Researchers statistically analyze small-scale magnetic reconnections

Credit: CC0 Public DomainDr. Xue Zhike's Yunnan Observatories of Chinese Academy of Sciences statistically examined six small-scale magnetic connections using high-resolution data from the Fuxian Solar Observatory of Yunnan Observatories. The Astrophysical Journal published the findings.Magnetic reconnection is crucial in determining the topology and distribution of magnetic fields within cosmic plasma. It also provides an efficient method for converting magnetic energy into kinetic energy. Although magnetic reconnection can be difficult to confirm and observe, it is often directly linked to solar eruptions. Many of the previous observational reports about magnetic reconnection were based on one event.The researchers reviewed the high-resolution data from the NVST between 2012 and 2020. They found six cases of magnetic reconnection that had obvious inflows or outflows.These magnetic reconnections all have large separatrix angles. The NVST and Solar Dynamics Observatory (SDO) were able to determine their morphological characteristics as well as the magnetic field configurations. A number of physical parameters were also calculated for each magnetic reconnection, including the velocity of reconnection outflows and inflows, as well as the angles between separatrices and the current sheets' widths and ratios.Researchers found that the outflow velocity (the separatrix jet velocity) and the width/length of the current sheets are positively related with the inflow speed. However, the separatrix angles does not depend on inflow velocity but is related to initial magnetic field configuration prior to magnetic reconnection.They found that in addition to the current velocity, the magnetic diffusivity and the magnetic Reynolds number are also important for determining the width of the current sheets.There are six different magnetic reconnection rates. They differ and decrease with increasing inflow velocity. Both the current sheet parameters and the kinetic parameters yield consistent results. The jet and outflow reach maximum velocity when the separatrix angle is near 90.These observations match the theoretical model and numerical simulation results. To better understand magnetic reconnection and its triggers, future research will require the observation of finer structures and precise magnetic fields.Continue reading New Vacuum Solar Telescope shows acceleration of magnetic reconnectFurther information: Z. K. Xue et. al., Observations on Magnetic Reconnection With Large Separatrix Angles And Separatrix Jets Above the Solar Surface, The Astrophysical Journal (2021). Information from Astrophysical Journal Z. K. Xue et. al., Observations on Magnetic Reconnection With Large Separatrix Angles And Separatrix Jets Above the Solar Surface. (2021). DOI: 10.3847/1538-4351/abfb71