标题： 第23活动周太阳子午速度剖面的变化通过流向活动带的流解释 显示英文标题

标题： Changes of the solar meridional velocity profile during cycle 23 explained by flows towards the activity belts

摘要： 太阳经向流是 Babcock-Leighton 太阳发电机模型中的一个重要组成部分。这种流的全球变化曾被用来解释活动周期振幅和长度的变化。最近，有报道称在观测到的经向流的勒让德分解中的 $P_2^1$ 项的振幅在周期中有所变化。这一结果通常被解释为活动周期内流速振幅的整体变化。我们使用一个基于太阳表面磁通量分布的半经验模型表明， $P_2^1$ 项的变化可以由活跃区域带的局部流入所解释。不需要整体经向流振幅的变化。 显示英文摘要

摘要： The solar meridional flow is an important ingredient in Babcock-Leighton type models of the solar dynamo. Global variations of this flow have been suggested to explain the variations in the amplitudes and lengths of the activity cycles. Recently, cycle-related variations in the amplitude of the $P_2^1$ term in the Legendre decomposition of the observed meridional flow have been reported. The result is often interpreted in terms of an overall variation in the flow amplitude during the activity cycle. Using a semi-empirical model based upon the observed distribution of magnetic flux on the solar surface, we show that the reported variations of the $P_2^1$ term can be explained by the observed localized inflows into the active region belts. No variation of the overall meridional flow amplitude is required.