Affiliation:
1. Institute of Physics and Mathematics
Abstract
To eliminate the fast gravitational waves of great amplitude, which are not observed in the real atmosphere, the initial fields for numerical schemes of atmosphere forecasting and modeling systems are usually adjusted dynamically by applying balance relations. In this study we consider different forms of the balance equations and for each of them we detect the nonelliptic regions in the gridded atmosphere data of the Southern Hemisphere. The performed analysis reveals the geographical, vertical and zonally averaged distributions of nonelliptic regions with the most concentration in the tropical zone. The area of these regions is essentially smaller and less intensive for more complete and physically justified balance relations. The obtained results confirm the Kasaharas assumption that ellipticity conditions are violated in the actual atmospheric fields essentially due to approximations made under deriving the balance equations.
Reference26 articles.
1. On complete filtering of gravity modes through nonlinear initialization;Baer F;Mon. Wea. Rev.,1977
2. Four-dimensional assimilation of meteorological observations;Bengtsson L,1975
3. Initialization of a limited area model: a comparison between the nonlinear normal mode and bounded derivative methods;Bijlsma S.J;Mon. Wea. Rev.,1986
4. Ellipticity of normal mode initialization equations;Bourchtein A;Appl. Math. Comput.,2002
5. Ellipticity conditions of the shallow water balance equations for atmospheric data;Bourchtein A;J. Atmos. Sci.,2006