Polar easterlies

Polar easterlies are cold winds that blow from east to west near the poles. In Intro to Climate Science, they are part of global atmospheric circulation and help move air around the polar cell.

What are polar easterlies?

Polar easterlies are the winds that blow from the east toward the west in the high latitudes near the Arctic and Antarctic. In Intro to Climate Science, they are part of the polar cell, the circulation loop that forms around each pole because very cold air sinks there and spreads outward at the surface.

The basic setup is simple: the poles receive less solar energy, so the air near the surface stays cold and dense. That air sinks, creating polar highs. From there, air moves outward away from the pole. As Earth rotates, the Coriolis effect bends that moving air, so what starts as an outward flow becomes an easterly wind at the surface.

These winds are usually weaker than trade winds or the westerlies, but they still matter. Near the surface, polar easterlies can push cold, dry air across sea ice and the ocean edge, which affects local temperature and cloud formation. They also help set up the boundary where polar air meets warmer air from lower latitudes.

That boundary is near the polar front, where the contrast between cold polar air and milder air farther south creates strong weather activity. Even though polar easterlies themselves are not a storm system, they help organize the larger circulation pattern that makes the polar regions behave differently from the tropics and midlatitudes.

Season matters too. In winter, the poles cool even more, the pressure difference grows, and the easterly flow can become more noticeable. In summer, the contrast weakens, so the winds often slacken. If you are tracing global circulation on a diagram, polar easterlies sit between the polar highs at the surface and the subpolar lows farther equatorward, completing the bottom part of the polar cell.

Why polar easterlies matter in Intro to Climate Science

Polar easterlies show you how climate is moved around by pressure, temperature, and rotation, not just by sunlight alone. In Climate Science, this term connects the polar cell to the rest of global atmospheric circulation, so you can see how the poles fit into the whole three-cell model with the Hadley Cell and Ferrel Cell.

The term also helps explain why the polar regions are not just cold, but dynamically different. Cold sinking air, surface divergence, and Coriolis deflection shape the winds that sweep over sea ice and the ocean margin. That matters when you are thinking about polar weather, ice formation, and the edge where polar air meets warmer air.

It also comes up when a lesson asks why weather systems move the way they do. If the polar easterlies shift or weaken, the position of the polar front and nearby storm tracks can change too. That gives you a clue for connecting local wind patterns to larger climate behavior, which is a big theme in intro climate units.

How polar easterlies connect across the course

polar cell

Polar easterlies are the surface wind branch of the polar cell. Cold air sinks over the poles, flows outward at the surface, and then is bent by Earth’s rotation. If you know the polar cell, you can place the easterlies in the circulation loop instead of treating them as a random wind pattern.

polar highs

Polar highs are the high-pressure zones that form because very cold air is dense and sinks over the poles. That sinking air spreads outward at the surface, which is the starting point for polar easterlies. Without the pressure pattern at the pole, the winds would not have the same direction or structure.

subpolar lows

Subpolar lows sit farther from the pole, where air tends to rise near the boundary between polar and midlatitude circulation. Polar easterlies move air away from the polar highs toward this region. On maps and diagrams, these lows help show where the polar easterlies fit into the pressure gradient.

coriolis effect

The Coriolis effect is what turns the outward-moving air into an easterly wind. In the Northern Hemisphere, moving air deflects to the right, and in the Southern Hemisphere, it deflects to the left. That deflection is why the winds are labeled easterlies instead of simply outward flow from the poles.

Are polar easterlies on the Intro to Climate Science exam?

A quiz item or short-answer question may show a global circulation diagram and ask you to label the wind belt near the poles. You would identify the polar easterlies, then explain that they blow from east to west because air moves outward from polar highs and gets deflected by the Coriolis effect. If the question gives a weather map, you may need to connect weak, cold surface winds near Antarctica or the Arctic to polar circulation rather than to midlatitude storms.

In a lab or data analysis task, you might compare wind direction with latitude and notice that the polar region has the opposite surface direction from the westerlies. In a written response, the best move is to link direction, pressure, and temperature: cold sinking air at the poles creates the pressure pattern, and that pattern helps organize the wind belt.

Polar easterlies vs westerlies

Polar easterlies and westerlies are often mixed up because both are global wind belts. The difference is direction and location. Polar easterlies blow from east to west near the poles, while westerlies blow from west to east in the midlatitudes. If you remember the latitude band, the naming makes more sense.

Key things to remember about polar easterlies

• Polar easterlies are cold surface winds that blow from east to west near the poles.

• They form when cold, dense air sinks over the poles, creating polar highs and outward surface flow.

• Earth’s rotation bends that flow, which gives the winds their easterly direction.

• Polar easterlies are part of the polar cell and fit into the larger global circulation pattern with the Hadley and Ferrel cells.

• They may be weak, but they still shape polar weather, sea ice conditions, and the boundary with warmer air.

Frequently asked questions about polar easterlies

What are polar easterlies in Intro to Climate Science?

Polar easterlies are the cold winds that blow from east to west near Earth’s poles. They are part of the polar cell in global atmospheric circulation. In climate science, they show how sinking air, pressure differences, and the Coriolis effect work together.

Why are polar easterlies called easterlies?

They are called easterlies because they come from the east. The air moves outward from polar highs, then Earth’s rotation deflects it so the surface wind travels westward. The name describes the direction the wind comes from, not where it is going.

How are polar easterlies different from westerlies?

Polar easterlies blow near the poles and move from east to west, while westerlies blow in the midlatitudes and move from west to east. They are different wind belts in the three-cell circulation model. If you confuse them, check the latitude first.

Where do polar easterlies show up on a climate diagram?

They appear in the high-latitude surface belt between the polar highs and the subpolar lows. On a global circulation diagram, look for the winds closest to the poles. That is the zone where cold air spreads outward and becomes easterly at the surface.