Global ocean sampling with autonomous floats going to 4,000 m/6,000 m, known as the deep Argo array, constitutes one of the next challenges for tracking climate change. The question here is how such global deep array will impact on ocean reanalyses. Based on the different behavior of four ocean reanalyses, we first identified that large uncertainty exist in current reanalyses in representing local heat and freshwater fluxes in the deep ocean (1 W/m2 and 10 cm/yr regionally). Additionally, temperature and salinity comparison with deep Argo observations demonstrates that reanalysis error in the deep ocean are of the same size, or even stronger, than the deep ocean signal. An experimental approach, using the 1/4◦ GLORYS2V4 system, is then presented to... |