The Slowly Varying Corona: Findings from DEMs with the EVE MEGS-A Dataset
Abstract
We present analysis of the complete spectral dataset from the Extreme-ultraviolet (EUV) Variability Experiment (EVE) MEGS-A instrument. Using these data, we construct daily differential emission measures (DEMs) and use them to analyze the long-term variability of the global corona. We identify a discontinuity in the DEMs separating solar minimum and maximum conditions and we discuss the implications of the DEMs on the energy balance in the corona. Using the DEMs we also study the relationship between EUV and F10.7, the 10.7 cm (2.8 GHz) solar activity proxy. We compare the F10.7 predictions from the DEMs and photospheric magnetic field observations with microwave observations to constrain the source mechanisms of F10.7 and their relative contribution as a function of solar activity. Combining the DEMs with irradiance microwave observations allows for a determination of the coronal iron abundance and a measurement of the FIP effect.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2017)
- Pub Date:
- July 2017
- Bibcode:
- 2017shin.confE.157S