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Stray Light Correction for the Helioseismic and Magnetic Imager
A. A. Norton, T. L. Duvall, J. Schou +6
We report a point spread function (PSF) and deconvolution procedure to remove stray light from the Helioseismic and Magnetic Imager (HMI) data. Pre-launch calibration observations,…
Structure and Dynamics of the Sun's Interior Revealed by Helioseismic and Magnetic Imager
Alexander Kosovichev, Sarbani Basu, Yuto Bekki +43
High-resolution helioseismology observations with the Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) provide a unique three-dimensional view of the…
Ensemble Kalman Filter Data Assimilation Into Surface Flux Transport Model To Infer Surface Flows: An Observing System Simulation Experiment
Soumyaranjan Dash, Marc L. DeRosa, Mausumi Dikpati +4
Knowledge of the global magnetic field distribution and its evolution on the Sun's surface is crucial for modeling the coronal magnetic field, understanding solar wind dynamics, co…
The Dependence of Joy's Law and Mean Tilt as a Function of Flux Emergence Phase
Lucy W. Will, Aimee A. Norton, Jon Todd Hoeksema
Data from the Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) are analyzed from 1996 to 2023 to investigate tilt angles () of bipolar magnetic regions…
Inferring Maps of the Sun's Far-side Unsigned Magnetic Flux from Far-side Helioseismic Images using Machine Learning Techniques
Ruizhu Chen, Junwei Zhao, Shea Hess Webber +3
Accurate modeling of the Sun's coronal magnetic field and solar wind structures require inputs of the solar global magnetic field, including both the near and far sides, but the Su…
Large-Scale Spatial Cross-Calibration of Hinode/SOT-SP and SDO/HMI
David F. Fouhey, Richard E. L. Higgins, Spiro K. Antiochos +7
We investigate the cross-calibration of the Hinode/SOT-SP and SDO/HMI instrument meta-data, specifically the correspondence of the scaling and pointing information. Accurate calibr…
Improvement of the Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Inversion Code
Ana Belén Griñón-Marín, Adur Pastor Yabar, Yang Liu +2
A spectral line inversion code, Very Fast Inversion of the Stokes Vector (VFISV), has been used since May 2010 to infer the solar atmospheric parameters from the spectropolarimetri…
Fast and Accurate Emulation of the SDO/HMI Stokes Inversion with Uncertainty Quantification
Richard E. L. Higgins, David F. Fouhey, Dichang Zhang +7
The Helioseismic and Magnetic Imager (HMI) onboard NASA's Solar Dynamics Observatory (SDO) produces estimates of the photospheric magnetic field which are a critical input to many…
The Coronal Global Evolutionary Model: Using HMI Vector Magnetogram and Doppler Data to Determine Coronal Magnetic Field Evolution
J. Todd Hoeksema, William P. Abbett, David J. Bercik +10
The Coronal Global Evolutionary Model (CGEM) provides data-driven simulations of the magnetic field in the solar corona to better understand the build-up of magnetic energy that le…
On Deflection of Solar Coronal Mass Ejections by the Ambient Coronal Magnetic Field Configuration
Jingjing Wang, J. Todd Hoeksema, Siqing Liu
Solar Coronal Mass Ejections (CMEs) are sometimes deflected during their propagation. This deflection may be the consequence of interaction between a CME and a coronal hole or the…
Roles of photospheric motions and flux emergence in the major solar eruption on 2017 September 6
Rui Wang, Ying D. Liu, J. Todd Hoeksema +2
We study the magnetic field evolution in the active region (AR) 12673 that produced the largest solar flare in the past decade on 2017 September 6. Fast flux emergence is one of th…
On-Orbit Performance of the Helioseismic and Magnetic Imager Instrument onboard the Solar Dynamics Observatory
J. Todd Hoeksema, Charles S. Baldner, Rock I. Bush +2
The Helioseismic and Magnetic Imager (HMI) instrument is a major component of NASA's Solar Dynamics Observatory (SDO) spacecraft. Since beginning normal science operations on 1 May…
