Surreal illustration of Earth's atmosphere, showing the Quasi-Biennial Oscillation

Decoding the Quasi-Biennial Oscillation: How This Atmospheric Phenomenon Affects Your Weather

Jordan Keane in Science & Nature August 2025 • 4 min read.

"Understanding the QBO's impact on global weather patterns, from polar vortex shifts to tropical rainfall, could unlock better long-term forecasts."

Have you ever wondered why some winters are mild while others are brutally cold? Or why rainfall patterns seem to shift and change from year to year? While many factors influence our weather, one key player operates high in the atmosphere, largely out of sight but certainly not out of mind: the Quasi-Biennial Oscillation, or QBO.

The Quasi-Biennial Oscillation is a recurring pattern of alternating easterly and westerly winds in the equatorial stratosphere, about 10 to 50 kilometers (6 to 31 miles) above the Earth's surface. This isn't just some abstract meteorological phenomenon; it has far-reaching impacts on global weather patterns, affecting everything from the strength of the polar vortex to the intensity of tropical rainfall.

Recent research has shed new light on the QBO's complex teleconnections – its ability to influence weather events in distant regions. By understanding these connections, scientists hope to improve long-range weather forecasting and better prepare for extreme weather events. Let's dive into the science and uncover how this atmospheric oscillation impacts our daily lives.

The Science Behind the Oscillation

Surreal illustration of Earth's atmosphere, showing the Quasi-Biennial Oscillation

At its core, the QBO is driven by atmospheric waves that propagate upwards from the troposphere, the lowest layer of the atmosphere where our weather occurs. These waves interact with the stratospheric winds, causing them to alternate between easterly and westerly directions over a period of roughly 28 months. Several factors affect the nature of Quasi-Biennial Oscillation.

The QBO isn't a perfectly regular cycle. Its period can vary by several months, and the strength of the winds can fluctuate from one oscillation to the next. This variability makes it challenging to predict the QBO's exact behavior and its subsequent impact on weather patterns.

Polar Vortex Modulation: The QBO can influence the strength and stability of the polar vortex, a large area of low pressure and cold air surrounding the Arctic. A weaker polar vortex can lead to colder winters in North America and Europe.
Tropical Rainfall Shifts: The QBO affects rainfall patterns in the tropics, influencing the location of the Intertropical Convergence Zone (ITCZ), a band of heavy precipitation near the equator.
Mid-Latitude Weather: The QBO can impact mid-latitude jet streams, influencing storm tracks and temperature patterns across North America and Europe.
Teleconnections: These are the ripple effects of the QBO, reaching from the stratosphere to the surface and connecting seemingly unrelated weather events across the globe.

Recent studies have focused on separating the QBO's influence on the polar vortex from its other impacts on the troposphere, the lower part of the atmosphere where weather happens. Researchers are developing new techniques to isolate the QBO's 'polar route' – its direct effect on the polar vortex – from other pathways through which it affects weather. For example, research shows the QBO influences temperatures in the tropical and subtropical lower stratosphere by affecting wind patterns. These wind shears near subtropical jets then affect the cycle of mid-latitude weather.

Looking Ahead: Better Forecasts and a Deeper Understanding

As scientists continue to unravel the mysteries of the QBO, we can expect to see improvements in long-range weather forecasting. By incorporating the QBO's influence into climate models, forecasters can better predict seasonal temperature and precipitation patterns, helping communities prepare for extreme weather events. While the QBO is just one piece of the puzzle, understanding its role in shaping our weather is crucial for building a more resilient future.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.5194/acp-2017-1065, Alternate LINK

Title: Surface Impacts Of The Quasi Biennial Oscillation

Journal: []

Publisher: Copernicus GmbH

Authors: Lesley J. Gray, James A. Anstey, Yoshio Kawatani, Hua Lu, Scott Osprey, Verena Schenzinger

Published: 2017-12-11

Everything You Need To Know

What is the Quasi-Biennial Oscillation (QBO) and how does it work?

The Quasi-Biennial Oscillation (QBO) is a pattern of alternating easterly and westerly winds in the equatorial stratosphere, approximately 10 to 50 kilometers above the Earth. It influences global weather patterns, including the polar vortex and tropical rainfall. The QBO is driven by atmospheric waves propagating upwards from the troposphere, interacting with stratospheric winds, causing them to alternate directions roughly every 28 months. It's not perfectly regular; its period and wind strength vary, complicating predictions of its behavior and impact.

How does the Quasi-Biennial Oscillation (QBO) influence global weather patterns?

The Quasi-Biennial Oscillation (QBO) impacts several weather phenomena. It modulates the polar vortex, affecting winter temperatures in North America and Europe. It also shifts tropical rainfall patterns by influencing the Intertropical Convergence Zone (ITCZ). Additionally, the QBO impacts mid-latitude jet streams, influencing storm tracks and temperature patterns. These ripple effects, known as teleconnections, link the stratosphere to the surface, connecting seemingly unrelated weather events globally.

What are teleconnections in the context of the Quasi-Biennial Oscillation (QBO), and why are they important?

Teleconnections, in the context of the Quasi-Biennial Oscillation (QBO), refer to its ability to influence weather events in distant regions. The QBO's effects aren't limited to the equator; they extend globally, impacting phenomena like the polar vortex and tropical rainfall. These connections are complex and still being researched, but understanding them is crucial for improving long-range weather forecasting. For example, changes in the QBO can affect wind shears near subtropical jets, which subsequently influence mid-latitude weather patterns.

How are scientists using the Quasi-Biennial Oscillation (QBO) to improve weather forecasting?

Scientists are working to improve long-range weather forecasts by incorporating the influence of the Quasi-Biennial Oscillation (QBO) into climate models. By understanding the QBO's impact on seasonal temperature and precipitation patterns, forecasters can better predict extreme weather events and help communities prepare. Researchers are also focused on isolating the QBO's direct effect on the polar vortex from its other impacts on the troposphere to understand and predict its downstream influences on surface weather better.

In what ways does the Quasi-Biennial Oscillation (QBO) affect the polar vortex and, consequently, winter weather?

The Quasi-Biennial Oscillation (QBO) affects the polar vortex, a large area of low pressure and cold air surrounding the Arctic. When the QBO is in its easterly phase, it can weaken the polar vortex, making it more susceptible to disruptions. A weaker polar vortex can lead to outbreaks of cold air in North America and Europe during winter. Recent research is focused on separating the QBO's direct influence on the polar vortex from other pathways through which it impacts weather in lower latitudes.