Download Global Distribution of Temperature Teachers` Notes Level S4

Global Distribution of Temperature
Teachers’ Notes
Level
S4-S6
Duration
20 minutes
Learning Objectives
1. To understand the global distribution pattern of temperature
2. To understand the factors affecting the global distribution pattern of temperature
Curriculum Links
Geography (Secondary 4-6) Compulsory Part --7. Global Warming — Is it fact or fiction?
Global distribution pattern of temperature and reasons for the latitudinal differences in the
distribution of insolation.
* Other factors affecting the distribution of temperature: land and sea, ocean current, prevailing
winds and relief
* Temporal distribution pattern of global temperature
Contents of the Programme:
This programme illustrates how latitudes affect the distribution of insolation. It points out that if the
Earth was a smooth prefect sphere made entirely of the same material, latitudes would be the sole factor
determining the amount of insolation received at various locations. Surfaces with the same latitude should
be at the same temperature, hence, the lower the latitude, the higher the temperature; conversely, the higher
the latitude, the lower the temperature. However, that is not the case. The Earth is not a uniform sphere, and
on its surface, there are mountains, plains, oceans and land. In addition, the atmospheric components, such
as moisture and dust, of the various areas are all different. These factors also affect the temperature
distribution pattern.
The programme uses the following cases to explain how various factors affect the distribution of
temperature as follows:
Cases
Factors affecting the distribution of temperature
To compare the temperatures between the two
European cities, Leeming of the UK and Ufa of
Russia, which are both located at around 54
degrees North Latitude.
Distance from the sea
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To compare the temperature between Beijing of
China and Rome of Italy, which are both are located
Wind
at around 40 degrees North Latitude.
To compare the temperature between Vancouver of
Canada and Poronaysk of Russia, which are both
located at around 49 degrees North Latitude.
Ocean Current
To compare the average annual insolation between
regions around the equator and regions around the
Tropic of Cancer.
Cloud Cover
To observe the distribution pattern of isotherms in
the western part of South America (The Andes).
Altitude / Relief
To compare the height of the snowlines between the
Aspect
southern and northern sides of Mt. Fuji.
How to use this programme
The following suggestions are for teachers’ reference only and may be adjusted according to classroom
situations.
1. Factors affecting temperature distribution are introduced in different sessions in the programme.
Teachers may use the corresponding parts to explain each factor as appropriate.
2. The programme invites students to think about the following phenomena:
a) Why are the isotherms around the northern part of India (Area A in the figure below) closely spaced?
b) Why do the isotherms become sparsely spaced towards the North (Area B in the figure below)?
Distribution of temperature (°C) over the northern part of India in January
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These phenomena can be explained by the factors, Altitude and Relief.
a) Area A is the Himalayas which is the highest mountains on Earth. As the altitude increases,
temperature drops according to the Environmental Lapse Rate. Because the Himalayas rises sharply
from the Gangetic Plain, the temperature drops drastically from the lowland up to the mountains.
The great temperature gradient results in the isotherms in northern India seemed closely spaced.
b) Area B is Tibetan Plateau which is a vast elevated tract of relatively flat land. With a small altitude
difference, the temperature gradient is small between the mountains and plateau, so the isotherms at
the northern slope of the Himalayas are relatively sparsely spaced.
Teachers may further explain the concepts to the students with a topography map.
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