Flare Prediction Using Photospheric and Coronal Image Data
Eric Jonas, Monica G. Bobra, Vaishaal Shankar +2
The precise physical process that triggers solar flares is not currently understood. Here we attempt to capture the signature of this mechanism in solar image data of various wavel…
Investigating the Magnetic Imprints of Major Solar Eruptions with SDO/HMI High-Cadence Vector Magnetograms
Xudong Sun, J. Todd Hoeksema, Yang Liu +2
The solar active region photospheric magnetic field evolves rapidly during major eruptive events, suggesting appreciable feedback from the corona. Previous studies of these "magnet…
Observables Processing for the Helioseismic and Magnetic Imager Instrument on the Solar Dynamics Observatory
Sebastien Couvidat, Jesper Schou, J. Todd Hoeksema +6
NASA's Solar Dynamics Observatory (SDO) was launched 11 February 2010 with 3 instruments on board, including the Helioseismic and Magnetic Imager (HMI). Since beginning normal oper…
The Coronal Global Evolutionary Model: Using HMI Vector Magnetogram and Doppler Data to Model the Buildup of Free Magnetic Energy in the Solar Corona
George H. Fisher, William. P. Abbett, David J. Bercik +11
The most violent space weather events (eruptive solar flares and coronal mass ejections) are driven by the release of free magnetic energy stored in the solar corona. Energy can bu…
The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Magnetohydrodynamics Simulation Module for the Global Solar Corona
Keiji Hayashi, J. Todd Hoeksema, Yang Liu +3
Time-dependent three-dimensional magnetohydrodynamics (MHD) simulation modules are implemented at the Joint Science Operation Center (JSOC) of Solar Dynamics Observatory (SDO). The…
Why Is the Great Solar Active Region 12192 Flare-Rich But CME-Poor?
Xudong Sun, Monica G. Bobra, J. Todd Hoeksema +6
Solar active region (AR) 12192 of October 2014 hosts the largest sunspot group in 24 years. It is the most prolific flaring site of Cycle 24, but surprisingly produced no coronal m…
On Polar Magnetic Field Reversal and Surface Flux Transport During Solar Cycle 24
Xudong Sun, J. Todd Hoeksema, Yang Liu +1
As each solar cycle progresses, remnant magnetic flux from active regions (ARs) migrates poleward to cancel the old-cycle polar field. We describe this polarity reversal process du…
The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Overview and Performance
J. Todd Hoeksema, Yang Liu, Keiji Hayashi +9
The Helioseismic and Magnetic Imager (HMI) began near-continuous full-disk solar measurements on 1 May 2010 from the Solar Dynamics Observatory (SDO). An automated processing pipel…
The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: SHARPs -- Space-weather HMI Active Region Patches
Monica G. Bobra, Xudong Sun, J. Todd Hoeksema +5
A new data product from the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) called Space-weather HMI Active Region Patches (SHARPs) is now avail…
The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Optimization of the Spectral Line Inversion Code
R. Centeno, J. Schou, K. Hayashi +5
The Very Fast Inversion of the Stokes Vector (VFISV) is a Milne-Eddington spectral line inversion code used to determine the magnetic and thermodynamic parameters of the solar phot…
Reversals of the solar magnetic dipole in the light of observational data and simple dynamo models
V. V. Pipin, D. Moss, D. D. Sokoloff +1
Observations show that the photospheric solar magnetic dipole usually does not vanish during the reversal of the solar magnetic field, which occurs in each solar cycle. In contrast…
Hot Spine Loops and the Nature of a Late-Phase Solar Flare
Xudong Sun, J. Todd Hoeksema, Yang Liu +4
The fan-spine magnetic topology is believed to be responsible for many curious features in solar explosive events. A spine field line links distinct flux domains, but direct observ…