Helen Pillar‘s paper on Impacts of Atmospheric Reanalysis Uncertainty on Atlantic Overturning Estimates at 25°N has been published in the Journal of Climate and is freely available.
In this study, Helen quantifies the impact of uncertainty in surface fluxes of buoyancy and momentum across different reanalysis products on the modelled Atlantic meridional overturning at 25°N between 19940-2011. Uncertainty in overturning induced by prior air–sea flux uncertainty can exceed 4 Sv within 15 years, at times exceeding the amplitude of the ensemble-mean overturning anomaly. A key result is that, on average, uncertainty in the overturning at 25°N is dominated by uncertainty in the zonal wind at lags of up to 6.5 yr and by uncertainty in surface heat fluxes thereafter, with winter heat flux uncertainty over the Labrador Sea appearing to play a critically important role.