•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.