ENACT/ENSEMBLES (EN3):
quality controlled in situ ocean temperature and salinity profiles

The EN3 data set contains global, sub-surface ocean profiles of (potential) temperature and salinity.  They were quality controlled using a comprehensive set of objective checks developed at the Hadley Centre, Met Office and elsewhere.  The quality control was applied consistently over the whole period, and the checked profiles were output in a uniform format. 

The profiles were obtained primarily from the WORLD OCEAN DATABASE 2005 but this was supplemented using data from other sources - especially GTSPP and Argo GDACs ( USGODAE and Coriolis) for recent years. 

The quality control and processing system was developed and improved for the EU-supported projects ENACT and ENSEMBLES.
It has now been used to process over 9.5 million reports (including duplicates) for the period 1950-2006. The quality controlled reports are available in NetCDF format. 

As part of the processing, monthly 'objective analyses' are produced, in areas where there is no data these relax back towards climatology.  Statistics suggest some improvements in the quality of observations and the objective fields over the last 15 years

Temperature profiles, with spike flagged

The quality control system and some results from it have been described in Ingleby and Huddleston (2007, JMS), and another paper on ocean heat content and observational biases is in preparation. 

The processed observations were extensively used in the ENACT project as input to a variety of data assimilation systems (OI-based, 3D/4D-Var and Ensemble Kalman Filter). The updated version (EN3) is now being similarly used in ENSEMBLES. 

Results from these are being evaluated and published. The data set is being used by other groups including Coriolis and the Bureau of Meteorology (Australia).

Timeseries of global mean T from ENACT analyses