A modified atmospheric non-hydrostatic model on low aspect ratio grids
MetadataShow full item record
It is popular to use a horizontal explicit and a vertical implicit (HE-VI) scheme in the compressible nonhydrostatic (NH) model. However, when the aspect ratio becomes small, a small time-interval is required in HE-VI, because the Courant-Fredrich-Lewy (CFL) criterion is determined by the horizontal grid spacing. Furthermore, simulations from HE-VI can depart from the forward–backward (FB) scheme in NH even when the time interval is less than the CFL criterion allowed. Hence, a modified non-hydrostatic (MNH) model is proposed, in which the left-hand side of the continuity equation is multiplied by a parameter d (45d516, in this study). When the linearized MNH is solved by FB (can be other schemes), the eigenvalue shows that MNH can suppress the frequency of acoustic waves very effectively but does not have a significant impact on the gravity waves. Hence, MNH enables to use a longer time step than that allowed in the original NH. When the aspect ratio is small, MNH solved by FB can be more accurate and efficient than the NH solved by HE-VI. Therefore, MNH can be very useful to study cloud, Large Eddy Simulation (LES), turbulence, flow over complex terrains, etc., which require fine resolution in both horizontal and vertical directions.
© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tellus A 64 (2012): 17516, doi:10.3402/tellusa.v64i0.17516.
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Sun, Wen-Yih; Sun, Oliver M. T.; Tsuboki, Kazuhisa (International Meteorological Institute, 2013-06-28)Sun et al. (2012) proposed a modified non-hydrostatic model (MNH), in which the left-hand side of the continuity equation is multiplied by a parameter δ(4 ≤ δ≤16 in the article) to suppress high-frequency acoustic waves. ...
Frequency-dependent two-sex models : a new approach to sex ratio evolution with multiple maternal conditions Shyu, Esther; Caswell, Hal (John Wiley & Sons, 2016-09-07)Mothers that experience different individual or environmental conditions may produce different proportions of male to female offspring. The Trivers-Willard hypothesis, for instance, suggests that mothers with different ...
Acoustic scattering from sand dollars (Dendraster excentricus) : modeling as high aspect ratio oblate objects and comparison to experiment Dietzen, Gregory C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2008-09)Benthic shells can contribute greatly to the scattering variability of the ocean bottom, particularly at low grazing angles. Among the effects of shell aggregates are increased scattering strength and potential subcritical ...