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Why does Venus’s upper atmosphere rotate much faster than the planet itself?

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Venus
Venus Venus photographed in ultraviolet light by the Pioneer Venus Orbiter (Pioneer 12) spacecraft, February 26, 1979. Although Venus's cloud cover is nearly featureless in visible light, ultraviolet imaging reveals distinctive structure and pattern, including global-scale V-shaped bands that open toward the west (left). Added color in the image emulates Venus's yellow-white appearance to the eye.

The phenomenon where the upper atmosphere of Venus rotates significantly faster than the planet itself is known as "superrotation." While the planet takes approximately 243 Earth days to complete a single rotation on its axis, the cloud features in its upper atmosphere circle the planet in only about four days.12

Regarding the cause of this motion, it is important to clarify that there is no definitive scientific consensus. While some aspects of the westward flow at the cloud tops can be attributed to thermal tidal motions induced by solar heating, the fundamental mechanism driving this superrotation remains an intriguing mystery in planetary science. Speculation suggests that these solar-induced thermal tides play a role, but the exact process that sustains such high atmospheric velocities—reaching approximately 100 metres per second—is not yet fully understood.21