T.1.1 Empirically quantify drivers of O2/OHC trend in a water-mass framework
We will evaluate the evolution of oceanic O2, focussing on how this co-varies with temperature change. We will separate the co-variability into circulation-driven and water mass variability through extension of the method used in Turner et al.TU21. We will use both repeat hydrographic measurements with decadal and global scope, but also have a seasonal to interannual and northern Atlantic focus using quality-controlled Argo data. This will yield the temporal and spatial scales over which O2 varies and provide metrics of O2-change to T2.1, T3.2 and T4.1. We will also examine the co-variability residual to look for evidence of remineralisation driven O2 consumption.
T1.2 BGC-Argo driven simulations targeting bio-parameters for O2
We will use Nordic Seas Argo floats with O2 sensors to construct a 1D coupled physical model (GOTM-FABM). The model physics will be constrained by Argo temperature and salinity profiles to reduce uncertainties related to mixed layer dynamics. We will then simulate the biogeochemistry along each Argo track by coupling the Argo driven physics-model to the NPZD-type model of the regional models of O2Ocean and validate the initial model results against BGC-Argo biochemical profiles and remote sensed data. Finally, we will adjust the model’s biological parameterizations of O2 dynamics towards the Bio-Argo observations.