Unit 2 (2) - Factors affecting temperature Flashcards
(11 cards)
Factors affecting temperature?
Latitude
Altitude
distance from the sea
How does altitude affect temperature?
At higher altitudes, there is less water vapour,
dust & other impurities to absorb heat to warm the air.
Thus, temperatures drop with increasing altitude by 6.5°C for every 1000 m increase in altitude.
Also at higher altitudes, there is a smaller area
of land, which radiates back less heat to the
atmosphere.
Effect of altitude on temperature? HOW
At higher altitudes:
Heat escapes rapidly because air is rarefied
(contains little vapour & dust) to trap the
heat, thus lowering the temperature at higher
altitude
At lower altitudes:
Heat escapes from surface slowly because higher concentration of gases, water vapour and dust at the lower altitudes trap heat, thus increasing the temperature at lower altitude.
Full explanation of altitude affecting temp.
At higher altitudes, there is less water vapour, dust and other impurities to trap the heat. The lower concentration of gases will also
result in heat escaping back into space. Thus, temperatures drop with increasing altitude by 6.5°C for every 1000 m increase in height.
At the lower altitudes, air density is higher as atmospheric gases are most present at the lower altitudes due to the force of gravity. This also means that the atmosphere is more able to absorb and radiate heat, which
results in higher temperatures compared to the higher altitudes.
How types of surfaces (man-made materials) affect temperature at specific sites?
Man-made materials such as asphalt and concrete absorb and release the
heat from sunlight quickly to the air above it. This results in higher temperatures in the day where the roads are.
Though some tall buildings can provide shade during the day and may lower temperatures at the ground, the heat that is absorbed by the concrete materials will be emitted at night, thus increasing temperatures.
Therefore, high temperatures are experienced in sites such as urban locations
(cities) with densely built-up areas of buildings and road networks.
How types of surfaces (vegetation) affects temperature at specific places?
Vegetation cover such as trees can reflect the Sun’s rays before they reach the ground.
The trees provide shade by intercepting or absorbing the Sun’s rays.
In the day, grass and soil absorb heat from the Sun’s rays but release them slowly
because they have low heat conductivity.
Vegetation release water vapour through transpiration, causing evaporative collection.
Hence, all these result in lower temperatures at sites with vegetation cover, for example, in
a park or forest.
How types of surfaces (man-made heat sources) affect temperature at specific sites?
Man-made heat sources such as vehicles and air-conditioners release waste-heat
when they are in use.
Vehicles also release exhaust fumes with gases such as carbon dioxide, which is a
greenhouse gas, that traps heat.
An Aircon unit transfers warmth from inside buildings to the air outside and as it uses
electricity, it also generates waste-heat that is vented out too.
Therefore, higher temperatures are experienced in sites such as urban locations (cities).
How types of surfaces (water bodies) affects temperatures in specific places?
Water in surface storage, such as ponds, absorb and release heat slower than land surfaces in the day due to poor conductivity. The air above the pond is much cooler, hence decreasing the temperature near it in the day.
As water in the pond is heated and turns into water vapour, this results in evaporative collection in the day.
Hence, all these result in lower temperatures at sites near water bodies such as
a reservoir, pond, sea or river.
How types of surfaces (difference in colour of Earth’s surfaces) affects temperature in specific places?
Dark-coloured surfaces e.g. asphalt
roads absorb more heat from the
Sun’s rays and radiate more heat.
This causes faster heating up of the
air above it, resulting in higher
temperatures.
Light-coloured surfaces, e.g. icy
surface reflects less heat from the
Sun’s rays and radiate less heat.
This causes slower heating up of the
air above it, resulting in lower
temperatures.
Urban areas comprise larger areas of dark surfaces experience higher
temperatures than sites with vegetation and water bodies.
How distance from the sea affects temperature in specific places?
During summer, the air over the sea is cooler than the air over the land. This is because
land heats up quickly while the sea heats up slowly. When the wind blows landwards, the cooler air over the sea helps to reduce the
temperature at coastal areas. Coastal locations experience warm summers instead of hot
summers.
During winter, the air over the sea remains warmer than the air over the land because the sea cools slower than the land. When the wind blows landwards, the warmer air over the sea
increases the temperature of coastal areas. Coastal locations experience cool winters instead of cold winters.
The Maritime Effect results in coastal
locations having a small annual
temperature range.
