8 papers · 1 filter
Oscillatory Phase and Acoustic Travel-Time Inconsistencies Measured between SDO/HMI and GONG Dopplergrams
Junwei Zhao, Ruizhu Chen, S. P. Rajaguru +1
We investigate the causes of discrepancies in meridional-circulation measurements derived from the helioseismic observations by the Helioseismic and Magnetic Imager onboard the Sol…
Long-Term Clustering Pattern of Solar Active Regions and Their Potential Connection with Magneto-Rossby Waves
Junwei Zhao, Ruizhu Chen, Aimee A Norton
Large solar active regions (ARs) tend to be long lived and spatially clustered, with repeated emergence occurring in persistent solar activity nests over extended timescales. By an…
Active-region Modulation of Subsurface Meridional Flows and Magnetic Flux Transport on the Sun
Anisha Sen, S. P. Rajaguru, Ruizhu Chen +2
Using time-distance helioseismology applied to 14-years of SDO/HMI observations spanning solar cycle 24 and rising phase of cycle 25, we present evidence that meridional flows in t…
Structural Tilting and Depth-Dependent Behavior of Equatorial Rossby Waves
Oana Vesa, Junwei Zhao, Ruizhu Chen
Over the past decade, solar equatorial Rossby waves have been unambiguously identified and are considered potential diagnostics of solar interior dynamics. We investigate their inc…
Hemispheric Magnetic Asymmetry and Cross-Equatorial Circulation Cells within the Sun's Near-Surface Shear Layer
Anisha Sen, S. P. Rajaguru, Ruizhu Chen +2
Using time-distance helioseismic measurements of meridional flow in the near-surface shear layer over a period of 14 years, starting from May 2010, we probe the depth structure and…
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,…
Characterizing the Observational Properties of the Sun's High-latitude m=1 Inertial Mode
Boyang Ding, Junwei Zhao, Ruizhu Chen +3
Low-m inertial modes have been recently discovered in the Sun's high-latitude regions. In this study, we characterize the observational properties of the m = 1 mode by analyzing ti…
Observed Dispersive Properties of the Slow Magnetoacoustic Waves Propagating in Coronal Fan Loops above Sunspots
Junwei Zhao, Tongjiang Wang, Ruizhu Chen
Recurrent and propagating intensity perturbations are frequently observed in extreme ultraviolet (EUV) channels along coronal fan loops above sunspots, and these perturbations are…