Contributions of different terms in the generalised Ohm’s law to the out-of-plane electric field along cuts through the current sheet along the x-axis through the X-point. The vertical line in each plot marks the horizontal position of the X-point, as determined by tracking the magnetic null. The solid black lines show the out-of-plane electric field (not including the advective electric field component), dashed lines the contribution of the divergence of the pressure tensor, dash-dotted lines the contribution of the convective inertia, and dotted lines the contribution from the rate of change of bulk inertia. The solid grey line represents the sum of the contributing terms.