Watch invisible waves rumble through the atmosphere

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April 29, 2015 | Just as waves ripple across a pond when a tossed stone disturbs the water’s surface, gravity waves ripple toward space from disturbances in the lower atmosphere.

Gravity waves are born when air masses are pushed up or down—by a thunderstorm, perhaps, or when wind is forced up and over a mountain range—but in the lower atmosphere, their impacts usually remain regional. By the time they reach the upper atmosphere, however, the waves have built in amplitude and extent. There, they can dominate atmospheric processes on a much larger scale, sometimes threatening the reliability of Earth-based communication systems.

 

For the first time, scientists have simulated what gravity waves look like as they ripple upward through the atmosphere. This visualization, created on a supercomputer using a high-resolution version of the Whole Atmosphere Community Climate Model (WACCM), shows meridional (north-south) winds at two heights. The first segment shows winds at Earth's surface, where gravity waves usually have only regional impacts. The second segment shows winds at an elevation of 100 km (about 60 miles), where their influence can become dominant. The video simulations cover a three-day period when a hypothetical tropical cyclone was present off the east coast of Australia. (©UCAR. Simulations courtesy Hanli Liu, NCAR. This image video is freely available for media & nonprofit use.)

 

 

http://www2.ucar.edu/atmosnews/just-published/15335/watch-invisible-waves-rumble-through-atmosphere#gravity_waves_video