Introduction:

We have compiled a mixed layer climatology and database (described in Holte et al. 2017) using Argo
profiles and a hybrid method (Holte and Talley 2009) for finding the mixed layer depth (MLD). The
climatology incorporates nearly 2,620,000 Argo profiles (April 2022). The new hybrid algorithm models the general shape of each profile, searches for physical features in the profile, and
calculates threshold and gradient MLDs to assemble a suite of possible MLD values. It then analyzes the patterns in the suite to select a final MLD estimate. Results are also presented for MLDs
calculated using de Boyer Montégut et al.'s (2004) threshold values.
Two forms of Argo MLDs are provided (updated April 2022):
 Mixed layer depths and properties (density, temperature, and salinity) for every profile in the Argo data set.
 Climatology of monthly mixed layer depths (mean, median, maximum, and standard deviation) and properties (mean potential density, conservative temperature, and absolute salinity) averaged into
1 degree bins. These fields are averages over the entire Argo record, producing a representative annual cycle of monthly mixed layer properties.
These files contain the mixed layer depths and properties as calculated by the density algorithm and the density threshold. Each also includes the mixed layer depths calculated by the temperature
algorithm and the temperature threshold. A MATLAB version of the algorithm is also available here. Older versions of
the database are available below.


Data: 
The output includes nearly 2,450,000 delayedmode and realtime Argo profiles, collected between January 2000 and March 2021. The profiles were screened with some simple quality controls.

Mixed layer depths and properties for all Argo profiles: 
The following fields are calculated for each individual Argo profile:
 profile date
 profile latitude
 profile longitude
 float number (WMO number)
 profile number
 status (delayed mode corresponds to 1)
 mixed layer depth from density algorithm
 mixed layer average temperature using density algorithm MLD
 mixed layer average salinity using density algorithm MLD
 mixed layer average potential density using density algorithm MLD
 mixed layer depth from density threshold method
 mixed layer average temperature using density threshold MLD
 mixed layer average salinity using density threshold MLD
 mixed layer average potential density using density threshold MLD
 mixed layer depth from temperature algorithm
 mixed layer depth from temperature threshold method

Monthly mixed layer climatology: 
The climatology is determined by grouping the profiles into 1 degree bins and then calculating the mean, median, maximum, and standard deviation of the MLDs for each month, as well as the monthly
mean mixed layer temperatures, salinities, and potential densities. These variables are calculated separately using the density algorithm and the density threshold. The maximum MLD is calculated as the mean of the three
deepest MLDs. The monthly mean MLDs calculated by the temperature algorithm and the temperature threshold are also included. The climatology contains the following monthly fields averaged into 1 degree bins:
 density algorithm mean MLD
 density algorithm median MLD
 density algorithm maximum MLD
 density algorithm MLD standard deviation
 density threshold mean MLD
 density threshold median MLD
 density threshold maximum MLD
 density threshold MLD standard deviation
 mean mixed layer temperature, salinity, and potential density calculated with the density algorithm mean MLD
 mean mixed layer temperature, salinity, and potential density calculated with the density threhsold mean MLD
 temperature algorithm mean MLD
 temperature threshold mean MLD

Old versions of the database 
Mixed layer depths and properties for every profile in the Argo data set:
Climatology of monthly mixed layer depths:

Acknowledgements: 
If you use this data, please cite it as:
Holte, J., L. D. Talley, J. Gilson, and D. Roemmich (2017), An Argo mixed layer climatology and database, Geophys. Res. Lett., 44, 5618–5626, doi:10.1002/2017GL073426.
The Argo data used to create this climatology were collected and made freely available by the International Argo Program and the national programs that contribute to it.
(http://www.argo.ucsd.edu, http://argo.jcommops.org). The Argo Program is part of the
Global Ocean Observing System. doi.org/10.17882/42182#56126 
Links: 
Holte et al. 2017 (GRL paper describing the climatology)
Holte and Talley 2009 (JTECH paper on the algorithm)
Argo data browser
Ocean Sciences presentation on the Argo MLD climatology
Algorithm MATLAB code and demo
de Boyer Montégut et al. (2004) MLD climatology

