Main Objective:
Understanding the spatial correlation between Solar Abundances and F10.7 Radio Emission using JVLA during Increasing Solar Activity
Scientific Justification: Element abundance signatures have long been used as tracers of physical processes throughout astrophysics. Understanding the spatial and temporal variations in the composition of the solar corona offers an insight into how matter and energy flow from the chromosphere, where the plasma is separated according to chemical populations (i.e., fractionated), out into the heliosphere.
In a recent Nature Communications paper (Brooks et al. 2017), we demonstrated that the FIP bias derived from full-Sun spectra is highly correlated (r = 0.88) with the F10.7 cm radio flux, a solar activity proxy, during the rising phase of the solar cycle from 2010-2014. However, the correlation appears to become nonlinear at times of increased magnetic activity on the Sun (Brooks et al. 2017). As a result, in 2020, we organised a joint JVLA-EIS-IRIS observation campaign to investigate the spatial correlation between FIP bias and the different emission mechanisms of the F10.7 flux using a small and simple bipolar active region, AR 12759. The data obtained in the joint observation has been written up to form the key part of To et al. (In prep). The results show that in a small active region, FIP bias correlates well with the F10.7 free-free emission, but not the gyroresonace emission. In this follow up campaign, we would like to observe a more complex AR during increasing solar activity, further verifying and understand this breakdown in correlation.
The JVLA observation will be supported by simultaneous observations with the Hinode/EUV Imaging Spectrometer (EIS) and the Interface Region Imaging Spectrograph (IRIS). The combination of these three telescopes will ensure coverage in radio (VLA), UV (IRIS) and EUV (Hinode/EIS) emission throughout the solar atmosphere from the chromosphere to the corona. Results of the study will
1. improve our understanding of the underlying causes of the non-linearity of the FIP bias - F10.7 solar index correlation found by Brooks et al. (2017) and To et al. (In prep).
2. Provide constraints on the amplitude of composition variability related to solar cycle amplitude. This in turn will inform stellar astronomers about the amplitude of variability in stellar coronal composition and its dependence on magnetic activity.
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