Determination of the time dependency (secular variation) of a planet’s magnetic field provides a window into understanding the dynamo responsible for generating its field. However, of the six Solar System planets with active dynamos, secular variation has been firmly established only for Earth. Here, we compare magnetic field observations of Jupiter from the Pioneer 10 and 11, Voyager 1 and Ulysses spacecraft (acquired 1973–1992) with a new Juno reference model (JRM09)¹. We find a consistent, systematic change in Jupiter’s field over this 45-year time span, which cannot be explained by changes in the magnetospheric field or by changing the assumed rotation rate of Jupiter. Through a simplified forward model, we find that the inferred change in the field is consistent with advection of the field by Jupiter’s zonal winds, projected down to 93–95% of Jupiter’s radius (where the electrical conductivity of the hydrogen envelope becomes sufficient to advect the field). This result demonstrates that zonal wind interactions with Jupiter’s magnetic field are important and lends independent support to atmospheric and gravitational-field determinations of the profile of Jupiter’s deep winds.

确定行星磁场的时间依赖性（长期变化）为了解负责产生其磁场的发电机提供了一个窗口。但是，在六个具有活跃动力的太阳系行星中，仅针对地球已经确定了长期变化。在这里，我们将先驱者10和11，旅行者1号和尤利西斯号航天器（1973–1992年获得）对木星的磁场观测与新的朱诺参考模型（JRM09）^{1进行比较}。我们发现在这45年的时间里，木星场发生了持续，系统的变化，这不能用磁层磁场的变化或通过改变木星的假定旋转速度来解释。通过简化的正向模型，我们发现，推测的磁场变化与木星的纬向风对流场的平流一致，投射到木星半径的93％至95％（氢包壳的电导率足以平移）场）。该结果表明纬向风与木星磁场的相互作用很重要，并为大气和重力场对木星深风廓线的确定提供了独立的支持。