Topics Earth, weather and climate

Why is Antarctica colder than the Arctic?

Antarctica is colder mainly because of what it is made of and how high it sits. Antarctica is a continent, and its ice sheet raises the surface to roughly 2 kilometers above sea level on average. Air cools as you climb, so the ground itself is high and cold. The Arctic is mostly a floating sea of ice over ocean, close to sea level, and that water holds and passes along heat.

The sun is not the answer. Earth is actually farthest from the sun during the southern winter, but the distance changes the sunlight only slightly, and it does not explain the gap. What does matter is a mix of causes: elevation, the ocean around each pole, winds and currents that wall Antarctica off from warmer air and water, and bright ice that reflects sunlight. That bright surface is more extensive and lasts longer in Antarctica, and it adds to the cold rather than being the main cause. Scientists still study how much each factor contributes.

An episode on bre would walk through those pieces one at a time and compare the two poles side by side. bre's hosts are AI, so they can be wrong, and you can press Talk to ask a question mid-episode.

What a bre episode would cover

An outline of the episode bre would make for this question. Every episode is written fresh when you ask, so yours will differ.

  1. Two poles, two kinds of groundThe Arctic is an ocean mostly covered by floating sea ice, ringed by land. Antarctica is a continent under a thick ice sheet, ringed by ocean.
  2. Height makes coldAir gets colder with altitude. The ice sheet lifts Antarctica's average surface to roughly 2 kilometers above sea level, and the ice at the South Pole is about 1.7 miles thick.
  3. The Arctic's ocean heaterWater stores heat and moves it around. Even under sea ice, the Arctic Ocean releases some warmth and draws in more from nearby seas, which softens winter.
  4. Walls of wind and waterStrong winds and the Antarctic Circumpolar Current circle the continent and limit how much warm air and water reach it. The Arctic is more open to warm intrusions from the south.
  5. Bright iceSnow and ice reflect much of the sunlight that reaches them, and Antarctica's ice cover is more extensive and lasts year-round. It adds to the cold, though it is not the primary cause.
  6. What the records showThe coldest temperature ever measured on Earth, about -89 degrees Celsius, was recorded at Vostok Station in Antarctica. Nothing measured in the Arctic comes close.

How the episode might open

A sample exchange between two of bre’s AI hosts, bre and Tess. Both are AI; this is written by AI, as every bre episode is.

  1. breAI host

    Both ends of the planet are called poles, and both are frozen. But very different ground sits underneath. So why does one of them win the title of coldest place on Earth?

  2. TessAI host

    Okay, but real talk: most people guess it's the sun. Antarctica must be farther away, or tilted worse. Is that it?

  3. breAI host

    It's a fair guess. Earth is actually a little farther from the sun in southern winter, and that adds a small effect, but the difference in sunlight is small and it doesn't explain the gap. The real gap is on the ground.

  4. TessAI host

    So what's different about the ground?

  5. breAI host

    Antarctica is a continent, and in many places it's buried under a mile or more of ice, about 1.7 miles at the South Pole. You're standing thousands of feet up. The Arctic is mostly floating sea ice over ocean, right at sea level.

  6. TessAI host

    So one pole is a mountain plateau and the other is a frozen pond. Which sounds colder when you put it that way.

  7. breAI host

    Pretty much. Height makes air colder, and the ocean under the Arctic ice holds heat. Okay, here's the part nobody tells you: scientists are still working out how much each cause counts.

  8. TessAI host

    Good. I'd rather hear that than a tidy answer that's secretly a guess.

Questions people also ask

Which pole is colder, the North or the South?
The South Pole, by a wide margin. Antarctica holds the lowest temperatures ever recorded on Earth, far below anything measured in the Arctic. Average temperatures there are much lower too, largely because the continent is high, covered in ice, and cut off from warmer air and water.
Is Antarctica farther from the sun than the Arctic?
Not in any way that explains the difference. Earth's distance from the sun varies slightly through the year, and it is farthest in early July, during the southern winter. That effect on sunlight is small. Elevation, ocean and the surrounding winds and currents matter much more.
Why does the Arctic stay warmer if it also has ice?
Arctic ice floats on an ocean, and water stores and carries heat. That ocean sits near sea level and exchanges warmth with surrounding seas and air. Antarctica's ice rests on a continent and rises high, so its surface sits in much colder air.
Does elevation really make that much difference?
Yes. Air temperature generally falls as you go higher, and Antarctica's ice sheet raises its average surface to roughly 2 kilometers above sea level. That height is a major reason the interior is so cold, though it works together with other factors rather than alone.

Related topics

More: all 300 topics, earth, weather and climate, or the longer reads on /learn.

bre’s hosts are AI, and every episode is generated, so they can be wrong: check anything that matters. This page outlines what an episode would cover. It is for interest and learning, not medical, financial or legal advice.