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Mixed Layer Depth Comparisons

The carbon model requires mixed layer depth (MLD) as an input variable. It is essential that the best estimation of MLD be used as input. These pages describe the rationale for selection of a final input set for processing.

OTIS MLD Values and Comparison with TOPS ILD Values: Part II

The OTIS data were available from the NCDC archives, starting on September 19, 1997, and continuing until they were replaced by NCODA on October 1, 2004. One major problem, however, is that the OTIS salinity data are corrupted in the archives from May 11, 2000, through August 14, 2002, resulting in more than a two-year gap in the OTIS mixed layer depth estimates.

Because of the change from OTIS to NCODA, and its ensuing differences, it is appropriate to refer to the TOPS ILD fields here as the OTIS/TOPS ILD values, and those that follow are the NCODA/TOPS ILD values.

A complete, month by month comparison of the OTIS/TOPS ILD values, and the OTIS MLD values (where available) are shown below. Given the similarity to the differences between the ILD and MLD fields seen here and those shown by NRL climatologies, I would trust the OTIS MLD estimates over the OTIS/TOPS ILD values. The two+ years of corrupted salinity data in the archives is very unfortunate.

Next, a comparision between the NCODA/TOPS ILD and the NCODA MLD.