Arman Alluwie TP2 SHSS 1

Intro to Weather and Climate: Temperature

2

Lesson objectives

• By the end of the lesson, we will be able to– differentiate between weather and climate– describe temperature as an element of weather– describe the factors affecting temperature

3

Singapore Weather?

http://www.youtube.com/watch?v=lKa6brIbdYo

4

Weather or Climate?

Sentence describes … W or C?Some plantation crops like rubber, coffee and oil palm are grown in places that are hot and wet.

It has been snowing these past few days.

There are many ships docked in the harbor because of the impending storm.

C

W

W

5

Weather or Climate?Sentence describes … W or C?A large number of Europeans leave their countries for holidays during the months of October to December in order to escape winter.

Heavy thunderstorms are expected over the northern and western parts of Singapore for the next two weeks.

The hot and wet conditions in tropical countries like Singapore support the growth of vegetation all year round.

C

C

W

6

Weather or Climate?

• Weather– conditions of the atmosphere at a specific place

over a relatively short period of time– Changes from day to day

• Climate– average weather conditions of a specific place

over a considerable period of time, usually 30 to 35 years

Weather VS Climate

Condition of the atmosphere at a particular place over a short period of time

Weather

Weather pattern of a place over a long period of time, usually >30 years

Climate

8

Elements of Weather

Temperature

Latitude

Altitude

Distance From The Sea

Cloud Cover

Relative Humidity

Condensation

Saturation

Evaporation

Precipitation

Convectional Rain

Relief Rain

Pressure and Winds

Sea Breeze

Land Breeze

Monsoon Winds

Arman Alluwie TP2 SHSS 9

Elements of Weather:Temperature

• degree of hotness and coldness of a place• affected by the amount of Sun’s rays that

reaches Earth’s surface– latitude– altitude– distance from the sea– cloud cover

Factors Influencing Temperature

• Latitude: the distance (in degrees) to the north and south of the Equator

• Q: Why are temperatures at the Poles & Equator different? – Hint: It has something to do with the shape of the Earth!– A: The Sun’s rays travel different distances & strike the

Earth’s surface at different angles.

11

Temperature:Latitude

Latitude

warmer

cooler

cooler

12

Temperature:Latitude

short long

Q: Why are temperatures at the Poles & Equator different?

• Sun’s rays travel different distances & strike Earth’s surface at different angles uneven distribution over Earth’s surface!– Higher concentration on/near Equator (LOW LATITUDE)

• Sun rays strike Earth’s surface perpendicularly!• They travel shorter distance spread over small area of land

– Lower concentration near the poles (HIGH LATITUDE)• Sun rays strike Earth’s surface at an angle!• Sun rays travel longer distance & directed over bigger area of land.• Absorbed by atmosphere / reflected back into outer space

Equator Sun’s rays

Sun’s rays

Sun’s rays

2a. Factors Influencing Temperature

• Altitude: the height of a point above the sea level

• Temperature decreases as altitude increases.– Normal Lapse Rate / Adiabatic Lapse Rate: On

average, temperature falls by about 6.5C for every 1,000 metres increase in altitude.

• Q: Why?

2a. Factors Influencing TemperatureAltitude• Places near the sea level (low altitude)

are warmer – Earth’s surface absorbs heat from the Sun

directly (larger land surface area)– and heats up the dense air above it through

conduction

• Places further away from the sea level (high altitude) are cooler – Air is thin smaller concentration of gas, dust

and water vapour to trap heat– Smaller land surface area for conduction

• e.g. Genting Highlands, Cameron Highlands

16

Temperature:Altitude

at lower ground there is a larger area of land, much warmer at lower ground

20°C

7.2°C

17

Temperature:Altitude

6000

0 sea level

2000

4000

concentration of gases

incr

easi

ng g

ravi

tatio

nal p

ull

m

18

Temperature:Altitude

6000

0 sea level

2000

4000

absorbs more heat

absorbs less heat

heat transferred byconduction and convection

m

2a. Factors Influencing Temperature

• Distance from the sea: the difference in the rate of heating and cooling of land and sea has an effect on the temperatures of coastal areas.– Land heats up and cools down

more quickly than the sea.

• Q: Why?

20

Temperature:Distance from the Sea

• how coastal areas are affected by the difference in the rate of heating and cooling of land and sea

• Near to the sea – Maritime effect– Definition: the effect that large ocean bodies have on the climate

of coastal areas• Q: Summer and winter?

Coastal areas experience cooler summers & warmer winters due to the maritime effect.

They have a smaller temperature range at an annual scale.

Land Sea

Summer Air heats up quickly

Air gains heat slowly

Winter Air loses heat quickly

Air loses heat slowly

• Far from the sea – Continental effectDefinition: the effect that continental surfaces have on the

climate of inland areas far away from the sea Inland areas experience warmer summers and cooler winters

as they are not influenced by the sea.These places have a larger temperature range at an annual

scale.

Land

Summer Air heats up quickly

Winter Air loses heat quickly

23

Temperature:Distance from the Sea

Water Bodies

Concept: Water bodies heats up and cools down slower

Land bodies

S L O W E R

24

Temperature:Distance from the Sea

Water BodiesLand bodies

S L O W E R

Summer, air heats up quickly air heats up slowly

relatively cool

25

Temperature:Distance from the Sea

Water BodiesLand bodies

S L O W E R

Winter, air cools down quickly air cools down slowly

relatively warm

Temperature of Singapore VS Sahara Desert at night?

• Cloud cover: the amount of clouds over an area• Influences the amount of solar radiation

entering/leaving the atmosphere.Places with more cloud cover smaller difference in day &

night temperatures. Places with less cloud cover larger difference in day &

night temperatures. (e.g. deserts)

Presence of clouds Absence of clouds

Day Less solar radiation absorbed by land

More solar radiation absorbed by land

Night Less heat escaping into outer space

More heat escaping into outer space

2a. Factors Influencing Temperature

You have learnt to:

1. differentiate between weather and climate2. describe the elements of weather

• temperature

3-2-1!

• 3 things that you learned from this lesson• 2 things that you are not so sure about• 1 thing you are still curious about and would

want to know more