Macro-microturbulence in the solar photosphere

TL;DR

This study investigates the anisotropic velocity distribution of micro- and macroturbulence in the solar photosphere using spectral line analysis, revealing decreasing velocities with height and directional differences.

Contribution

It provides detailed measurements of micro- and macroturbulent velocities at various heights, highlighting anisotropy in the solar photosphere's turbulent motions.

Findings

Radial microturbulent velocity decreases from 1.0 to 0.3 km/s with height.

Tangential microturbulent velocity decreases from 1.7 to 1.3 km/s.

Velocities are anisotropic, with different radial and tangential components.

Abstract

The velocity distribution of the large and small-scale motion in solar photosphere has been obtained by crossing method based on fitting the observed and calculated equivalent widths as well as the central depths of the spectral lines at the center of the and the limb of the solar disk. We used about 200 Fe I lines. According to our results the motions in photosphere are anisotropic. The radial component of microturbulent velocity decreases from 1.0 to 0.3 km/s and the tangential one from 1.7 to 1.3 km/c at the photosphere heights from 200 to 500 km (log tau_5 = -1.4 and -3.5). At the same heights the radial component of the macroturbulent velocity decreases from 1.8 to 1.2 km/s and the tangential one from 2.3 to 0.8 km/s.