Affiliation

National Solar Observatory

Main category

Natural Sciences (Physics)

Abstract

We infer the temperature stratification in the lower solar chromosphere using the Ca II spectral line observations by the SOLIS/VSM instrument. The spectral line profiles across the full solar disk were first grouped using k-means clustering algorithm into a set of representative profiles, these profiles were then inverted under NLTE assumptions to generate a database of model atmospheres. Using a database of these representative profiles and their model atmospheres allows us to infer the temperature stratification as a function of optical depth in the lower chromosphere, for the entire set of full disk observations spanning 2010-2017, within a reasonable amount of time: given that NLTE inversions are compute intensive and time consuming. Applying our fast inversion approach to the SOLIS/VSM synoptic observations from 2010-2017 we search for long term variations in the thermal stratification of the lower solar atmosphere.

Link this presentation

https://science-media.org/presentation/703