F.6 Core 7 Factors affecting insolation

​This elective introduces three fundamentally important properties of the atmosphere, namely heat, moisture and motion. By using Hong Kong and other places in the Mainland as examples, students learn about the basic weather elements and how climate varies with location and time. They also study the interrelationship between climate and human activities, specifically about how climate influences human activities and how human responds to these influences.

​Weather and Climate

Fill in the Blanks

Where do our source of heat come from?

F.6 Elective 2
What happens when solar radiation reaches the earth?

Multiple Choice

The sun is constantly releasing energy in all directions. This incoming solar radiation that is received in the atmosphere or on the earth’s surface is known as insolation. It is a kind of ___________.

• short wave radiation

• long wave radiation

• counter radiation

Multiple Choice

The global distribution of insolation on the earth's surface is _(A)_.

• uneven

• even

Fill in the Blanks

The global distribution of insolation on the earth's surface is uneven. Despite some location variation, insolation received declines with increasing

.

Why does the insolation received varies with latitudes?
Why doesn't it the same everywhere on earth?

The angle of the sun varies with latitude.

Draw

Circle the largest angle of sun in the diagram.

Multiple Choice

Where does this larger angle of sun can be found?

• low latitude region

• high latitude region

​larger

Multiple Choice

The area that can warm up by A is _____.

• larger

• smaller

Multiple Choice

The intensity / concentration of insolation of Ray A is ____.

• higher

• lower

Multiple Choice

The angle of the sun of Ray B is ____.

• larger

• smaller

Multiple Choice

The area that can warm up by B is _____.

• larger

• smaller

Multiple Choice

The intensity / concentration of insolation of Ray B is ____.

• higher

• lower

TO conclude, the lower the latitude, the larger the angle of the sun, insolation received is more concentrated over a smaller area. The intensity of insolation is higher.

The angle of the sun does not just vary with latitudes, it also varies with time of day.

Fill in the Blanks

The angle of the sun varies with time of day.

The insolation is the most intense at

during the day.

Does the angle of the sun the same throughout the whole year?

Where is the overhead sun? Is the location of overhead sun always the same throughout the year?

Hotspot

Point out where the overhead sun is located during the Spring equinox.

Multiple Choice

The overhead sun in summer solstice is at ___.

• The equator

• Tropic of Cancer

• Tropic of Capricorn

Multiple Choice

The overhead sun in autumn equinox is at ___.

• The equator

• Tropic of Cancer

• Tropic of Capricorn

Multiple Choice

The overhead sun in winter solstice is at ___.

• The equator

• Tropic of Cancer

• Tropic of Capricorn

So since the earth is titled towards the sun, during its rotation and revolution (which is from west to east), the angle of the sun may vary and affect the amount of insolation we receive.

This produces seasons.

Thus, even we are staying in the same place, like HK, the insolation we receive during different period in the year is different. (more intense insolation in summer because the angle of the sun is larger; while less intense insolation in winter, because the angle of the sun is smaller.)

Factor 2: Duration of daylight

The longer the daytime, the more the insolation we receive.
Do we have longer day in summer? or winter?
Do we receive more insolation in summer? or winter?

https://players.brightcove.net/6144772950001/default_default/index.html?videoId=6182383004001

Duration of daylight in Spring equinox (21/22 Mar)

Multiple Choice

The diagram shows the duration of daylight in ____.

• Spring equinox (21/22 Mar)

• Summer solstice (21/22 June)

• Autumn equinox (22/23 September)

• Winter solstice (21/22 December)

Duration of daylight in Autumn equinox (22/23 September)

Multiple Choice

The diagram shows the duration of daylight in ____.

• Spring equinox (21/22 Mar)

• Summer solstice (21/22 June)

• Autumn equinox (22/23 September)

• Winter solstice (21/22 December)

Duration of daylight varies with seasons. The longer the duration of daylight, the more the insolation receives.

