标题： 2010年至2024年的太阳表面磁场模拟及第24活动周南方异常极向通量传输 显示英文标题

标题： Solar Surface Magnetic Field Simulation from 2010 to 2024 and Anomalous Southern Poleward Flux Transport in Cycle 24

摘要： 太阳表面磁场对于模拟日冕磁场、研究太阳发电机效应以及预测太阳活动周强度具有根本性意义。 我们使用包含同化观测活动区（ARs）作为源的表面磁通输运模型，从2010年到2024年进行了连续的表面磁场模拟，覆盖了第24和第25个太阳活动周。 该模拟很好地再现了轴向偶极强度的演化、极向场反转时间以及与SDO/HMI观测一致的磁蝴蝶图。 值得注意的是，这些结果是在未包含径向扩散或经向环流速度周期性变化的情况下获得的，这表明它们的影响有限。 通常在整个活动周内，随后极性的向极运动占主导地位，但在第24活动周的南半球，它们仅限于2011年至2016年的短暂时期。 这种异常模式源于间歇性的活动区浮现，其中约46%的总无符号磁通量来自卡林顿旋转2141-2160期间（2013年9月至2015年2月）浮现的活动区。 这些活动区在卡林顿经度200-260度显示出强烈的活跃经度，而在80-100度则较弱。 在2016年后，领先极性通量的向极迁移变得占主导地位，尽管大多数活动区遵循乔伊定律和黑尔定律。 这种反转可能是由于活动区浮现之间的长时间间隔，这使得领先极性通量能够在随后的活动区抵消之前分布在一个较宽的纬度范围内。 这些发现强调了活动区浮现的时间间隔在驱动通量传输模式中的重要性。 显示英文摘要

摘要： The solar surface magnetic field is fundamental for modeling the coronal magnetic field, studying the solar dynamo, and predicting solar cycle strength. We perform a continuous simulation of the surface magnetic field from 2010 to 2024, covering solar cycle 24 and the ongoing cycle 25, using the surface flux transport model with assimilated observed active regions (ARs) as the source. The simulation reproduces the evolution of the axial dipole strength, polar field reversal timing, and magnetic butterfly diagram in good agreement with SDO/HMI observations. Notably, these results are achieved without incorporating radial diffusion or cyclic variations in meridional flow speed, suggesting their limited impact. Poleward surges of the following polarity typically dominate throughout the cycle, but in the southern hemisphere during cycle 24, they are limited to a short period from 2011 to 2016. This anomalous pattern arises from intermittent AR emergence, with about 46% of total unsigned flux contributed by ARs emerging during Carrington Rotations 2141-2160 (September 2013 - February 2015). These ARs show a strong active longitude at Carrington longitudes 200-260 degree and a weaker one at 80-100 degree. After 2016, poleward migrations of leading-polarity flux become dominant, despite most ARs following Joy's and Hale's laws. This reversal is likely due to prolonged intervals between AR emergences, which allow leading-polarity flux to distribute across a broad latitude range before cancellation by subsequent ARs. These findings highlight the importance of the temporal interval of AR emergence in driving the flux transport pattern.