Dynamics of the photosphere along the solar cycle from SDO/HMI
arXiv:1611.02152 · doi:10.1051/0004-6361/201629274
Abstract
As the global magnetic field of the Sun has an activity cycle, one expects to observe some variation of the dynamical properties of the flows visible in the photosphere. We investigate the flow field during the solar cycle by analysing SDO/HMI observations of continuum intensity, Doppler velocity and longitudinal magnetic field. We first picked data at disk center during 6 years along the solar cycle with a 48-hour time step in order to study the overall evolution of the continuum intensity and magnetic field. Then we focused on thirty 6-hour sequences of quiet regions without any remnant of magnetic activity separated by 6 months, in summer and winter, when disk center latitude B0 is close to zero. The horizontal velocity was derived from the local correlation tracking technique over a field of view of 216.4Mm x 216.4Mm located at disk center. Our measurements at disk center show the stability of the flow properties between meso- and supergranular scales along the solar cycle. The network magnetic field, produced locally at disk center independently from large scale dynamo, together with continuum contrast, vertical and horizontal flows, seem to remain constant during the solar cycle.
arXiv comment7 pages, 14 figures
References in corpus (8)
- The Solar Internetwork. I. Contribution to the Network Magnetic Flux
- On the Formation Height of the SDO/HMI Fe 6173 Doppler Signal
- 3D view of transient horizontal magnetic fields in the photosphere
- Local helioseismology and correlation tracking analysis of surface structures in realistic simulations of solar convection
- Point spread function of SDO/HMI and the effects of stray light correction on the apparent properties of solar surface phenomena
- Reconstruction of spectral solar irradiance since 1700 from simulated magnetograms
- Diffusion of magnetic elements in a supergranular cell
- Long-term trends of magnetic bright points: I. Number of MBPs at disc centre
Cited by in corpus (3)
- High-Cadence Imaging and Imaging Spectroscopy at the GREGOR Solar Telescope - A Collaborative Research Environment for High-Resolution Solar Physics
- Dynamics of Trees of Fragmenting Granules in the Quiet Sun: Hinode/SOT Observations Compared to Numerical Simulation
- A High-resolution, Inversion-Based Synoptic Study of Solar Granulation