Buizert(2014) fig 1 frames g-i attached, T reconstructed from delta-15N + model which is briefly described in the supplementary.
reconstruction has gravitational and thermal diffusion, firn densification and a bunch else. In principle this should be possible, but as the supplementary shows, it is not straightforward. I wonder if the analysis can be applied to other isotopes (they did so some on 18O)
Seasonality results make sense, but lean heavily on ocean+atmos models forced with meltwater efflux into N. Atlantic to shut down AMOC.
sidd