Plasma Upflows Induced by Magnetic Reconnection Above an Eruptive Flux Rope
arXiv:2106.16137 · doi:10.1007/s11207-021-01849-7
Abstract
One of the major discoveries of Hinode's Extreme-ultraviolet Imaging Spectrometer (EIS) is the presence of upflows at the edges of active regions. As active regions are magnetically connected to the large-scale field of the corona, these upflows are a likely contributor to the global mass cycle in the corona. Here we examine the driving mechanism(s) of the very strong upflows with velocities in excess of 70 km/s, known as blue-wing asymmetries, observed during the eruption of a flux rope in AR 10977 (eruptive flare SOL2007-12-07T04:50). We use Hinode/EIS spectroscopic observations combined with magnetic-field modeling to investigate the possible link between the magnetic topology of the active region and the strong upflows. A Potential Field Source Surface (PFSS) extrapolation of the large-scale field shows a quadrupolar configuration with a separator lying above the flux rope. Field lines formed by induced reconnection along the separator before and during the flux-rope eruption are spatially linked to the strongest blue-wing asymmetries in the upflow regions. The flows are driven by the pressure gradient created when the dense and hot arcade loops of the active region reconnect with the extended and tenuous loops overlying it. In view of the fact that separator reconnection is a specific form of the more general quasi-separatrix (QSL) reconnection, we conclude that the mechanism driving the strongest upflows is, in fact, the same as the one driving the persistent upflows of approx. 10 - 20 km/s observed in all active regions.
References in corpus (28)
- A Model for Solar Coronal Mass Ejections
- The Interface Region Imaging Spectrograph (IRIS)
- Observing the Roots of Solar Coronal Heating - in the Chromosphere
- Multi-scale Gaussian normalization for solar image processing
- EUV emission lines and diagnostics observed with Hinode/EIS
- Photospheric flux cancellation and associated flux rope formation and eruption
- High precision density measurements in the solar corona: I. Analysis methods and results for Fe XII and Fe XIII
- Full-Sun observations for identifying the source of the slow solar wind
- Flows and Non-thermal Velocities in Solar Active Regions Observed with the Extreme-ultraviolet Imaging Spectrometer on Hinode: A Tracer of Active Region Sources of Heliospheric Magnetic Fields?
- Magnetic Reconnection along Quasi-Separatrix Layers as a Driver of Ubiquitous Active Region Outflows
- Two components of the coronal emission revealed by EUV spectroscopic observations
- Asymmetries of solar coronal extreme ultraviolet emission lines
- The Spectroscopic Signature of Quasi-periodic Upflows in Active Region Timeseries
- Multiple Component Outflows in an Active Region Observed with the EUV Imaging Spectrometer on Hinode
- Modelling of EIS spectrum drift from instrumental temperatures
- Velocity measurements for a solar active region fan loop from Hinode/EIS observations
- Measurements of Non-Thermal Line Widths in Solar Active Regions
- On The Doppler Velocity of Emission Line Profiles Formed in the "Coronal Contraflow" that is the Chromosphere-Corona Mass Cycle
- Upflows in the upper solar atmosphere
- The coronal source of extreme-ultraviolet line profile asymmetries in solar active region outflows
- The source of the major solar energetic particle events from super active region 11944
- Flows at the Edge of an Active Region: Observation and Interpretation
- Parallel Evolution of Quasi-separatrix Layers and Active Region Upflows
- The 3D geometry of active region upflows deduced from their limb-to-limb evolution
- The active region source of a type III radio storm observed by Parker Solar Probe during Encounter 2
- Apparent and Intrinsic Evolution of Active Region Upflows
- IRIS observations of the low-atmosphere counterparts of active region outflows
- Evolution of active region outflows throughout an active region lifetime