Delayed Mode Quality Control on Argo floats at the Coriolis Data Center

Coatanoan C., Galaup P. & V.Thierry

Coriolis Data Center
IFREMER DOP/DCB/IDM/SISMER
Centre de Brest - BP 70
FRANCE - 29280 PLOUZANE
France

A remote calibration method is required to correct salinity sensor drifts by using hydrographic reference database. At the Coriolis data center, the Wong et al method, adapted by Böhme and Send, has been applied to the North Atlantic environment to produce delayed mode dataset; a large coordination has taken place between the PI and the data center to study the results of the method. Since this application has been done on some floats older than two years, it appears that some of them show offsets or drifts, at least for the latest cycles. Most of them can be easily corrected from the DMQC method, but from this first experience, we can mention that when the float shows an irregular behaviour, specially when a significant drift appears, we need to apply specific procedures. Some statistical results will present the ratio of corrections applied to the float of the North Atlantic Ocean. Extrapolations of correction for the real time data will be analyzed. Complementary diagnostic plots have been also developed at the Coriolis Data Center to compare DMQC results with temperature and salinity residuals and fields of the objective analysis. In an other way, to be able to properly apply the Wong-Böhme method, a major point is to have a relevant reference dataset, which should be supplied by the CTD carried out during the float deployment.