A spectral model of the atmospheric general circulation of Mars: A numerical experiment including the effects of the suspended dust and the topography

Abstract

A numerical experiment of the Martian atmospheric general circulation was performed by using a spectral three‐level linear‐balance model. We examined effects of topography and of radiative scattering of dust suspended in the Martian atmosphere upon the general circulation. Computations were made for a period corresponding to the equinoctial season for the southern hemisphere. Our results indicate that in the stage of development of a dust storm, topography, when it exists in the dusty field, would have a very important role for intensifying winds and suspending dust particles blown up from the surfaces in such a specified region as the Hellas region and that thermally forced transient waves produced by radiative effect of dust are superposed on the quasistationary disturbances induced by the topography. As a result, large coupled oscillations appear in the atmosphere, especially in the temperature fields, having the predominant components of wave number 1 and 2 which would correlate with diurnal and semidiurnal wave components, respectively.

Interannual Variability of Martian Global Dust Storms Simulations with a Low-Order Model of the General Circulation

“…Previous attempts to simulate the GDSs employed interactive 2D models (Haberle et al 1982 or full 3D GCMs with a prescribed dust source and fixed dust distributions (Moriyama and Iwashima 1980, Pollack et al 1990, Murphy et al 1995. Simulations with a prescribed dust source produce results that are in good agreement with available observations.…”

“…They include the zonally symmetric models (Haberle et al 1982 and truncated spectral models (Haberle et al 1997, Moriyama andIwashima 1980). In the zonally symmetric models longitudinal variations are neglected, while in the spectral models the set of basis functions is severely truncated to yield a state space of lesser dimension.…”

Interannual variability of Mars global dust storms: an example of self-organized criticality?

“…If this hypothesis is correct, it raises the question of why the system is so finely tuned. Published general circulation model (GCM) studies do not exhibit interannual variability (Moriyama and Iwashima, 1980;Haberle et al, 1982;Pollack et al, 1990;Murphy et al, 1993;1995;Newman et al, 2003a;2003b). In an unpublished study, Basu et al (2003) were able to simulate interannual variability, but only for a very limited range of dust injection rates and threshold wind speed.…”

Linear baroclinic instability in the Martian atmosphere: Primitive equation calculations

“…Previous studies have also employed general circulation models (GCM) to simulate the Martian atmosphere (e.g., Leovy and Mintz, 1969;Moriyama and Iwashima, 1980;Pollack et al, 1990;Barnes et al, 1993;Hollingsworth and Barnes, 1996;Wilson and Hamilton, 1996). Since Mars and Earth have similar astronomical parameters (e.g., rotation rate, size, atmospheric scale height), a well established technique developed for the terrestrial atmosphere may be applicable to the Martian atmosphere.…”