A global monthly climatology of the mixed layer depth (MLD), obtained with a physically derived and energy-based methodology (EBM), is provided. This climatology defines the mixed layer as the energetically homogeneous upper ocean layer in which water parcels can move with little or no buoyancy work; the mixed layer is representative of seasonal timescales, without addressing the diurnal mixing cycle or the timescales in which mixing is currently active. This approach provides a robust criterion in determining the MLD, which is reliable across diverse ocean conditions, globally and temporally consistent, and easy to implement.

The available dataset contains the monthly climatology of mixed layer depth and derived variables over the global ocean, with a spatial resolution of 2° x 2°. This climatology is based on approximately 2 million in situ Argo profiles from January 2005 to December 2023. The MLD and derived variables were computed for each profile within a grid cell for each month in the long-term record; the resulting values were then averaged to obtain a representative value for that grid cell and month. The file contains the following variables, in addition to latitude, longitude, and month:

• mld: Global monthly climatology of the mixed layer depth calculated with the energy-based methodology.
• wb: Global monthly climatology of the threshold in the work done by buoyancy characterizing the EBM-MLD.
• rho: Global monthly climatology of the absolute differences in potential density from the reference depth of 10 m to the EBM-MLD.
• temp: Global monthly climatology of the absolute differences in conservative temperature from the reference depth of 10 m to the EBM-MLD.