  Within the coronae of stars, abundances of those elements with low first
ionization potential (FIP) often differ from their photospheric values. The
coronae of the Sun and solar-type stars mostly show enhancements of low- FIP
elements (the FIP effect) while more active stars such as M-dwarfs have coronae
generally characterized by the inverse-FIP effect (I-FIP). Here we observe
patches of I-FIP effect solar plasma in AR 12673, a highly complex
beta/gamma/delta active region. We argue that the umbrae of coalescing sunspots
and more specifically strong light bridges within the umbrae, are preferential
locations for observing I-FIP effect plasma. Furthermore, the magnetic
complexity of the active region and major episodes of fast flux emergence also
lead to repetitive and intense flares. The induced evaporation of the
chromospheric plasma in flare ribbons crossing umbrae enables the observation
of four localized patches of I-FIP effect plasma in the corona of AR 12673.
These observations can be interpreted in the context of the ponderomotive force
fractionation model which predicts that plasma with I-FIP effect composition is
created by the refraction of waves coming from below the chromosphere. We
propose that the waves generating the I-FIP effect plasma in solar active
regions are generated by sub-photospheric reconnection of coalescing flux
systems. Although we only glimpse signatures of I-FIP effect fractionation
produced by this interaction in patches on the Sun, on highly active M-stars it
may be the dominant process.
