Akatsuki Study Finds Thermal Tides Drive Venus Clouds Around Planet in 4 Days
Updated
Updated · spacedaily.com · Jul 26
Akatsuki Study Finds Thermal Tides Drive Venus Clouds Around Planet in 4 Days
1 articles · Updated · spacedaily.com · Jul 26
Summary
Akatsuki data analyzed by Takeshi Horinouchi and colleagues showed thermal tides transport angular momentum toward low latitudes, helping sustain Venus’s fastest westward winds near the equator.
At 65 to 70 kilometers up, cloud tops circle Venus in about 4 Earth days at nearly 360 kilometers per hour—about 60 times faster than the solid planet’s 243-day retrograde rotation.
The study says super-rotation is not driven by one mechanism alone: slower north-south and vertical circulation can weaken equatorial flow, while other waves and turbulence shape middle and high latitudes.
Surface and atmosphere still interact. Akatsuki observed a roughly 10,000-kilometer stationary bow-shaped feature, interpreted as a mountain-generated gravity wave rising from Aphrodite Terra into the cloud deck.
The report distinguishes four Venus clocks: a 243-day sidereal rotation, a 224.7-day year, a 116.75-day solar day, and the 4-day atmospheric circuit of the upper clouds.