On the fine structure of the quiet solar \Ca II K atmosphere

Abstract

We investigate the morphological, dynamical, and evolutionary properties of the internetwork and network fine structure of the quiet sun at disk centre. The analysis is based on a $\sim$6 h time sequence of narrow-band filtergrams centred on the inner-wing \Ca II K${}_{2v}$ reversal at 393.3 nm. The results for the internetwork are related to predictions derived from numerical simulations of the quiet sun. The average evolutionary time scale of the internetwork in our observations is 52 sec. Internetwork grains show a tendency to appear on a mesh-like pattern with a mean cell size of $\sim$4-5 arcsec. Based on this size and the spatial organisation of the mesh we speculate that this pattern is related to the existence of photospheric downdrafts as predicted by convection simulations. The image segmentation shows that typical sizes of both network and internetwork grains are in the order of 1.6 arcs.

8 pages, 9 figures

References in corpus (1)

• DOT tomography of the solar atmosphere. IV. Magnetic patches in internetwork areas

Cited by in corpus (9)

• Dynamics of the Solar Magnetic Network. II. Heating the Magnetized Chromosphere
• Hinode Observations of Magnetic Elements in Internetwork Areas
• The solar chromosphere at high resolution with IBIS. II. Acoustic shocks in the quiet internetwork and the role of magnetic fields
• The signature of chromospheric heating in Ca II H spectra
• Inter-network regions of the Sun at millimetre wavelengths
• MHD wave propagation from the sub-photosphere to the corona in an arcade-shaped magnetic field with a null point
• DOT Tomography of the Solar Atmosphere VII. Chromospheric Response to Acoustic Events
• Characterization of chromospheric activity based on Sun-as-a-star spectral and disk-resolved activity indices
• Small-scale structure and dynamics of the lower solar atmosphere