more ‘____’ and ‘____’ (5)?

Answer 45

• Rises.
• Tropopause.
• Cools.
• Dense.
• Sinks.

Question 46

In the Northern Hemisphere, a belt of Polar Front Depression exists at higher latitudes than the belt of Warm Anticyclones. These Depressions move from which direction?

Answer 46

West to East.

Question 47

During the summer, the Sub-Tropical Highs expend into the Latitude of Polar Front Depressions. Thus, deflecting the Depression in which direction?

Answer 47

Northwards.

Question 48

True or False. With Cold Anticyclones, patterns of Low Pressure and High Pressure extend North and South of the Equator?

Answer 48

True.

Question 49

Can High Pressure develop in both Polar Regions? If so, what is the name of this pressure system?

Answer 49

• Yes.

- Cold Anticyclone.

Question 50

What can be found between the Polar Front Depressions in the mid-latitudes?

Answer 50

Cold Temporary Anticyclones.

Question 51

Cold Temporary Anticyclones are a consequence of the ‘____’ around them?

Answer 51

Low Pressures.

Question 52

What is a Ridge?

Answer 52

Extension of a High Pressure Region.

Question 53

Define the characteristics of a Col in terms of its location?

Answer 53

Found between two High Pressure areas, surrounded by Low Pressure.

Question 54

Describe the Isobars found in a Col?

Answer 54

Widely spaced.

Question 55

What are the seasonal weather phenomenon found in Cols (2)?

Answer 55

• Summer = Thunderstorms.

- Winter = Fog.