Jupiter's outer, equatorial atmosphere rotates at 12,517.12 meters/second, once every 9.5 hours, at a radius of 71,492 km. Geostationary orbital speeds for earth are around 3,000 meters/second, at a radius of 42,164 km. From what I understand, the gravitational acceleration in the upper atmosphere of Jupiter is around 2.4g.
Would a stationary probe (relative to the atmosphere) that maintained its altitude with something like a hot hydrogen air balloon or vacuum-filled sphere experience noticeably less gravity than 2.4g from the extremely fast rotation of Jupiter at the equator? Or to ask in another way, is there noticeably less gravity at the equator than the poles, due to the high rotation rate of the gas giant?