Relationship between Point-like Photospheric Downflows and Convective Collapse Events Seen in Hinode/SOT
Abstract
The formation of small-scale strong magnetic features in the quiet Sun was studied for a long time. It is likely that magnetic field on the solar surface is collected in the intergranular lanes by the horizontal flows in granules, and then a convective instability (collapse), which leads to downflow in the flux tube and a reduction of the internal gas pressure, intensifies them to kG levels. However, a static equilibrium with such a strong field would not be realized and the open question remained is the evolution including the possible rebounding upflow and the associated chromospheric responses, which may show up as shocks and subsequent heating. Using high-resolution time series of Hinode/SOT filter images in Na D1 line and Ca II H band at the quiet Sun disk center, we were able to identify many point-like downflows in the photosphere and corresponding chromospheric bright points, which are not always associated with magnetic field intensifications. For each event, we determined the duration, photospheric vertical flow velocities, line-of-sight field strength increase and the signature of chromospheric brightening. We present the implications of point-like downflows on the photospheric and chromospheric dynamical processes.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH43E3384S
- Keywords:
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- 7524 Magnetic fields;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7529 Photosphere;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7594 Instruments and techniques;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7924 Forecasting;
- SPACE WEATHER