Through mimicking observations in high-latitude areas, we find that the foreshortening affects the time-distance measured mean travel-times, but is not accountable for the center-to-limb effect in travel-time differences.
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.
Large-scale inflows form around emerging solar active regions in the near-surface layer and alter the global meridional flow patterns.
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.
Multiple-wavelength high-resolution observations reveal running penumbral waves in the middle photosphere, with an apparent horizontal speed of up to 51 km/s.
A newly discovered, fast-moving wave propagates outward along sunspots’ radial direction and may provide new diagnostics of the sunspot subsurface structure.
Ring-diagram analysis reveals that the convective flow speed inside the Sun is consistent with most numerical simulations of global convection.
What could be common between solar atmosphere and information exchange in communicating systems? Well, this is all about how information is transferred from point A to point B. This work represents a proof-of-concept application of methods of mutual information (MI) to helioseismology.
The mean size of supergranulation has been found to vary over time with a period of 3-5 days. We have used full-disk Doppler images from the Helioseismic Magnetic Imager (HMI) to verify that these fluctuations are solar in origin.
Flow system in an average supergranule is compared to the moat flow around axisymmetric sunspots. Both phenomena are very similar, only the outflow in the moat is distorted due to the proper motion of the sunspot with respect to the local frame of rest and moat is a purely downflow region.