Tag Archives: active regions

84. Abrupt and Permanent Changes of the Photospheric Magnetic Field During 75 flares observed with HMI

Contributed by Sebastián Castellanos Durán. Posted on January 16, 2018

Magnetic field changes associated with solar flares, observed by the SDO/HMI, are surveyed, and permanent changes of magnetic field are found in the majority of flare events. Properties of the magnetic field changes are further investigated.

62. Tracing p-Mode Waves from the Photosphere to the Corona in Active Regions

Contributed by Junwei Zhao. Posted on October 30, 2016

Through analyzing a suite of space- and ground-based observations, the authors report that above sunspots, helioseismic waves of different frequencies are able to channel up through the chromosphere and transition region into corona. General pictures of how the waves make into corona are also shown.

60. SDO/HMI Survey of Emerging Active Regions for Helioseismology and Other Solar Physics Applications (SDO/HEAR)

Contributed by Hannah Schunker. Posted on September 28, 2016

We have generated a dataset of emerging active regions (EARs) observed by SDO/HMI that is specifically suitable for helioseismic analysis. Using this dataset we show that, on average the bipoles have a symmetric the east-west velocity relative to differential rotation.

51. Magnetic Field Reconstruction Based on Sunspot Oscillations

Contributed by Johannes Löhner-Böttcher. Posted on April 25, 2016

We observed magnetoacoustic waves propagating along the magnetic field lines of a sunspot. Based on the wave periods and atmospheric characteristics, we reconstructed the magnetic field topology of the sunspot.

30. Surface and Coronal Field Signatures of Implosions in Two Homologous Solar Flares

Contributed by Chang Liu. Posted on October 27, 2014

By synthesizing the results of photospheric field change indicated by HMI observations and coronal field variation suggested by the NLFFF modeling, we study the flare-related 3D magnetic restructuring and find it consistent with the coronal implosion scenario in the low solar atmosphere.