3.6 Polar climates

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3.6 Polar climates (vwo)

Learning objectives

After studying this section, you will be able to:

• Describe the polar climates
  
• Explain the location of the polar climates

Polar climates and landscapes

Three types of polar climate: 

• Tundra climate (ET)
• Ice cap climates (EF) > high latitude
• Mountain ranges (EH) > high altitudes

The tundra climate has at least one month in which the temperatures are higher than 0 °C, but none of the months is warmer than 10 °C. In the ice cap climate, the temperature never exceeds 0 °C. The tundra climate does experience precipitation, but the ice cap climate is quite arid.

The tundra climate has at least one month in which the temperatures are higher than 0 °C, but none of the months is warmer than 10 °C.

A tundra pond in the summer months - surface snow melts, forming a freshwater pond.

In the ice cap climate, the temperature never exceeds 0 °C and it's quite arid.

Which climate does the graph show?

1. Tundra climate (ET)
2. Ice cap climate (EF)

Which climate does the graph show?

1. Tundra climate (ET)
2. Ice cap climate (EF)

Which climate does the graph show?

1. Tundra climate (ET)
2. Ice cap climate (EF)

Tundra climate (ET)

Ice cap climate (EF or EH)

High latitudes

At high latitudes, the cold temperatures can be explained by the small amount of sunlight that reaches the Earth. In fact, during the winter season the sunlight does not reach the polar regions at all, because the hemisphere is turned away from the Sun. The solar energy that does reach the Earth’s surface is spread out over a large area (see section 3.2).

The Albedo Effect

The Earth’s albedo, or reflectivity, is another reason why temperatures in the polar regions are low: white snow is a good reflector of sunlight, so not much gets absorbed. As a result, the temperature in the region does not increase significantly when sunlight does reach the polar region in the summer season.

High altitudes

•  The temperature drops around 1 °C per 100 metres of altitude rise, if the air is dry. In humid air the air temperature drops more slowly at 0.6 °C per 100 metres.
  
• High in the mountains, the low temperature is explained by the lower air pressure. As you are higher up in the mountains, less air is pressing down on you: the air pressure drops. As the air pressure decreases, the air temperature decreases as well.

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The changing polar climate

• Temperatures in the Arctic and Antarctic are increasing faster than in other regions. 
• Effect on a regional scale: melting permafrost > buildings that were built on the once frozen soil have slowly started sinking, leading to cracks in the buildings.
  
• On a global scale, melting permafrost impacts the climate: scientists have found that the permafrost stores large quantities of methane. Methane is a greenhouse gas. More greenhouse gases in the atmosphere will warm the climate even further.

Essence

Polar climates are characterised by very low temperatures. There are two types of polar climate: the tundra climate and the colder ice cap climate. Both climates can be found at high latitudes, around the poles. The ice cap climate can also be found on the top of mountains. As a result of the polar climate, landscapes are often covered in snow. In regions with an ice cap climate, it is too cold for plants to grow. Nevertheless, people inhabit these cold areas: they have adapted their lifestyle to the freezing temperatures.

Look at the planner in Teams for the homework!