The Model (11)
•Two hybrid-coordinate K-T mixed layer models have been developed.
–K-T 1: Full model
•This version has a prognostic mixed layer base. At a given grid point, the base is contained within layer k and divides this layer into two sublayers (see diagram on previous slide). T and S are estimated within these sublayers by “unmixing” each variable, then the TKE balance is calculated as in the MICOM K-T mixed layer.
–K-T 2: Simplified model
•This version was developed by Rainer Bleck to avoid unmixing and the associated computational overhead. At each grid point, the mixed layer base always resides on a vertical coordinate interface.
•When HYCOM is run in MICOM mode, the MICOM 2.8 Kraus-Turner mixed layer model is used. The mixed layer base coincides with vertical coordinate interface 2 (layer 1 is the slab mixed layer). Another major difference from the hybrid-coordinate K-T models is the detrainment algorithm, since the density of detrained water must match the isopycnic reference density of the layer accepting the water.