Simulation of the Martian Atmosphere Using a CCSR/NIES AGCM

Abstract

The new simulation of Martian general circulation based on CCSR/NIES AGCM has been performed and the numerical results analyzed. We attempt to reproduce the atmospheric states of Mars which have been observed by the Mars Global Surveyor, and Viking by introducing three kinds of time-and latitudedependent dust opacity scenarios which are made to be consistent with the past observational results, as the observed dust distribution during spring and summer in south hemisphere varies largely at each year and so does observed atmospheric conditions. The model with TES2 dust scenario, which is the dust distribution based on the observation by the Mars Global Surveyor in 1999, generally reproduces distributions of temperature and zonal wind observed by the Mars Global Surveyor in 1999, though the temperature tends to be lower at high altitude. The maximum value of CO 2 ice thickness at polar regions relatively reproduces the observation, but the edge of the northern and southern seasonal caps are outside of the observational results during spring, which results in lower surface pressure especially in northern spring. Annual variations of the amplitudes of the diurnal and semidiurnal tide are qualitatively comparable between our model with VIK1 dust scenario, which is the dust distribution based on the observation by Viking Orbiter in 1977, and observation by Viking Lander 1 in 1977. The baroclinic waves with consistent periods, wavenumbers and phase speeds with observational results by Viking Lander 2 in 1977 are reproduced in the autumn, though in the winter, during the second dust storm, and in the spring, the phase speeds are faster than observation.

Parameterization of radiative heating and cooling rates in the stratosphere of Jupiter

“…This approach has become the most widely used method for parameterizing radiative effects in GCMs for the terrestrial atmosphere (e.g., Lacis and Oinas, 1991;Fu and Liou, 1992;Nakajima et al, 2000;Sekiguchi and Nakajima, 2008) as well as for atmospheres of planets like Venus and Mars (e.g., Eymet et al, 2009;Mischna et al, 2012). In particular, a version of the k-distribution radiative code ''mstrnX'' is being utilized in martian GCMs (Kuroda et al, 2005;Hartogh et al, 2005Hartogh et al, , 2007Medvedev and Hartogh, 2007). This method can be used within a wide range of temperatures, pressures and mole fractions of molecules, retaining much of the accuracy of precise LBL methods.…”

Carbon dioxide ice clouds, snowfalls, and baroclinic waves in the northern winter polar atmosphere of Mars

“…[8] In this study, a modified version of CO 2 condensation/sublimation scheme from Kuroda et al [2005], in which the condensed CO 2 ice was allowed to fall on the surface instantaneously, has been used. The modified version accounts for the finite velocity of gravitational sedimentation, and considers the horizontal and vertical transport of CO 2 ice clouds.…”

“…[7] The MGCM used in this study is based on a terrestrial GCM developed collaboratively between the Center for Climate System Research, University of Tokyo, National Institute of Environmental Studies, and the Frontier Research Center for Global Change (CCSR/NIES/FRCGC) in Japan [K-1 Model Developers, 2004]. It utilizes a spectral solver for the three-dimensional primitive equations, and has a set of physical parameterizations for the martian atmosphere as described in Kuroda et al [2005], which account in particular for the radiative effects of gaseous CO 2 and airborne dust. The model has been validated against the observed zonal mean climatology [Kuroda et al, 2005], and has been applied to the study of baroclinic planetary waves ,zonal-mean variability in mid-andhigh-latitudes [Yamashita et al, 2007], equatorial semiannual oscillations [Kuroda et al, 2008], and winter polar warmings during global dust storms [Kuroda et al, 2009].…”

Structure and dynamics of the Martian lower and middle atmosphere as observed by the Mars Climate Sounder: 2. Implications of the thermal structure and aerosol distributions for the mean meridional circulation

“…Other GCM simulations by Forget et al [1999] and Kuroda et al [2009] differ from that of Wilson [1997] with respect to the atmospheric dust levels or wave forcings necessary to produce a polar warming event, but both simulations produce latitudinally broad and vertically deep mean meridional circulations. Thus, in order to ensure that such a cell can be vertically resolved, current Martian GCMs [e.g., Wilson and Hamilton , 1996; Forget et al , 1999; Takahashi et al , 2003; Moudden and McConnell , 2005; Angelats i Coll et al , 2005; Hartogh et al , 2005; Kuroda et al , 2005; Kahre et al , 2006; Richardson et al , 2007] generally simulate both the lower and middle atmosphere.…”