The algorithm displayed on this page is dubbed DTF50 (Diagnostic Turbulence Function 5.0).  It is based on the E-g  turbulence model (XU and Taylor, 1997; Speziale, 1991; Langland and Liou, 1996; Ramanathan et al., 1995).  This model is composed of two tendency equations; one for the turbulent kinetic energy, E; and the other for the dissipation rate of turbulence, g.  This particular model has been calibrated and tested with boundary layer data in many occasions.  For more information on this product, see the TKE information page.