The Juno mission observed that both poles of Jupiter have polar cyclones that are surrounded by a ring of circumpolar cyclones (CPCs). The north pole holds eight CPCs and the south pole possesses five, with both circumpolar rings positioned along latitude ~84° N/S. Here we explain the location, stability and number of the Jovian CPCs by establishing the primary forces that act on them, which develop because of vorticity gradients in the background of a cyclone. In the meridional direction, the background vorticity varies owing to the planetary sphericity and the presence of the polar cyclone. In the zonal direction, the vorticity varies by the presence of adjacent cyclones in the ring. Our analysis successfully predicts the latitude and number of circumpolar cyclones for both poles, according to the size and spin of the respective polar cyclone. Moreover, the analysis successfully predicts that Jupiter can hold circumpolar cyclones, whereas Saturn currently cannot. The match between the theory and observations implies that vortices in the polar regions of the giant planets are largely governed by barotropic dynamics, and that the movement of other vortices at high latitudes is also driven by interaction with the background vorticity.

朱诺号任务观察到木星的两极都有极地气旋，被一圈环极气旋（CPC）包围。北极拥有 8 个 CPC，南极拥有 5 个，两个极环都位于纬度 ~84° N/S。在这里，我们通过确定作用于木星 CPC 的主要力来解释木星 CPC 的位置、稳定性和数量，这些主要力是由于旋风背景下的涡度梯度而发展的。在子午方向，背景涡度因行星球形度和极地气旋的存在而变化。在纬向方向，涡量因环中相邻气旋的存在而变化。我们的分析根据各自极地气旋的大小和自旋成功地预测了两极环极气旋的纬度和数量。此外，分析成功地预测木星可以持有环极气旋，而土星目前不能。理论与观测的吻合表明，巨行星极地涡旋主要受正压动力学控制，其他高纬度涡旋的运动也受与背景涡度相互作用的驱动。