Microwave Perspective on Magnetic Breakout Eruption

Microwave maps may provide critical information on the flux rope interaction and breakout eruption if their polarization is measured with high precision. We demonstrate this diagnostic capability using 17 GHz from Nobeyama Radioheliograph (NoRH) of a circular ribbon flare SOL2014-12-17T04:51. The EUV images SDO/AIA coronal magnetic field extrapolated HMI magnetogram are also used to support interpretation microwave data. most obvious evidence for comes sign change over AR at heliographic coordinates S20E09, indicating overlying fields closed fan structure spine-like structure. Another important piece spatial temporal variations quasi-periodic pulsations (QPP) detected GHz. QPP was more in one loop leg before later moved spine region after flare. This indicates that oscillatory power transferred an interacting outer spine, along which reconnection launches torsional Alfvén waves, good agreement MHD model predictions eruption. In practical viewpoint, these two diagnostics work because observations free saturation even strong flaring regions.