  The element abundances in the solar corona and solar wind are often different
from those of the solar photosphere, typically with a relative enrichment of
elements with low first ionization potential (FIP effect). Here we study the
spatial distribution and temporal evolution of the coronal chemical composition
in an active region (AR) over about 10 days, using Hinode/EIS spectra, and we
also analyze coordinated IRIS observations of the chromospheric and transition
region emission to investigate any evidence of the footprints of the FIP effect
in the lower atmosphere. To derive the coronal abundances we use a spectral
inversion method recently developed for the MUSE investigation (Cheung et al.
2019, De Pontieu et al. 2020). We find that in the studied active region (AR
12738) the coronal FIP bias presents significant spatial variations, with its
highest values (~ 2.5-3.5) in the outflow regions at the boundary of the AR,
but typically modest temporal variability. Some moss regions and some regions
around the AR sunspot show enhanced FIP (~ 2-2.5) with respect to the AR core,
which has only a small FIP bias of ~1.5. The FIP bias appears most variable in
some of these moss regions. The IRIS observations reveal that the chromospheric
turbulence, as derived from IRIS2 inversions of the Mg II spectra, is enhanced
in the outflow regions characterized by the high FIP bias, providing
significant new constraints to both models aimed at explaining the formation of
AR outflows and models of chemical fractionation.
