标题： 对流中从弹道到扩散涡旋运动的交叉 显示英文标题

标题： Crossover from ballistic to diffusive vortex motion in convection

摘要： 涡旋在天体物理和地球物理中的热量和动量传输中起着独特的作用，也是地球发电机的起源。 长期以来存在一个问题，即是否可以根据涡旋的历史数据预测或理解其运动。 在这里，我们通过实验和数值模拟来展示涡旋运动和分布的一些普遍特征。 可以发现，涡旋的运动可以在布朗粒子的框架下描述，它们在比某些临界时间尺度短的时间内作弹道运动，然后作扩散运动。 传统上，在考虑涡旋运动时，常常忽略了它们的惯性，我们的结果表明，涡旋实际上具有惯性引起的记忆，使得它们的短期运动可以被预测。 扩展到天体物理和地球物理，大气和海洋中涡旋的过渡临界时间尺度在几分钟量级，在此情况下，这种惯性效应相比其他引导源往往被忽略。 然而，涡旋的时间尺度要大得多，范围从几天到一年。 这推导出一个新的概念，即不仅外部源，例如太阳风，而且内部源，即涡旋的惯性，也可以对地球磁场的短期变化做出贡献。 显示英文摘要

摘要： Vortices play an unique role in heat and momentum transports in astro- and geo-physics, and it is also the origin of the Earth's dynamo. A question existing for a long time is whether the movement of vortices can be predicted or understood based on their historical data. Here we use both the experiments and numerical simulations to demonstrate some generic features of vortex motion and distribution. It can be found that the vortex movement can be described on the framework of Brownian particles where they move ballistically for the time shorter than some critical timescales, and then move diffusively. Traditionally, the inertia of vortex has often been neglected when one accounts for their motion, our results imply that vortices actually have inertial-induced memory such that their short term movement can be predicted. Extending to astro- and geo-physics, the critical timescales of transition are in the order of minutes for vortices in atmosphere and ocean, in which this inertial effect may often be neglected compared to other steering sources. However, the timescales for vortices are considerably larger which range from days to a year. It infers the new concept that not only the external sources alone, for example the solar wind, but also the internal source, which is the vortex inertia, can contribute to the short term Earth's magnetic field variation.