Scientists image gravity waves through atmosphere

© Hanli Liu, NCAR
A model simulation illustrates how gravity waves kicked off by a cyclone east of Australia build as they travel toward space.

    

Whether it's a drunk camper diving carelessly into a river, or a mass of air rising over a mountain, the rule is the same: What goes up must come down.

With respect to the latter, the rising and falling of air also generates gravity waves. While such atmospheric changes usually only have a regional impact on the lower atmosphere, these ripples can stretch all across the globe in the upper atmosphere and their impact is far more dramatic.

For the first time, researchers have found a way to observe what happens when gravity waves rise towards into the upper atmosphere. A team of researchers at the University Corporation for Atmospheric Research led by Senior Scientist Hanli Liu improved upon the Whole Atmosphere Community Climate Model, pushing it to a resolution fine enough to pick up small gravity waves at their source.

Previously able to clearly view only phenomena that were 2,000 kilometers across, they are now able to view gravity waves when they are still relatively small—only 200 kilometers across—and accurately model how this activity appears later in the upper atmosphere.

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I sense a disturbance in the force

And since disturbances in the upper atmosphere (usually attributed to solar activity) are what can damage satellites, shut down radio transmissions, skew GPS signals, and in this high-tech day and age basically just , modeling like this is exactly what we need to understand the Earth's role in these disturbances.

"When gravity waves propagate to the bottom side of the ionosphere, they can kick off instabilities," Liu said. "If you want to have a better understanding of space weather—the ionosphere—you need this kind of modeling capability."