Dynamic Normal-Mode Initialization for Limited-Area Models: Generalization and Application

Abstract

For the dynamic normal-mode initialization (DNMI) procedure used in the initialization of the limited-area models, it is shown that it does not succeed in initializing higher vertical modes. An improved initialization procedure where the DNMI is performed in the vertical mode space is next formulated. A comparison of the two initialization schemes demonstrates that with the new procedure the initialization of the higher vertical modes can be better accomplished. The need for a better initialization method for limited-area models is prompted by the fact that if the assimilation of the observed estimates of the convective heating toward enhancing the analysis of the divergence is to be achieved, higher vertical modes have to be properly initialized. It is shown that the improved DNMI procedure does succeed in the assimilation of the convective heating information.