Help with downloading
Use the links on the left to download the EN4 dataset a year at
a time. Available for download are files containing profiles and
files containing the objective analyses with two different sets of
bias corrections. Use the links below to scroll to the section of
the page with the files you want.
If you require the whole dataset one way to do this is to use
wget. To do this download one of the files below (and edit it if
not all files are required).
EN.4.2.2.profiles.g10.download-list.txt
EN.4.2.2.analyses.g10.download-list.txt
EN.4.2.2.profiles.l09.download-list.txt
EN.4.2.2.analyses.l09.download-list.txt
EN.4.2.2.profiles.c13.download-list.txt
EN.4.2.2.analyses.c13.download-list.txt
EN.4.2.2.profiles.c14.download-list.txt
EN.4.2.2.analyses.c14.download-list.txt
Assuming that you are in the directory into which the data are to be
copied and that the downloaded file is also in that directory, the
download can then be initiated by typing at the command line:
wget -i EN.4.2.2.profiles.g10.download-list.txt
or
wget -i EN.4.2.2.analyses.g10.download-list.txt
or
wget -i EN.4.2.2.profiles.l09.download-list.txt
or
wget -i EN.4.2.2.analyses.l09.download-list.txt
or
wget -i EN.4.2.2.profiles.c13.download-list.txt
or
wget -i EN.4.2.2.analyses.c13.download-list.txt
or
wget -i EN.4.2.2.profiles.c14.download-list.txt
or
wget -i EN.4.2.2.analyses.c14.download-list.txt
Note: the above method was written for Linux systems but should
also be applicable to other operating systems with wget installed.
File formats
The data files are stored in zip files. These can be unpacked
using standard utilities such as unzip on Linux systems. Within
the zip files are data files which are in the NetCDF classic
format with support for large files (64 bit offset format). The
contents of these are broadly identical to that used in the
previous version, as summarised in the links below. The profile
files do have some additional information that relate to the
application of bias corrections. These can be used to determine
which profiles were corrected and what the corrections were.
Please contact us for more information if required.
File naming convention
We use a standardised file naming convention. For the zip files
the form is:
dataset.X.Y.Z.type.[E.]year.extension
For the data files an expanded form is used:
dataset.X.Y.Z.θ.type.[E.]date.extension
The sections of the names are:
| dataset |
This is 'EN' for the EN4 dataset |
| X |
The major dataset number (set to 4 for EN4) |
| Y |
Version number that is incremented when there is a major
change to the methodology used to construct the dataset |
| Z |
Version number that is incremented when there is a minor
change to the dataset |
| θ |
For EN4 this is set to 'p' if the file is a preliminary
version or 'f' if the data file has been finalised |
| type |
This is 'profiles' if the file contains profile data. For
objective analysis data it is set to 'analysis' (data files)
or 'analyses' (zip files) |
| E |
If present this indicates that time varying bias
adjustments were applied to the data and the source of the
bias adjustments |
| year |
The year of the data in the file (zip file names only) |
| date |
The date in the form YYYYMM (YYYY = year, MM = month)
(data file names only) |
| extension |
Indicates the file type - this is 'nc' (NetCDF) for all
EN4 data files and 'zip' for zip files |
Product User Guide
A product user guide is available as a pdf. This includes more in depth material including how to work with the bias correction and uncertainty information and a description of the data format.
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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.
Updates
This dataset is updated on a monthly basis. Data are available
about two months after they are collected. Preliminary versions of
the data are generated about a month earlier; these can be
downloaded below when they become available (most recent is listed
first; the files are compressed using gzip and can be uncompressed
using, for example, the Linux gunzip utility).
Changes in EN.4.2.2 compared to EN.4.2.1
The changes compared to EN.4.2.1 are:
- A fresh download of the source data.
- The updating of the values used for the Levitus et al (2009) corrections.
- The use of new Gouretski and Cheng (2020) MBT corrections in the .g10. and .c14. ensemble members. In .g10. these replace the Gouretski and Reseghetti (2010) MBT corrections.
- The addition of corrections to T10 XBTs in the .g10. corrections.
- The addition of Cheng et al (2014) XBT bias corrected data (paired with Gouretski and Cheng (2020) MBT corrections) in the .c14. ensemble member.
- The addition of Cowley et al (2013) XBT bias corrected data (paired with the Levitus et al (2009) MBT corrections) in the .c13. ensemble member.
- The addition of licence and reference attributes to all netCDF files to aid correct citations and use.
- The removal of data from eight TAO buoys between 2015 and 2016 after spurious salinity values were found by a user in EN.4.2.1.
- The removal of a single early Argo float after stuck depths were reported by a user in EN.4.2.1.
Changes in EN.4.2.1 compared to EN.4.2.0
The changes compared to EN.4.2.0 are:
- A fresh download of the source data.
- A removal of the six moored buoys that caused unrealistic temperatures in the analyses in the Labrador Sea between 1988 and 1990.
Changes in EN.4.2.0 compared to EN.4.1.1
The changes compared to EN.4.1.1 are:
- A fresh download of the source data.
- A removal of the wrongly added 273.15 value from the temperature_uncertainty fields in the objective analyses.
- A change of units for practical salinity from psu to 1. This change does not affect the values themselves, but it makes the variable CF compliant.
Changes in EN.4.1.1 compared to EN.4.1.0
The changes between EN.4.1.1 and EN.4.1.0 are as follows:
- A fresh download of the source data.
Changes in EN.4.1.0 compared to EN.4.0.2
The main changes compared to version 4.0.2 of the dataset are:
- A fresh download of the source data.
- Objective analyses formed from bias corrected data are now
available.
- Fixed minor error in the duplicate check.
- GTSPP profiles with data type 'TE' now have some thinning
applied to reduce the density of observations.
- Black Sea observations are no longer automatically rejected.
References
S. Levitus et al., 2009: Global ocean heat content 1955-2008 in
light of recently revealed instrumentation problems. Geophysical
Research Letters, 36, L07608. doi:http://dx.doi.org/10.1029/2008GL037155
Viktor Gouretski and Franco Reseghetti, 2010: On depth and
temperature biases in bathythermograph data: development of a new
correction scheme based on analysis of a global ocean database. Deep-Sea
Research I, 57, 6. doi: http://dx.doi.org/10.1016/j.dsr.2010.03.011
Cowley et al, 2013: Biases in Expendable Bathythermograph Data: A New View Based on Historical Side-by-Side Comparisons. Journal of Atmospheric and Oceanic Technology, 30, 6. doi: https://doi.org/10.1175/JTECH-D-12-00127.1
Cheng et al, 2014: Time, Probe Type, and Temperature Variable Bias Corrections to Historical Expendable Bathythermograph Observations. Journal of Atmospheric and Oceanic Technology, 31, 8. doi: https://doi.org/10.1175/JTECH-D-13-00197.1
Viktor Gouretski and Lijing Cheng, 2020: Correction for Systematic Errors in the Global Dataset of Temperature Profiles from Mechanical Bathythermographs. Journal of Atmospheric Technology and Oceanic Research, 37, 5. doi: https://doi.org/10.1175/JTECH-D-19-0205.1
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