Heat and carbon changes in the ocean as a transient response and tool for decomposing heat uptake

<p><span>Whilst anthropogenic activities are significantly altering the climate, both warming the atmosphere and increasing CO2, the ocean is</span></p><p><span>significantly ameliorating both effects. This effect is so important that the transient climate response to carbon emissions (TCRE), can be</span></p><p><span>formulated primarily in terms of the ocean. We show that in direct analogy to the TCRE, Anthropogenic Carbon (Canth) and temperature increases in the ocean are</span></p><p><span>linearly related, both globally and integrated over a range of scales. These ocean responses are typically of order 0.02K/mumol/kg,</span></p><p><span>(equivalently ~80MJ/mol). This linear relation allows for direct translation between temperature and carbon inventory increases. Furthermore,</span></p><p><span>we are far better able to decompose DIC changes into Canth increases and that of other carbon pools, than we are decomposing heat</span></p><p><span>inventory changes into added and redistributed heat. By separating total DIC change into Canth and that of other carbon pools, we can therefore remove the effect</span></p><p><span>of the transient response relationship between heat and carbon. This allows the production of estimates of added and redistributed heat in the</span></p><p><span>ocean from remaining DIC changes. Our results suggest that the variability of the transient response is predominately set by heat uptake, not carbon, and that this</span></p><p><span>variability may be traced to individual water masses. Therefore, it may be necessary to separate this transient response regionally in order</span></p><p><span>to obtain accurate estimates of added and redistributed heat at a global scale using this technique. The Eulerian transient response is set</span></p><p><span>predominantly by isotherm heave. The part of the transient response set by climate sensitivity, analogous to a semi-Lagrangian approach, is</span></p><p><span>set largely by patterns of regional heat uptake.</span></p>