For Global Ocean- Delayed Mode in-situ Observations of Ocean Surface Currents. Copernicus Quality Information Document
This document is the Copernicus Marine Environment Monitoring Service for In Situ observations Quality Information Document (QUID) on the global currents product from drifting buoys. This data set contains temperature and velocity time series from Surface Velocity Program (SVP) drifters. They are collected, quality controlled and distributed by the AOML Data Assembly Center (DAC). Then a wind slippage correction is computed. Most of the quality control procedures are performed by AOML. Quality
... d by AOML. Quality of drifter's measurements depends on the platform and on its physical integrity. If the drifter's measurement is in nominal mode, the 15 m depth velocity is measured. If not, the surface current is sampled. This information is provided in the data set and defines the way the wind slippage correction has to be used. A validation control is performed on the velocity and wind slippage correction by comparison to the geostrophic current derived from altimetry products (DUACS/AVISO Team; 2014). In some regions and time period, the number of measurements can be critically low due to the drifter launch time schedule (Figure 1) and their geographical locations, as in high latitudes. Moreover, by construction, the wind slippage correction is not available in some small basins (as the Mediterranean Sea) and during the first and last 50 days of drifter's trajectories.