Affiliation:
1. Institute of Physics and Mathematics, Pelotas State University, Pelotas, Brazil
Abstract
Abstract
Balance equations of normal-mode initialization are nonlinear time-independent partial differential equations solved by iterative methods. For the given geopotential, there are regions where these equations are not elliptic, which is reflected in the divergence of iterative algorithms. Variational approaches used to minimize the geopotential changes are more expensive than conventional methods. In this study a simple quasi-variational algorithm is proposed based on different forms of normal-mode initialization equations, which achieves a good balance of atmospheric fields and ensures small changes of geopotential analysis values.
Publisher
American Meteorological Society
Reference35 articles.
1. A routine for normal mode initialization with nonlinear correction for a multilevel spectral model with triangular truncation.;Andersen,1977
2. Adjustments of initial conditions required to supress gravity oscillations in nonlinear flows.;Baer;Contrib. Atmos. Phys.,1977
3. A simple test of the initialization of gravity modes.;Ballish;Mon. Wea. Rev.,1981
4. Initialization of a limited area model: A comparison between the nonlinear normal mode and bounded derivative methods.;Bijlsma;Mon. Wea. Rev.,1986
5. Ellipticity of normal mode initialization equations.;Bourchtein;Appl. Math. Comput.,2002