Pacific Fisheries Environmental Laboratory
World Ocean Database 1998
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Standard Level 1-degree Summaries
The monthly climatology is calculated from 1945 to 1996 at 33 standard depth levels (0 - 5500 m). Monthly averaged temperature is available at 19 standard depth levels (0 - 1000 m). The following variables are available along with the number of observations averaged in each 1 degree lat/lon box for each variable:
Mixed Layer Depth
Also available on the Live Access Server are monthly mixed layer depth and mixed layer depth climatology computed from the WOD98 standard level data. Mixed layer depth is computed using two different criteria (see below) from individual WOD98 profiles, then averaged on a 1-degree latitude/longitude grid.
Temperature Criterion: Mixed layer depth is determined as the depth at which the temperature falls to 0.5 degrees C below the surface temperature.
Density Criterion: Mixed layer depth is determined as the depth at which the density difference from the sea surface is 0.125 sigma units.
For more details, on the criteria see: Monterey, G., and S. Levitus, 1997: Seasonal variability of mixed layer depth for the World Ocean. NOAA Atlas, NESDIS 14, 100 pp., Washington, D.C.
Follow this link for additional plots of MLD climatology including plots of MLD computed using a variable density criterion.