Status of the Deep Argo float array and scientific breakthroughs

– Nathalie Zilberman, Scripps Institution of Oceanography) –

Résumé :

The deep ocean below 2000 m, which represents half of the total ocean volume, is one of the most unexplored areas on Earth. While observations in the upper 2000 m have dramatically increased with the implementation of the global Core Argo float array, the deep ocean below remains highly under sampled. Only 10% of historical upper 2000-m ocean temperature and salinity profiles extend to the seafloor. Deep Argo floats are a model of Argo float that can withstand 3 times the pressure of a Core Argo float and reach 6000 m, allowing to sample from the sea surface to the seafloor. Here, I will be reporting on progress achieved with the design of several successful Deep Argo float models and increased float longevity, technology development of Deep Argo conductivity-temperature-depth (CTD), and implementation of quality control procedures to increase the scientific value of the dataset. About 200 Deep Argo floats are sampling the deepest regions of the ocean. Due to limited funded resources, annual float deployment rates in the past 2 years are insufficient to implement a global Deep Argo float array. In well-sampled regions, Deep Argo has enabled scientific breakthroughs in our understanding of ocean heat content, sea level change, and ocean circulation. A new Deep Argo based bathymetry dataset that does not require any change in the Deep Argo mission parameters or integration of additional sensors will also be described.