Presentation on theme: "Back Reaction on the Photospheric Magnetic field in Solar Eruptions Dandan Ye."— Presentation transcript:
Back Reaction on the Photospheric Magnetic field in Solar Eruptions Dandan Ye
Contents Paper review: 2005 J.J. Sudol and J.W. Harvey ‘Longitudinal magnetic field changes accompanying solar flares’ My work about flare-related magnetic field evolutions to the X1.8 flare on 2012.10.23
Paper review Background: Re-examined the basic assumptions of flare theories: the photospheric magnetic field does not change significantly during flares Data:15 X-class solar flares Global Oscillation Network Group (GONG) magnetograms
Paper review Discussion: Abrupt, significant, and permanent changes of the photospheric longitudinal magnetic field are ubiquitous features of X-class flares. Reasons: unclear (like flows compress the field; parts of the field shift horizontally; flux submerges out of sight…..)
Paper review Many of the field changes with penumbrae and the recent observations show that penumbrae weaken during flares Penumbral magnetic field more vertical So, the field lines are pulled or relax upward by the erupting flare.
My work AR 11598 (close to the west limb) Line-of sight component of magnetic field change Vector of magnetic field change Intensity Data
My work Data: Helioseismic and Magnetic Imager(HMI) data on board the SDO LOS: Magnetogram with a spatial resolution of ~1'' and a cadence of 45 seconds Vector: Vector magnetic field with a spatial resolution of ~1'' and a cadence of 12 min. Intensity: Continuum data with a cadence of 45 seconds
My work Summary: 1. Obviously the X1.8 flare produces abrupt and significant magnetic field structure change in intensity, vector field and LOS. 2. For this X1.8 flare, the diskward flux would decrease and the limbward flux would increase.
3. Prove the speculation in Wang & Liu (2010): Field lines changing to more vertical state when the central region pressure is released after flares. 4. Prove the speculation in Sudol & Harvey (2005).