ANDRO: An Argo-Based Deep Displacement Dataset

During the first decade of the twenty-first century, more than 6000 Argo floats have been launched over the World Ocean, gathering temperature and salinity data from the upper 2000 m, at a 10-day or so sampling period. Meanwhile their deep displacements can be used to map the ocean circulation at their drifting depth (mostly around 1000 m). A comprehensive processing of the whole Argo dataset collected prior to 1 January 2010 has been performed to produce a world-wide dataset of deep displacements. This numerical atlas, named ANDRO, after a traditional dance of Brittany meaning a swirl, comprises some 600 000 deep displacements. These displacements, based on Argo or GPS surface locations only, have been fully checked and corrected for possible errors found in the public Argo data files (due to incorrect decoding or instrumental failure). Park pressures measured by the floats while drifting at depth are preserved in ANDRO (less than 2% of the park pressures are unknown): 63% of the float displacements are in the layer (900, 1100) dbar with a good (more or less uniform) degree of coverage of all the oceans, except around Antarctica (south of 60 degrees S). Two deeper layers-(1400, 1600) and (1900, 2100) dbar-are also sampled (11% and 8% of the float displacements, respectively) but with poorer geographical coverage. Grounded cycles (i.e., if the float hits the sea bottom) are excluded. ANDRO is available online as an ASCII file.