top of page
Polar Atmosphere Phenomena
: Focusing on the Polar Vortex
기대역 웹페이지 6_edited.jpg

Tropospheric Polar Vortex

Problem 2: The Tropospheric Polar Vortex

The Tropospheric Polar Vortex is essentially the Jet Stream itself—a fast-moving band of wind that encircles the cold Arctic air. Unlike the vortex high up in the stratosphere, this one is in the troposphere (where we live) and directly dictates our day-to-day weather.

① When the Vortex is Strong (Stable Jet Stream)

A strong tropospheric vortex means there is a large temperature difference between the Arctic and the mid-latitudes. This temperature contrast acts like an engine, making the jet stream fast and tight.

  • Cause:

    • A significant temperature contrast between the Arctic and the mid-latitudes is maintained.

    • As a result, the mid-latitudes (including Korea, the US, and Europe) experience relatively mild and stable winter weather.

  • Impact on Mid-Latitudes:

    • The fast, tight jet stream acts as a strong barrier, preventing cold and warm air masses from mixing.

    • Frigid Arctic air is effectively "locked" in the north.

    • Result: The mid-latitudes (like Korea, the US, and Europe) experience mild and less volatile winter weather. Extreme events like cold waves and heavy snow are suppressed.

② When the Vortex Weakens (Wavy Jet Stream)

  • Cause:

    • Arctic Amplification: This is the primary driver. Due to global warming, the Arctic is warming 2-3 times faster than the rest of the planet.

    • As the Arctic warms, the temperature difference (the engine) shrinks, causing the jet stream to lose its strength and speed.

  • Impact on Mid-Latitudes :

    • The weakened jet stream becomes slow, lazy, and wavy, meandering deeply southward in large loops.

    • This leads to extreme cold waves, record-breaking heavy snow, and abnormally low temperatures.

    • Result (Volatility): Weather variability increases dramatically. When the cold wave ends, a ridge (the northward bulge) of the jet stream may move in, bringing sudden warming, heavy rain, or other extreme weather in its place.

A weakvortex means the temperature difference between the Arctic and the mid-latitudes has decreased.

bottom of page