C5.4 Typhoon

Weather and Climate
Introduction

C5 Living with Natural Hazards

Climatic graph (F.2 Book 4 P.77)

Climatic graph P.77

​annual: yearly

Climatic characteristics

​Rainfall characteristics:
1. (high/ moderate/ low) annual rainfall
2. (evenly/ unevenly) distributed
3. (high/ moderate/ low) summer/ winter rain?

​Temperature characteristics:
1. (small/ large) annual range of temperature
2. (high/ moderate/ low) annual mean temperature
3. (high/ moderate/ low) mean (season) temperature

Hong Kong Observatory

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​https://www.hko.gov.hk/en/index.html

Complete the climatic graph on P.49 and describe the climate in Guangzhou.

Open Ended

P.49: Describe the temperature pattern in Guangzhou.

Open Ended

P.49 Describe the rainfall pattern in Guangzhou.

​P.50 Fill in the blanks

​P.50 Fill in the blanks

​Describe the seasons in HK.

​P.50

Word Cloud

Describe SPRING in Hong Kong.

Word Cloud

Describe SUMMER in Hong Kong.

Word Cloud

Describe AUTUMN in Hong Kong.

Word Cloud

Describe WINTER in Hong Kong.

​P.50

Why is the climate in winter and summer so different?

​P.51

​Remember F.2 geography?

​Rainfall factor - monsoon system

Why are the winds changing directions?
They are formed by the differences in the heating of land and sea.

Change in temperature -> change in air pressure

​Rainfall factor - monsoon system

​Understand the difference between land and sea
-> different heating capacity

​Rainfall factor - monsoon system

​Land: lower heating capacity
Sea: higher heating capacity

Land takes shorter to heat up or cool down
Sea takes longer to heat up or cool down

Multiple Choice

In summer,

the temperature of ______ increases quicker.

• land

• sea

Multiple Choice

In winter,

the temperature of ______ decreases slower.

• land

• sea

land

sea

​SUMMER

​warmer

cooler

​WINTER

land

sea

​warmer

cooler

land

Labelling

Label the air pressure in China in summer.

(L: low; H: high)

Hint: think about the temperature

Drag labels to their correct position on the image

H

L

Labelling

Label the air pressure in China in winter.

(L: low; H: high)

Hint: think about the temperature

Drag labels to their correct position on the image

H

L

Remember:

1) high temperature → low pressure (opposite!)

2) hot air rises; cold air sinks (due to expansion & contraction)

3) Air moves from high pressure to low pressure!
(Just like you! stressful → relax)

*Remember summer monsoon and
winter monsoon is the exact opposite!

​SUMMER

​WINTER

​L

H

H

​L

​hot air rises

​hot air rises

​cold air sinks

​cold air sinks

​Wind direction is always from HIGH to LOW pressure!
~When you're under pressure, you want to escape/ do something relaxing!

Draw

Draw the arrow showing the wind direction in the figures.

​SUMMER

​WINTER

​L

H

H

​L

​hot air rises

​hot air rises

​cold air sinks

​cold air sinks

​hot air rises up
-> low pressure

​cold air sinks
-> high pressure

​-> high
pressure

-> low
pressure

​Complete P.51 now.

​P.51

What are the common extreme weather conditions in summer? p.52​

​A. Common extreme weather conditions

What are they called? When do they occur?​

Multiple Choice

P.52: What are they called?

• raining warning

• rainfall warning

• rainstorm warning

• rain warning

Multiple Choice

P.52: In which season do rainstorms usually occur?

• spring

• summer

• autumn

• winter

Multiple Choice

P.52: Why do rainstorms occur in summer?

It is because temperature is _______. So air tends to expand and rise.

Besides, monsoon winds blow ________ bring heavy rains.

• low, onshore

• low, offshore

• high, onshore

• high, offshore

​p.52

​B. Common extreme weather condition

​

What does it call?

​Structure of typhoon

​P.53

Multiple Choice

P.53 Checkpoint 12 Q1

• A

• B

• C

• D

Multiple Choice

P.53 Checkpoint 12 Q2

• A

• B

• C

• D

Multiple Choice

P.53 Checkpoint 12 Q3

• A

• B

• C

• D

​How low is the pressure at the centre of typhoon?
p.54

P.54

4 elements represented by the symbols:
(1) air pressure - isobars
(2) air temperature - number
(3) wind (direction and speed)
(4) precipitation

​(1)

​(2)

​(3)

​(4)

Weather symbols

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Multiple Choice

P.54 Describe the weather in Hong Kong.

The air temperature of HK is _______.

• 24 ºF

• 29 ºC

• 24 ºC

• 29 ºF

Multiple Choice

P.54 Describe the weather in Hong Kong.

Which type of precipitation is found?

• drizzle

• shower

• rain

• snow

Multiple Choice

P.54 Describe the weather in Hong Kong.

In which direction does the wind blow from?

• northeast

• northwest

• southeast

• southwest

Multiple Choice

P.54 Describe the weather in Hong Kong.

What is the wind speed?

