Small scale variability in quiet sun and coronal holes
Abstract
IRIS (Interface Region Imaging Spectrograph) was launched in 2013 and revealed small-scale rapid brightening variations in large regions in the quiet sun and coronal holes. Their lifetime is smaller than a couple of minutes and the distance between them is of a granular scale. We are going to present a statistical study of their observed properties such as variability, lifetime, frequency using the images of the SJI, and velocities, and temperatures using the spectral data coming IRIS. The spectrograph reveals that most of this emission comes from the continuum and their properties reveals that most of these events result from acoustic shocks. We compare our observations with synthetic observables (using forward modeling with the RH and multi3D code) from recent numerical 3D radiative-MHD simulations using the Bifrost code (Gudiksen et al. 2011). Similar rapid brightening variability of chromospheric synthetic images has been also reproduced in our simulations with mainly unipolar field. We will describe their evolution, how they are driven and their thermodynamic properties from the simulations.
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E2020M