HAO Colloquium - Constraining the (acoustic-) wave heating in the solar chromosphere with ALMA, the Dunn Solar Telescope, and IRIS

Speaker: Momchil Molnar, NSO 

In this talk, I will present constraints on the longitudinal (compressive) and transverse (Alfvenic) wave velocity perturbations observed in the upper photosphere and chromosphere. Better knowledge of the wave energy fluxes in these different wave modes in different regions of the atmosphere are important inputs into models for wave heating of the solar atmosphere. By using observations at multiple viewing angles (distances from the disc center), the relative importance of these two components can be evaluated and the power in the local wave flux can be explored. This work is based on observations from the IRIS spacecraft (using the Mg II h & k and the Mn I 280.9 nm lines), the IBIS instrument at the Dunn Solar Telescope (using the Ca II 854.2 nm and Na D1 lines) and brightness temperatures from ALMA. We combine the observations with MHD models (RADYN and BIFROST) of the lower solar atmosphere to estimate the wave flux throughout the chromosphere based on spectral synthesis with the RH15D code. This study provides estimates of longitudinal and transverse wave power in the chromosphere, with associated constraints on the heating inputs in the middle and upper chromosphere.

Date and time: 
Wednesday, November 3, 2021 - 2:00pm to 3:00pm