From the Great, great and great physics blog Starts With a Bang a story about a monster storm on Titan“For most of the history of our species we were helpless to understand how nature works. We took every storm, drought, illness and comet personally. We created myths and spirits in an attempt to explain the patterns of nature.” -Ann Druyan
Here on Earth, we are well aware of how devastating storms can be. From hurricanes to flash floods, an unpredictable change in weather can turn a serene setting into a catastrophe in no time at all. The clouds that fill the skies can often portend what type of weather is coming, and to me, the most impressive and fearsome of all is the rare and remarkable supercell.
Image credit: Sean Heavey / Barcroft Media, from Glasgow, Montana.
The least common and most severe type of thunderstorm, supercells form when a warm, moist layer of air (typically found above a cold layer, since heat rises) slides below an even higher-elevation cold layer. The wind shear from this motion causes vorticity, or a spinning motion, of the air in the warm layer. As the warm air tries to rise through the cold layer, the rotating vortex becomes vertical, and creates a mesocyclone, which can lead to tornadoes in the most catastrophic of cases.
Image credits: Vanessa Ezekowitz, retrieved from the wikipedia page for supercell.
Even in cases where tornadoes do not form, the supercell storm provides a spectacular deluge and incredible wind speeds.
Under the most extreme circumstances, many tornadoes erupt and the storm — although usually brief — can literally destroy an entire town, as was the case a year ago in Joplin, MO. As seen from space, only the flat top of the supercell was visible, blinding us to the destruction that was occurring underneath.
Image credit: NASA / GOES-13 satellite, of the 2011 Joplin, MO supercell.
No comments:
Post a Comment