The real reason Jupiter has cloudy zones and clear belts

PALS 2021/22

Speaker: T. Dowling, Ph.D.

Abstract: Jupiter’s famous banded structure consists of bright, cloudy zones and darker, clear belts. One of the most widespread misconceptions in planetary science is that the cloudy zones Indicate upwelling and the clear belts indicate downwelling. The real mechanism is much simpler and does not involve any vertical motions at all. The key is that the tropopause is flat (like the ocean surface is ‘flat’) and anticyclonic zones are cool simply so they fit under the tropopause. Likewise, cyclonic belts are warm to fill up the space and keep the tropopause flat. These come with simple emoticons: a zone is |*( ( ( and a belt is | ) ) ). WE will connect how these emoticons explain the main aspects of the hypsometric equation and the thermal-wind equation of meteorology ---intuitively and without any equations. And, we will get trained to see clouds without any “up arrow” attached to them, fighting fire with fire by labeling clouds that are clearly not from upwelling with fallacious “up arrows”. Jupiter’s zones and belts turn out to be easily visible evidence that the planet has deeply rooted jet streams.