AN OPERATIONAL 5-LAYER PRIMITIVE EQUATION MODEL FOR NORTHERN HEMISPHERE PREDICTION

A 5-layer primitive equation Northern Hemisphere operational model in a modified σ-coordinate system is developed in BMC, NMB. Finite difference schemes are constructed to conserve the total energy without imposing any constraints on the difference scheme of hydrostatic equation and pressure gradient term.The physical factors of orography, friction, horizontal diffusion and various non-adiabatic heatings are included.The model has been under development since the beginning of 1980, and became operational in September 1981. Preliminary results for selected series of 40 prognosis are summarized and the verifications are encouraging.