Gurnett D A, Persoon A M, Kurth W S, Groene J B, Averkamp T F, Dougherty M K, Southwood D J
Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA.
Science. 2007 Apr 20;316(5823):442-5. doi: 10.1126/science.1138562. Epub 2007 Mar 22.
We show that the plasma and magnetic fields in the inner region of Saturn's plasma disk rotate in synchronism with the time-variable modulation period of Saturn's kilometric radio emission. This relation suggests that the radio modulation has its origins in the inner region of the plasma disk, most likely from a centrifugally driven convective instability and an associated plasma outflow that slowly slips in phase relative to Saturn's internal rotation. The slippage rate is determined by the electrodynamic coupling of the plasma disk to Saturn and by the drag force exerted by its interaction with the Enceladus neutral gas torus.
我们表明，土星等离子体盘内部区域的等离子体和磁场与土星千米波射电辐射的随时间变化的调制周期同步旋转。这种关系表明，射电调制起源于等离子体盘的内部区域，很可能源于离心驱动的对流不稳定性以及相关的等离子体流出，该流出相对于土星的内部旋转在相位上缓慢滑移。滑移率由等离子体盘与土星的电动力耦合以及它与土卫二中性气体环相互作用所施加的拖曳力决定。
