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EN4 quality controlled ocean data: Select version to download

Current version

The current version of the EN4 dataset is EN.4.2.2. This will be updated each month with new data. Profiles and analyses are available with four different time varying bias adjustments applied to expendable bathythermograph (XBT) data and two different time varying bias adjustments applied to mechanical bathythermograph (MBT) data. Please contact us if you have a particular requirement that is not met by these data.

Previous versions


EN.4.2.1 is relatively similar to its sucessor, EN.4.2.2, but EN.4.2.2 incorporates updates to XBT and MBT bias correction schemes and two additional XBT bias correction schemes (Cowley et al (2013) and Cheng et al (2014). EN.4.2.2 removes sections of data from eight TAO buoys between 2015 and 2016 after these were shown to have spurious salinity values and also removes one early Argo float with stuck temperature values. EN.4.2.2 was also built from a fresh download of the source data and now contains licence and reference attributes in all its netCDF fields. EN.4.2.2 also underwent new quality assurance checks during its production, primarily to ensure that any large differences from EN.4.2.1 were appropriately investigated. Where such differences occurred they were primarily found to result from the extra data in EN.4.2.2 and were deemed to be appropriate.

There is one variable change in the .g10. data in EN.4.2.2 compared to EN.4.2.1. In EN.4.2.1 the .g10. data contained a variable 'stretch_corrections', which provided the values that the uncorrected depths had been multiplied by in order to get the corrected depths. In EN.4.2.2 the .g10. data contain the variable 'depth_corrections' instead, this provides the value that has been subtracted off the uncorrected depths in order to get the corrected depths which are those included in the files.

Profile data and objective analyses are available:

If you require access to earlier versions of EN4 then please contact us.

Citing the data

Please see the terms and conditions page for the appropriate way to cite the EN4 data, its bias corrections and its sources.

Commercial and media enquiries

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