Relationship between FIP bias and Si/S intensity ratio. The ratio of coronal to photospheric abundance (FIP bias), measured by Hinode/EIS, as a function of the Si X 258.375 Å/S X 264.233 Å intensity ratio, for a sample of 30 upflow regions observed in NOAA AR 10798 in December, 2007. These upflows show high speed asymmetric components in the blue (short wavelength) wing of the line profiles. The red dots show the results for the total emission from these profiles, and the blue dots show the results for the asymmetric component only. The magenta line shows the best-fitting linear relationship to the combined sample.