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EN4 quality controlled ocean data: Download EN4.2.0

Important information about this dataset:
This is the current version of the dataset. Profiles and analyses with two different sets of bias corrections applied are available: 1) Gouretski and Reseghetti (2010) corrections and 2) Levitus et al (2009) corrections. In both cases the corrections used were updates of the original corrections published in the papers. The following pages give more information about bias corrections for profile data: http://www.nodc.noaa.gov/OC5/XBT_BIAS/xbt_bias.html and http://www.nodc.noaa.gov/OC5/mbt-bias/. Please get in touch if you would like to use data without bias corrections applied or if you would like data with different corrections.

Warning: An error has been disovered in the analysis fields in the Labrador Sea between January 1988 and December 1990 causing the sea water potential temperature field to be much too warm. This appears to primarily affect the analysis depth levels of 373m and 447m. We are aware of the issue and are working on identifying the cause. If you are in need of Labrador Sea data in the meantime the EN.4.1.1 analysis fields are still available here:http://www.metoffice.gov.uk/hadobs/en4/download-en4-1-1.html.

Download profiles - Gouretski and Reseghetti (2010) corrections

These zip files each contain monthly files of the profile data with quality information.

1900s 1910s 1920s
1930s 1940s 1950s
1960s 1970s 1980s
1990s 2000s 2010s

Download objective analyses - Gouretski and Reseghetti (2010) corrections

These tar files contain objective analyses formed from the profile data for each month.

1900s 1910s
1920s 1930s
1940s 1950s
1960s 1970s
1980s 1990s
2000s 2010s

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.4.2.0.profiles.g10.download-list.txt
EN.4.2.0.analyses.g10.download-list.txt
EN.4.2.0.profiles.l09.download-list.txt
EN.4.2.0.analyses.l09.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.4.2.0.profiles.g10.download-list.txt
or
wget -i EN.4.2.0.analyses.g10.download-list.txt
or
wget -i EN.4.2.0.profiles.l09.download-list.txt
or
wget -i EN.4.2.0.analyses.l09.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

Citing the data

When using the data set in a paper, please quote the version number (EN4.2.0), the date the data were downloaded and cite the following:

Good, S. A., M. J. Martin and N. A. Rayner, 2013. EN4: quality controlled ocean temperature and salinity profiles and monthly objective analyses with uncertainty estimates, Journal of Geophysical Research: Oceans, 118, 6704-6716, doi:10.1002/2013JC009067

Where appropriate please also acknowledge the data sources used to create EN4.

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).

  • EN.4.2.0.p.profiles.g10.201606.nc.gz, EN.4.2.0.p.analysis.g10.201606.nc.gz, EN.4.2.0.p.profiles.l09.201606.nc.gz, EN.4.2.0.p.analysis.l09.201606.nc.gz
  • EN.4.2.0.p.profiles.g10.201605.nc.gz, EN.4.2.0.p.analysis.g10.201605.nc.gz, EN.4.2.0.p.profiles.l09.201605.nc.gz, EN.4.2.0.p.analysis.l09.201605.nc.gz
  • Changes compared to EN4.1.1

    The changes compared to EN4.1.1 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 compared to EN4.1.0

    The changes between EN4.2.0 and EN4.1.0 are as follows:

    • A fresh download of the source data.
    • A change of units for practical salinity from psu to 1.
    • Black Sea profiles are no longer automatically rejected.

    Please get in touch if you would like to use EN.4.1.0.

    Changes compared to EN4.0.2

    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.
    • Practical salinity units have been changed from psu to 1.

    References

    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

    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


    Download profiles - Levitus et al. (2009) corrections

    These zip files each contain monthly files of the profile data with quality information.

    1900s 1910s 1920s
    1930s 1940s 1950s
    1960s 1970s 1980s
    1990s 2000s 2010s

    Download objective analyses - Levitus et al. (2009) corrections

    These tar files contain objective analyses formed from the profile data for each month.

    1900s 1910s
    1920s 1930s
    1940s 1950s
    1960s 1970s
    1980s 1990s
    2000s 2010s


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