Erratum to: Constraints on oceanic meridional heat transport from combined measurements of oxygen and carbon

1 Erratum to: Clim Dyn (2016) 47:3335–3357 DOI:10.1007/s00382-016-3029-3

The original article has been published online with 2 errors. The errors have been corrected as below:

• 1. The definition of pre-industrial oceanic potential oxygen (OPO_pi) given in Eq. (7) reads:

$$ {\text{OPO}}_{{{\text{pi}}}} = {\text{ O}}_{{\text{2}}}{}^{*} + {\text{1}}.{\text{1}} \times {\text{C}}_{{{\text{pi}}}}{} ^{*} $$

but should appear as:

$$ {\text{OPO}}_{{{\text{pi}}}} = {\text{ O}}_{{\text{2}}} {}^{*} + {\text{1}}.{\text{1}} \times {\text{C}}_{{{\text{pi}}}}{} ^{*} - \left( {{\text{1}}/{\text{X}}_{{{\text{N}}_{{\text{2}}} }} } \right) \times {\text{N}}_{{\text{2}}} $$

where ${\text{O}}_{2}{}^{*}$ and ${\text{C}}_{{{\text{pi}}}}{}^{*}$ are the quasi-conservative ocean tracer concentrations tracking air–sea exchanges of O₂ and pre-industrial CO₂, N₂ is the dissolved N₂ ocean concentration and ${\text{X}}_{{{\text{N}}_{{\text{2}}} }}$ is the atmospheric mole fraction of N₂ (${\text{X}}_{{{\text{N}}_{{\text{2}}} }}$ = 0.7808).

This definition of OPO_pi and the OPO_pi data shown on Fig. 1 therefore include the changes in OPO due to air–sea fluxes of O₂ and pre-industrial CO₂ but also due to the thermally driven air–sea fluxes of N₂, which are important for understanding changes in pre-industrial atmospheric potential oxygen (APO_pi). Including the N₂ contribution makes OPO_pi a mirror tracer of APO_pi across the air–sea interface, i.e. with equivalent air–sea fluxes. The data based OPO_pi to potential temperature ratio derived from Fig. 1 includes the N₂ contribution and is equal to −3.9 nmol/J. Note that without the N₂ contribution, this ratio would equal −4.4 nmol/J.

• 2. In Table 1, the isopycnal defining the base of the thermocline reads ${\sigma _\theta }$ = 24.7 and should read ${\sigma _\theta }$ = 27.4.