• 5 m/s

• 7.5 m/s

• 7.5 km/h

• 5 km/h

Multiple Choice

P.54 Describe the weather in Hong Kong.

The air pressure of Hong Kong is ________hPa.

• 1004

• 1005

• 1006

• 992

Multiple Choice

P.54 Relationship between air pressure and wind speed

Compare the air pressure and wind speed at X and Y.

Which location has a larger change in air pressure?

(Hint: note the spacing of isobars)

• X

• Y

Multiple Choice

P.54 Relationship between air pressure and wind speed

Compare the air pressure and wind speed at X and Y.

Place Y has a larger change in air pressure and a _________ wind speed.

• lower

• higher

Multiple Choice

Refer to Figure 8a. The air pressure at the centre of typhoon is _________.

• higher than 988 hPa.

• lower than 988 hPa.

• equal to 988 hPa.

​How low is the pressure at the centre of typhoon?

The pressure at the centre is lower than 988 hPa.

​Let's finish Booklet P.20 together.

HW: P.21-23

​P.55

​P.55

Multiple Choice

Describe the change in air temperature when typhoon approached Hong Kong.

• increase

• decrease

Multiple Choice

Describe the change in air pressure when typhoon approached Hong Kong.

• increase

• decrease

Multiple Choice

Describe the change in wind speed when typhoon approached Hong Kong.

• increase

• decrease

Multiple Choice

Describe the change in precipitation when typhoon approached Hong Kong.

• increase

• decrease

​P.57

Formation of typhoon

1. Where do typhoons usually develop?

2. How do typhoons form?

​WS p.24

​BK P.56
WS P.24

​What are the favourable conditions for a typhoon to form?

​BK P.57
WS P.24

​BK P.57
WS P.24

​BK P.57
WS P.24

Multiple Choice

Q1. Tropical cyclones are __________ systems developed over tropical oceans.

• low pressure

• high pressure

Multiple Choice

Q2. At which of the following sea surface temperatures will tropical cyclones most likely form?

• A. 22.5°C

• B. 24.5°C

• C. 26.5°C

• D. 28.5°C

Watch the video.

​Observe the changes in the strength of
Typhoon Yolanda.


- What happened to Typhoon Yolanda after passing by the Philippines?

Multiple Choice

What happened to Typhoon Yolanda after it passed by the Philippines?

• became stronger

• became weaker

• no change in wind speed

Open Ended

Suggest why it became weaker after it passed by the Philippines.

​WS P.24

WS P.24

​WS P.24

​BK P.57

Multiple Choice

Textbook p.57 Q2

• A

• B

• C

• D

Multiple Choice

Textbook p.57 Q3

• A

• B

• C

• D

​BK P.57

Multiple Choice

A low pressure centre is difficult to develop into a tropical cyclone when...

• A. air moves into the low pressure centre continuously

• B. sea surface temperature decreases

• C. convection of air is strong

• D. hot and wet air rises and condenses to form clouds

Multiple Choice

The continuous movement of air into the low pressure centre causes an increase in __________.

• A. temperature

• B. air pressure

• C. wind speed

What are the negative impacts brought by typhoons?

Interactive Map of Storm Damage by Mangkhut｜Hong Kong Observatory(HKO)｜Community

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Open Ended

BK P.56 What are the negative impacts of typhoons? [Write at least 3]

​WS P.25
BK P.58

BK P.58

​BK P.58

​BK P.58

How can people prepare for and respond to typhoons?

Two types of measures (BK p.54)

• Preventive measures

• Remedial measures​

Multiple Choice

Which type of measures, preventive or remedial, are carried out before the hazard to reduce the losses?

• Preventive

• Remedial

​BK P.59 & WS P.26 Q1

​The Hong Kong Observatory issues typhoon warning signals.

Open Ended

What other warning signals which may also be hoisted during typhoon?

[List out some examples]

​BK P.59 & WS P.26 Q1

​BK P.59 & WS P.26 Q2

Open Ended

Suggest a precautionary action that you should take during a typhoon.

​BK P.59 & WS P.26 Q2

​BK P.59 & WS P.27 Q3

​BK P.59 & WS P.27 Q4

​BK P.59 & WS P.27

​BK P.59 & WS P.27

​https://maps.app.goo.gl/T8mrEEpj6QowUowj6

Multiple Choice

1. In Hong Kong, the monitoring and forecast of tropical cyclones are carried out by the ______.

• A. Drainage Services Department

• B. Hong Kong Observatory

• C. Agriculture, Fisheries and Conservation Department

• D. Environmental Protection Department

Multiple Choice

2. Which of the following is NOT a preventive measure of tropical cyclones?

• A. Raise public awareness by education

• B. Organise inter-departmental drills

• C. Send rescue teams to affected areas

• D. Issue early warnings

Multiple Choice

3. Provision of temporary shelters is a remedial measure of tropical cyclones.

• A. True

• B. False

Multiple Choice

4. What kind of measure is shown in the photo below to respond to tropical cyclones?

• A. Preventive measure

• B. Remedial measure

HW:
1. whole typhoon booklet​
2. BK P.60-61: unit summary

​Summer monsoon