Wave Propagation in the Internetwork Chromosphere: Comparing IRIS Observations of Mg II h and k with Simulations

Friday, 19 December 2014
Bernhard Fleck, European Space Agency, Villanueva De La Can, Spain, Bart De Pontieu, Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA, United States, Jorrit Leenaarts, Stockholm University, Stockholm, Sweden, Tiago M.D. Pereira, University of Oslo, Oslo, Norway and Thomas Straus, INAF/OAC, Naples, Italy
The objective of this study is to explore the dynamics of the upper internetwork chromosphere using high-resolution spectroscopic “sit-and-stare” time series obtained with the Interface Region Imaging Spectrogragh (IRIS) in the Mg II h and k lines. The Mg II h and k lines reveal a particularly complex spatio-temporal behavior, which strongly depends on the magnetic field topology. We focus on six parameters in both the h and k line: the Doppler shift and intensity of the central reversal (h3 and k3) and the blue and red emission peaks (h2v, h2r, k2v, k2r). In an effort to better understand what physical parameters can be extracted from these lines and to put our interpretation of the observations on more solid grounds, we extend our analysis to synthetic spectra obtained from numerical simulations and compare the results to the observations.