Abstract:A new initialization scheme used for the five-level primitive equationmodel in the Northern Hemisphere (designated as Model B for sim-plicity) is given. The procedure is as follows. First, 5 verticalmodes of the corresponding linearized primitive equations in the so-called mixed coordinates are evaluated. Then a chosen objective ana-lyzed wind field and a geopotential field are expanded in terms ofthese modes. Finally, by using the variational iteration technique,the high-frequency gravity waves and short waves originally containedin the initial data can be considerably suppressed. The numericalresults show that this new scheme could avoid "kinetic energy loss"often found in other initialization procedures. Case studies indicatethat 24-hr forecasts of geopotential fields with the scheme are muchbetter than those with the original model, i.e., the balance equation. For instance, by using the scheme, the flaws of underesti-mating the intensity of closed highs and lows, troughs and ridges withthe original model can be remedied to a certain extent. In addition,the forecast 24-hr precipitation amounts are generally greater thanobtained by the original model but still smaller than the observedvalues.