Determinations of the solar oxygen content relying on the neutral forbidden transition at 630 nm depend upon the nickel abundance , due to a Ni i blend .
Here we rederive the solar nickel abundance , using the same ab initio 3D hydrodynamic model of the solar photosphere employed in the recent revision of the abundances of C , N , O and other elements .
Using 17 weak , unblended lines of Ni i together with the most accurate atomic and observational data available we find \log \epsilon _ { Ni } = 6.17 \pm 0.02 \mathrm { ( statistical ) } \pm 0.05 \mathrm { ( % systematic ) } , a downwards shift of 0.06–0.08 dex relative to previous 1D-based abundances .
We investigate the implications of the new nickel abundance for studies of the solar oxygen abundance based on the [ O i ] 630 nm line in the quiet Sun .
Furthermore , we demonstrate that the oxygen abundance implied by the recent sunspot spectropolarimetric study of Centeno & Socas-Navarro needs to be revised downwards from \log \epsilon _ { O } = 8.86 \pm 0.07 to 8.71 \pm 0.10 .
This revision is based on the new nickel abundance , application of the best available gf -value for the 630 nm forbidden oxygen line , and a more transparent treatment of CO formation .
Determinations of the solar oxygen content relying on forbidden lines now appear to converge around \log \epsilon _ { O } = 8.7 .