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The polar regions surround Earth’s North and South Poles. The area around the North Pole is called the Arctic. The area around the South Pole is called Antarctica. These regions have unique climates.
Polar regions are very cold. This is because they get less direct sunlight than other places on Earth. The Earth rotates around the sun. But the sun doesn’t reach all parts of the Earth in the same way. The area around Earth’s equator gets a lot of sunlight in a small area (b). Sunlight hits the polar regions at a shallow angle. This means the same amount of light is spread out over a larger area (a).
Because they receive less concentrated sunlight, polar regions are much colder than other parts of the planet. In the summer, the average temperature at the North Pole is 0° C. In the winter, the average temperature drops to −40° C. The South Pole is even colder. The average temperature in the summer is −28.2° C. In the winter it’s −60° C.
People have to dress very warmly when they go outside in these conditions. Frostbite can develop in minutes. Frostbite happens when your skin freezes. The cold also makes car engines stop working properly. People use plug-in heaters to make sure their cars will start after sitting outside in the cold.
There are no permanent residents of Antarctica. But people have been living in the Arctic regions of North America, Europe, and Asia for thousands of years. These diverse Indigenous communities have developed cultural practices that help them live off the land. These include ways of hunting, fishing, and making clothing in extreme weather conditions.
Many of these practices are now threatened. Climate change and social change can make it more difficult for Indigenous people to practice these ways. Especially because many Indigenous communities are marginalized.
Seasons in the Polar Regions
Earth has seasons because its axis is titled as it rotates around the sun. This means that the amount of sunlight polar regions get changes a lot between summer and winter.
In summer, the Northern hemisphere tilts towards the sun. This means regions around the North Pole receive many hours of sunlight every day. In winter, the Northern Hemisphere tilts away from the sun. This means the regions around the North Pole receive very little sunlight.
In some places near the poles, the sun doesn’t rise for many weeks in the winter. And the sun doesn’t set for many weeks in the summer.
Polar regions in the Southern hemisphere experience these same seasonal shifts at opposite times of the year. For example, June is summer in the Northern Hemisphere and winter in the Southern Hemisphere.
People who live in polar regions adjust to these changes. During the summer, people might enjoy the midnight sun with late night barbeques. In the winter, some people adjust to 24-hour darkness by sleeping more. They may also celebrate when the sun returns after weeks of darkness, with a sunrise festival.
Did you know?
Inuvik, a town in the Northwest Territories, receives 24 hours of sunlight a day during a lot of June and July. But the sun doesn't rise at all during most of December.
Landforms in Polar Regions
We often think of deserts as being hot. But parts of polar regions are also classified as deserts too. The air in polar regions is very dry. This is because of the very cold temperatures. Because there isn’t much moisture in the air, there aren’t many clouds or rain and snow. Some polar regions get less than 25 cm of precipitation per year. This is what makes them deserts!
Did you know?
Antarctica is the largest desert on Earth. Many parts of the Sahara desert get twice as much precipitation as Antarctica each year.
Near the North and South Poles, the temperatures can be so low that when snow does fall, it doesn’t melt. Instead, the snow builds up slowly over millions of years. In some places, the weight of many years of snow compresses it into large masses of ice. These are called glaciers. Glaciers flow, or move at very slow speeds. This is because they contain so much ice.
Ice sheets are large glaciers. They are larger than 50 000 square kilometers. Right now, there are only two ice sheets on our planet. One is in Antarctica and one is in Greenland. But thousands of years ago, much more of the Earth was covered with ice sheets. Today, Antarctica is covered by the largest ice sheet on Earth. It is more than 14 million square kilometers. Greenland is covered by a much smaller ice sheet.
Ice caps are small glaciers. They cover less than 50 000 square kilometers. Ice caps are usually dome-shaped. Both ice caps and ice sheets are made of fresh water. This water fell as snow and compacted over time.
Ocean water stays liquid at much colder temperatures than fresh water. The temperature in polar regions sometimes drops low enough for a thin layer of water to freeze. This is called sea ice. It covers about 15 percent of the world’s oceans during part of the year. Some sea ice in polar regions never melts. This means it can get up to about 30 metres thick.
Which pole is colder?
Sunlight is not the only thing that affects the temperature in the polar regions. The South Pole is much colder than the North Pole even though they both get the same amount of sunlight.
The Arctic is warmer because it’s mostly ocean. The Antarctic is colder because it’s mostly land. Even though the Arctic Ocean is very cold, it’s warmer than the ice. It also warms the air above it. But Antarctica is made up of frozen land and high mountains. This is why the northern polar regions are warmer than the southern polar regions.
Climate Change in the Polar Regions
Global warming affects the polar regions more than other parts of the world. In the past 30 years, temperatures in the Arctic have risen about twice as much as average temperatures on Earth. Temperatures are rising so quickly that the Arctic could have no summer sea ice by 2035. In Antarctica, similar changes are happening. Ice sheets are melting, even in the coldest regions.
These changes are happening quickly because of feedback loops. A feedback loop happens when some of the output of a system comes back into a system as input.
When sea ice melts in polar regions, water is exposed. The water is darker than the ice, so it absorbs more heat. Water also reflects less light than ice. The extra heat absorbed by the water causes even more ice to melt. This feedback loop means the arctic is warming faster than it would otherwise. Feedback loops that include melting ice are causing rapid climate change in polar regions.
Climate change in polar regions affects the whole planet. White ice and snow reflect the sun’s heat. When there is less snow and ice, less heat will be reflected. This contributes to rising temperatures worldwide. And melted ice and snow contributes to rising sea levels. Finally, when permafrost melts, large amounts of stored methane are released. Methane is a greenhouse gas that can prevent heat from leaving Earth’s atmosphere. More methane contributes to global warming. Even though polar regions may seem far from other parts of our planet, they are deeply connected to our global climate systems.