Solar activity is usually caused by the evolution of solar magnetic fields. Magnetic field parameters derived from photospheric vector magnetograms of solar active regions have been used to analyze and forecast eruptive events such as solar flares and coronal mass ejections. Unfortunately, the most recent solar cycle 24 was relatively weak with few large flares, though it is the only solar cycle in which consistent time-sequence vector magnetograms have been available through the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) since its launch in 2010. In this paper, we look into another major instrument, namely the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) from 1996 to 2010. The data archive of SOHO/MDI covers more active solar cycle 23 with many large flares. However, SOHO/MDI data only has line-of-sight (LOS) magnetograms. We propose a new deep learning method, named MagNet, to learn from combined LOS magnetograms, Bx and By taken by SDO/HMI along with H-alpha observations collected by the Big Bear Solar Observatory (BBSO), and to generate vector components Bx' and By', which would form vector magnetograms with observed LOS data. In this way, we can expand the availability of vector magnetograms to the period from 1996 to present. Experimental results demonstrate the good performance of the proposed method. To our knowledge, this is the first time that deep learning has been used to generate photospheric vector magnetograms of solar active regions for SOHO/MDI using SDO/HMI and H-alpha data.

翻译：太阳活动通常由太阳磁场的演化而产生。自2010年太阳动态观测台(SDO)启动以来,从太阳活跃地区的光球矢量磁图中得出的磁场参数被用于分析和预测太阳耀斑和日冕物质抛射等爆发事件。不幸的是,最近太阳周期24相对弱,但很少有大耀斑,尽管这是唯一一个太阳周期,其中通过太阳地震和磁成像仪(HMI)获得连续时间序列矢量磁图的连续时间序列。我们建议采用一个新的深层次学习方法,名为MagNet,从太阳动态观测台(SDO/HPL)的混合磁盘、多普勒图像仪(MDI)中,从1996年至2010年太阳和日光层观测台观测台(SDO/HPI)的爆发事件爆发事件。SHO/MDI的数据档案中,通过SOHDO/磁性能数据,通过SO-OA的当前数据,我们用SO-矢量数据,从SO-O-O-tors的当前数据,我们用SO-tormalmal 和BI-O-tors的当前数据,我们用SO-I-I-I-O-O-O-I-Ormmmmmal 数据,我们用SO-I-I-SO-SO-SO-S-S-I 数据生成的当前数据,从SO-SO-O-O-I-I 数据生成的当前数据生成的当前数据,从SODO-I-I-ODO-O-O-O-O-ODO-O-O-O-O-O-O-O-O-O-O-O-O-I-I-I-I-I-I-I-O-O-O-O-O-I-I-I-I-I-O-I-I-ILODOL-O-ODOL-I-I-O-I-I-I-I-I-I-I-I-I-I-O-O-O-O-I-O-I-I-I-I-I-I-I-I-I-I-I-I-I-