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Solar Origin of Compressive Alfv\ enic Spikes/Kinks as Observed by Parker Solar Probe
Author | He, Jiansen; Zhu, Xingyu; Yang, Liping; Hou, Chuanpeng; Duan, Die; Zhang, Lei; Wang, Ying; |
Keywords | Parker Data Used; Solar wind; Alfven waves; Solar atmosphere; Solar magnetic reconnection; 1534; 23; 1477; 1504 |
Abstract | The solar wind is found by the Parker Solar Probe to be abundant with Alfv\ enic velocity spikes and magnetic field kinks. Temperature enhancement is another remarkable feature associated with the Alfv\ enic spikes. How the prototype of these coincident phenomena is generated intermittently in the source region is an important and wide-ranging subject. Here we propose a new model introducing guide-field discontinuity into the interchange magnetic reconnection between open funnels and closed loops with different magnetic helicities. The modified interchange reconnection model not only can accelerate jet flows from the newly opening closed loop but also can excite and launch Alfv\ enic wave pulses along the newly reconnected and post-reconnected open flux tubes. We find that the modeling results can reproduce the following observational features: (1) Alfv\ en disturbance is pulsive in time and asymmetric in space; (2) Alfv\ enic pulse is compressive with temperature enhancement and density variation inside the pulse. We point out that three physical processes co-happening with Alfv\ en wave propagation can be responsible for the temperature enhancement: (a) convection of heated jet flow plasmas (decrease in density), (b) propagation of compressive slow-mode waves (increase in density), and (c) conduction of heat flux (weak change in density). We also suggest that the radial nonlinear evolution of the Alfv\ enic pulses should be taken into account to explain the formation of magnetic switchback geometry. |
Year of Publication | 2021 |
Journal | \apjl |
Volume | 913 |
Number of Pages | L14 |
Section | |
Date Published | may |
ISBN | |
URL | |
DOI | 10.3847/2041-8213/abf83d |