Weather and Climate

Question 1

Where are typhoons typically found?

Answer 1

Tropical regions over large oceans.

Question 2

The 4 conditions of a typhoon:

Answer 2

1) large ocean area with no friction
2) warm water with temperatures over 26.5°C
3) abundant supply of water vapour
4) global wind circulation with air set in motion from east to west

Question 3

What type of pressure system does a typhoon belong to?

Answer 3

Low pressure system.

Question 4

When is typhoon season in Hong Kong?

Answer 4

Summer.

Question 5

Which part of a typhoon has the lowest pressure?

Answer 5

The eye.

Question 6

In which direction does a typhoon rotate when it is in the Southern Hemisphere, and vice versa, when it is in the Northern Hemisphere?

Answer 6

Southern Hemisphere: clockwise

Northern Hemisphere: anti-clockwise

Question 7

What makes a natural event a natural hazard?

Answer 7

Loss of life and property.

Question 8

The key elements of weather and climate:

Answer 8

• precipitation: type and amount
• pressure
• temperature
• relative humidity
• wind: direction and speed
• other information: UV index, AQHI

Question 9

What does the Hong Kong Observatory do?

Answer 9

• provide the public, the government, the airport and the harbour with accurate information about weather conditions
• issue warning signals under extreme weather conditions
• monitor and record the weather conditions
• educate the public on weather related issues

Question 10

Why is it necessary to set up the Hong Kong Observatory?

Answer 10

• to safeguard our life and property

- to minimise disruptions to economic and social activities during inclement weather

Question 11

Action to be taken when the Thunderstorm Warning Signal is issued:

Answer 11

Stay at home or remain in a dry, safe shelter.

Question 12

Action to be taken when the Landslip Warning Signal is issued:

Answer 12

People should avoid walking or driving close to a steep slope.

Question 13

Action to be taken when the Special Announcement on Flooding in the northern New Territories is issued:

Answer 13

• Stay at home or remain in a dry, safe place.

- Stay away from low-lying areas.

Question 14

Action to be taken when the Very Hot Weather Warning is issued:

Answer 14

Avoid exposure under the sun for too long.

Question 15

Action to be taken when the Cold Weather Warning is issued:

Answer 15

Put on more clothes.

Question 16

Actions to be taken when the Red Rainstorm Warning Signal is issued:

Answer 16

Stay at home or remain in a dry, safe shelter.

Question 17

Action to be taken when the Typhoon Signal Number 8 is issued:

Answer 17

Secure all windows and move potted plants indoors.

Question 18

Action to be taken when the Yellow Fire Danger Warning Signal is issued:

Answer 18

Do not set up fire in the wild.

Question 19

Action to be taken when the Strong Monsoon Warning Signal is issued:

Answer 19

Secure loose objects outdoors.

Question 20

A weather chart displays (1) over (2) at (3).

Answer 20

1) various weather conditions
2) a particular area
3) a particular time

Question 21

Temperature on a weather chart:

Answer 21

Shown by number next to the city.

Question 22

Precipitation on a weather chart:

Answer 22

● rain
❜ drizzle
▽ shower
✱ snow

Question 23

Air pressure on a weather chart:

Answer 23

Shown by isobars, which are black lines joining places with the same air pressure on the chart.

Question 24

Wind on a weather chart:

Answer 24

\_ 2.5 m/s
\___ 5 m/s
◣__ 25 m/s
○ calm

Question 25

Use of sunshine recorder:

Answer 25

Measuring duration of sunshine in hours.

Question 26

Use of wind vane:

Answer 26

Measuring wind direction in compass points.

Question 27

Use of dry-bulb and wet-bulb thermometer:

Answer 27

Measuring relative humidity (how much water vapour is in the air) in percentages.

Question 28

How to calculate relative humidity:

Answer 28

(moisture holding capacity-actual amount of moisture)/moisture holding capacity * 100%

Question 29

The (1) the temperature, the larger the moisture holding capacity.

Answer 29

1) lower

Question 30

What does saturated relative humidity mean?

Answer 30

100% humidity -> condensation -> water drops -> rainfall

Question 31

Where are dry-bulb and wet-bulb thermometers usually stored, and why?

Answer 31

In a Stevenson screen to ensure free movement of air.

Question 32

Use of barometer:

Answer 32

Measuring air pressure in hectopascals (hPa)

Question 33

Use of thermometer:

Answer 33

Measuring air temperature in degrees Celsius.

Question 34

Use of anenometer:

Answer 34

Measuring wind speed in m/s.

Question 35

Use of rain gauge:

Answer 35

Measuring precipitation in mm.

Question 36

A rainstorm is a (1). (2) bring (3) in summer. Large amounts of rainfall may (4). To (5), the Hong Kong Observatory will (6).

Answer 36

1) weather condition with strong winds and heavy rains 2) high summer temperatures and moist onshore monsoons 3) heavy rains and sometimes rainstorms 4) disrupt traffic, and cause flooding or landslides 5) reduce losses and damage 6) issue rainstorm warning signals when there is a rainstorm

Question 37

What does amber, red and black rainstorm warning signals signify respectively?

Answer 37

Amber: heavy rain (>30 mm/hr) Red: heavy rain (>50 mm/hr) Black: very heavy rain (>70 mm/hr)

Question 38

A typhoon is a (1). It is a (2). It is usually associated with (3). However, it is (4) and there are (5).

Answer 38

1) strong tropical cyclone 2) low-pressure system developed over tropical waters 3) dense clouds, very strong winds, heavy rain and sometimes thunder and lightning 4) calm 5) no clouds in the eye of the typhoon

Question 39

On average, there are (1) typhoons in Hong Kong each year. When a typhoon hits a place, it will (2). At its worst, typhoons can cause (3). (4) brought by typhoons may sometimes trigger (5) such as (6).

Answer 39

1) five to seven 2) disrupt economic activity, transport and people's daily life 3) injuries, and loss of life and property 4) heavy rain 5) other natural hazards 6) flooding and landslides

Question 40

Preventive measures for typhoons:

Answer 40

1) good monitoring and warning systems 2) typhoon-proof buildings 3) better land use planning 4) educating people to take precautionary measures

Question 41

Features of typhoon-proof buildings:

Answer 41

- tempered glass with shatter-resistant film - compared with two-sided roofs, winds can flow smoothly over four-sided roofs. this prevents roofs from being lifted away by winds from any direction - made of concrete to increase strength - build on stilt to protect the house from flooding

Question 42

How do we better plan land use in precaution of typhoons?

Answer 42

Move settlements away from the shoreline to reduce the effects of storm surges

Question 43

Remedial measures for typhoons:

Answer 43

1) well-trained rescue teams and emergency aids | 2) open temporary shelters to those affected