Adiabatic and Diabatic Initialization of the AFGL Global Spectral Model Using Dynamic Normal Mode and Nonlinear Normal Mode Methods

Download or read book Adiabatic and Diabatic Initialization of the AFGL Global Spectral Model Using Dynamic Normal Mode and Nonlinear Normal Mode Methods written by Larry Knowlton and published by . This book was released on 1989 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic normal mode initialization (DNI) is applied to low and high resolution versions of the AFGL global spectral mode. This scheme is tested against the operational nonlinear normal mode initialization (NMI) procedure using both adiabatic and diabatic forms of the model tendencies. The DNI-based forecasts are comparable in accuracy to the NMI-based forecasts, with small differences between the adiabatic and diabatic versions of each. DNI initial conditions were somewhat more damped in the divergence fields than were the NMI fields. This is believed to be due to the frequency response characteristics of the DNI's forward-backward time scheme, which tended to partially damp resolvable wavelengths.