Multiple Choice

Past paper 2018 DSE Q38

• A

• B

• C

• D

Multiple Choice

Past paper Practice paper DSE Q40

• A

• B

• C

• D

Multiple Choice

Past paper 2010 CE Q11

• A

• B

• C

• D

Multiple Choice

Past paper 2007 CE Q14

• A

• B

• C

• D

c. The atmosphere

Are we receiving all the insolation from the sun?

c. The atmosphere

Use a ruler to measure distances (a) and (b) in the diagram. What can you find out?

Multiple Choice

What is A?

• longer

• shorter

Multiple Choice

What is B?

• longer

• shorter

Multiple Choice

In general, the longer the distance the sun’s rays have to travel through the atmosphere, the X the loss of insolation.

• greater

• smaller

reflection, scattering, abosption 

greater

Refer to the Map on p.1 again. Although in general, insolation receives decreases with increasing latitudes, the maximum insolation received is NOT along the equator. Can you explain why?

Fill in the Blanks

Why not the equator?

It is because near to the equator, it's an area with extensive

(natural landscape).

Fill in the Blanks

With large amount of rainforests, _ _ _ _ _ cover is thicker in the atmosphere.

Multiple Select

With large amount of rainforests, cloud cover is thicker in the atmosphere. Thus more insolation is loss through

• reflection

• scattering

• absorption

• precipitation

Multiple Select

So where does higher insolation received?

• around Tropic of Cancer

• around Tropic of Capricorn

• around Arctic Circle

• around Antarctic Circle

The amount of radiation reflected depends on the reflectivity of the earth's surface, called the albedo.

Multiple Choice

What can we find in the polar regions?

• Fresh snow

• Forest

• Crops, grassland

• Asphalt, Concrete

• Water bodies

Multiple Choice

What can we find in the tropical rainforests?

• Fresh snow

• Forest

• Crops, grassland

• Asphalt, Concrete

• Water bodies

Multiple Choice

What can we find in the urban area?

• Fresh snow

• Forest

• Crops, grassland

• Asphalt, Concrete

• Water bodies

Multiple Choice

What can we find in the rural area?

• Fresh snow

• Forest

• Crops, grassland

• Asphalt, Concrete

• Water bodies

Multiple Choice

What can we find in the ocean?

• Fresh snow

• Forest

• Crops, grassland

• Asphalt, Concrete

• Water bodies

Order from highest to lowest: Fresh snow > Water > Grass > Crops > Forests > Concrete > Asphalt 

Multiple Choice

Which slope is the north facing slope in the Northern Hemisphere?

• A

• B

Multiple Choice

Which slope receives more insolation in the Northern Hemisphere?

• South facing slope

• North facing slope

Fill in the Blanks

The south facing slopes in the Norther Hemisphere receive more insolation. It is because the

is larger.

​intense

Open Ended

Which slope would receive more insolation in the southern hemisphere? Write a paragraph below to answer the question.

Multiple Choice

past paper 2020 DSE Q20

• A

• B

• C

• D

Multiple Choice

past paper 2016 DSE Q37

• A

• B

• C

• D

Multiple Choice

past paper 2015 DSE Q38

• A

• B

• C

• D

Multiple Choice

past paper 2013 DSE Q36

• A

• B

• C

• D

Multiple Choice

past paper 2006 CE Q37

• A

• B

• C

• D

Multiple Choice

past paper 1997 CE Q25

• A

• B

• C

• D

If we continue to receive energy from the sun, does it mean that we will become hotter and hotter everyday?

Do you think energy will leave the earth too? How?

​What is earth's radiation budget?

Radiation budget / Energy budget is a balance between
incoming and
outgoing energy.

Multiple Select

Do you still remember what will happen to insolation when it passes through the atmosphere?

• some of it is reflected

• some of it is scattered

• some of it is evaporated

• some of it is absorbed

​23 units

​57 units

​48 units

​48

48 units​

​23 units

​48 units

​11 units

11 units

68 units

32 units

​Is the energy budget of the atmosphere balanced?

​Is the energy budget of the atmosphere balanced?

Yes.

It is because the incoming energy (from sun and earth's surface) is equal to the outgoing energy (to space).

The end