The phenomena of fast magnetosonic waves propagation in the solar corona has recently been observed with SDO/AIA observatory. The underlying physical mechanism remains unclear. We proposed a idea that the fast magnetosonic waves may be excited by the impact of reconnection jet flow into the ambient coronal open fields. We carried out the numerical simulation to reproduce this scenario self-consistently. In the numerical process, coronal closed loops are driven by the shear motions in the photoshere, give rise to magnetic reconnection with open fields in the neighborhood, eject high-speed plasmoids. The ejected high-speed plasmoids finally impact into the upflow region, and thereby exciting the fast magnetosonic waves, which are similar to the observations in many characteristics.
This work is published on ApJ
Authors: Liping YANG, Lei ZHANG, Jiansen HE, Hardi PETER, Chuanyi TU, Linghua WANG, Shaohua ZHANG, and Xueshang FENG.
The group of Solar and Heliospheric Physics has published a research paper on Ann. Geophys., focusing on how to identify slow magnetosonic waves in MHD turbulence. A new criteria is proposed in this paper. The advantage of this criteria lies in its insensitiveness to the propagation angle, which is not easy to estimate in the 3D simulation data. Therefore, the method of this work can be applied to the identification and statistical analysis of the compressive waves in 3D turbulence. The authors also qualitatively describe the physical feature and temporal evolution of four events of slow mode waves as identified.
Gyro-averaged equations of particle motion for resonances with oblique whistler-mode waves were previously derived by multiple authors with inconsistent formulas. This study suggests a check on self-consistency: the energy variation resulting from momentum equations should not contain any wave magnetic components. We also show that the wave centripetal force, which was neglected in previous studies, can significantly enhance electron phase trapping. This force can also bounce low pitch angle particles out of the loss cone. 