143. The New HMI 96-Minute Vector Magnetograms
New HMI 96-minute vector magnetograms are now available. Deep averaging reduces noise and enhances long-lived magnetic structures.
Tag Archives: vector magnetogram
124. On Solar surface Electric field Estimation with 3 Poisson solvers (SEE3Po) for driving time-dependent MHD simulations of solar active regions
An algorithm, which is to calculate the electric field in order to retrieve the time variations of solar surface magnetic field observed by HMI, was recently developed.
120. Magnetic Fields and the Supply of Low-Frequency Acoustic Waves to the Solar Chromosphere
Through analyzing simultaneous HMI’s visible-light observations and AIA’s ultraviolet observations, the authors show that a significant amount of acoustic waves with frequencies lower than the theoretical cutoff frequency can channel up along less inclined magnetic field from the photosphere to the chromosphere.
106. The vector magnetic field of the Sun-as-a-star during activity cycle 24
HMI-observed vector magnetic-field maps were lowered to a resolution of lmax=5, so that a comparison between solar and stellar magnetic field is possible.
99. A Comparative Study between A Failed and A Successful Eruption Initiated from the Same Polarity Inversion Line in AR 11387
Two flares occurred in a same active region above a same polarity inversion line, but one had a failed CME eruption but another one had a successful CME eruption. This study explored why that was the case.
97. Successive X-class Flares and Coronal Mass Ejections Driven by Shearing Motion and Sunspot Rotation in Active Region NOAA 12673
Shearing motions and sunspot rotations found in NOAA AR 12673 are believed to lead the free energy buildup and flux rope formation, which are responsible for the two successive X-class flares.
92. Photospheric Magnetic Properties of Active Regions: Br or Blos?
The majority of flare forecasting methods rely on observations of magnetic field on the Sun’s surface, but which observable, Br or Blos, is a better predictor? Through comparing a few magnetic properties derived from both observables, this nugget gives some suggestion.
87. Magnetic Reconnection at the Earliest Stage of Solar Flux Emergence
The early phase of a flux emergence was observed by IRIS, and spectra of the accompanying UV bursts are analyzed. Many bursts appear to be associated with the magnetic flux cancellation, and almost all of them are located in regions with large squashing factors.
85. A Statistical Comparison between Photospheric Vector Magnetograms Obtained by SDO/HMI and Hinode/SP
Vector magnetic fields, obtained separately from the HMI and from the Stokes parameters of Hinode, are compared for a sunspot umbra, penumbra, and plages in a selected active region.
79. Homologous Circular-Ribbon Flares Driven by Twisted Flux Emergence
Two homologous circular-ribbon flares associated with two filament eruptions were observed and analyzed. The emergence of magnetic flux ropes helped to inject free energy into the region and drive the magnetic reconnection above it.