The effects of topographically-controlled thermal tides in the martian upper atmosphere as seen by the MGS accelerometer

Withers, Paul; Bougher, S. W.; Keating, G. M.

doi:10.1016/s0019-1035(03)00135-0

Cited by 115 publications

(205 citation statements)

References 31 publications

Supporting

Mentioning

183

Contrasting

Order By: Relevance

“…Compared to other Mars GCM work, (Bougher and Dickinson, 1988), (Bougher, a), (Withers, 2003), the MarTIM horizontal wind speeds are low. The other GCM results generally show winds of the order of 100ms…”

Section: Horizontal Wind Flowmentioning

confidence: 54%

“…Figures 7 and 8, when compared to Figures 5 and 6 respectively, do show an increase in the high altitude winds, although not enough to agree with the expected magnitudes, (Bougher and Dickinson, 1988), (Bougher, a), (Withers, 2003). The region close to the lower boundary has seen the most change.…”

Section: The (22) Semi-diurnal Tidementioning

confidence: 65%

“…• man and Lindzen, 1970) and have been studied though GCM simulations and data analysis. Recent work on the available data has shown the presence of similar tides on Mars, (Withers, 2003), and one of the main migrating tides (the semi-diurnal (2,2) tide) that reaches thermospheric altitudes, (Forbes, 2004), (Bougher et al, 1993), is input into MarTIM. Terrestrial tides have been well studied using classical tidal theory, (Chapman and Lindzen, 1970).…”

Section: The (22) Semi-diurnal Tidementioning

confidence: 99%

“…Recent work on the available data has shown the presence of similar tides on Mars (Withers, 2003) and one of the main migrating tides (the semi-diurnal (2,2) tide) that reaches thermospheric altitudes (Forbes, 2004;Bougher et al, 1993), is input into MarTIM.…”

Section: The (22) Semi-diurnal Tidementioning

confidence: 99%

“…Temperature profiles are in good agreement with Pathfinder results. Wind velocities are slightly lower compared to analysis of MGS accelerometer data (Withers, 2003). The novel step-by-step approach of adding in new features to MarTIM has resulted in further understanding of the drivers of the Martian thermosphere.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Thermal structure and dynamics of the Martian upper atmosphere at solar minimum from global circulation model simulations

2007

View full text Add to dashboard Cite

Abstract. Simulations of the Martian upper atmosphere have been produced from a self-consistent three-dimensional numerical model of the Martian thermosphere and ionosphere, called MarTIM. It covers an altitude range of 60 km to the upper thermosphere, usually at least 250 km altitude. A radiation scheme is included that allows the main sources of energy input, EUV/UV and IR absorption by CO 2 and CO, to be calculated. CO 2 , N 2 and O are treated as the major gases in MarTIM, and are mutually diffused (though neutral chemistry is ignored). The densities of other species (the minor gases), CO, Ar, O 2 and NO, are based on diffusive equilibrium above the turbopause. The ionosphere is calculated from a simple photoionisation and charge exchange routine though in this paper we will only consider the thermal and dynamic structure of the neutral atmosphere at solar minimum conditions. The semi-diurnal (2,2) migrating tide, introduced at MarTIM's lower boundary, affects the dynamics up to 130 km. The Mars Climate Database (Lewis et al., 2001) can be used as a lower boundary in MarTIM. The effect of this is to increase wind speeds in the thermosphere and to produce small-scale structures throughout the thermosphere. Temperature profiles are in good agreement with Pathfinder results. Wind velocities are slightly lower compared to analysis of MGS accelerometer data (Withers, 2003). The novel step-by-step approach of adding in new features to MarTIM has resulted in further understanding of the drivers of the Martian thermosphere.

show abstract

Section: Horizontal Wind Flowmentioning

confidence: 54%

Section: The (22) Semi-diurnal Tidementioning

confidence: 65%

Section: The (22) Semi-diurnal Tidementioning

confidence: 99%

Section: The (22) Semi-diurnal Tidementioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Thermal structure and dynamics of the Martian upper atmosphere at solar minimum from global circulation model simulations

2007

View full text Add to dashboard Cite

show abstract

Hot carbon corona in Mars’ upper thermosphere and exosphere: 1. Mechanisms and structure of the hot corona for low solar activity at equinox

Lee

Combi

Tenishev

et al. 2014

J. Geophys. Res. Planets

View full text Add to dashboard Cite

Two important source reactions for hot atomic carbon on Mars are photodissociation of CO and dissociative recombination of CO + ; both reactions are highly sensitive to solar activity and occur mostly deep in the dayside thermosphere. The production of energetic particles results in the formation of hot coronae that are made up of neutral atoms including hot carbon. Some of these atoms are on ballistic trajectories and return to the thermosphere, and others escape. Understanding the physics in this region requires modeling that captures the complicated dynamics of hot atoms in 3-D. This study evaluates the carbon atom inventory by investigating the production and distribution of energetic carbon atoms using the full 3-D atmospheric input. The methodology and details of the hot atomic carbon model calculation are given, and the calculated total global escape of hot carbon from the assumed dominant photochemical processes at a fixed condition, equinox (L s = 180°), and low solar activity (F10.7 = 70 at Earth) are presented. To investigate the dynamics of these energetic neutral atoms, we have coupled a self-consistent 3-D global kinetic model, the Adaptive Mesh Particle Simulator, with a 3-D thermosphere/ionosphere model, the Mars Thermosphere General Circulation Model to provide a self-consistent global description of the hot carbon corona in the upper thermosphere and exosphere. The spatial distributions of density and temperature and atmospheric loss are simulated for the case considered.

show abstract

Mars Global Ionosphere‐Thermosphere Model: Solar cycle, seasonal, and diurnal variations of the Mars upper atmosphere

et al. 2015

View full text Add to dashboard Cite

A new Mars Global Ionosphere-Thermosphere Model (M-GITM) is presented that combines the terrestrial GITM framework with Mars fundamental physical parameters, ion-neutral chemistry, and key radiative processes in order to capture the basic observed features of the thermal, compositional, and dynamical structure of the Mars atmosphere from the ground to the exosphere (0-250 km). Lower, middle, and upper atmosphere processes are included, based in part upon formulations used in previous lower and upper atmosphere Mars GCMs. This enables the M-GITM code to be run for various seasonal, solar cycle, and dust conditions. M-GITM validation studies have focused upon simulations for a range of solar and seasonal conditions. Key upper atmosphere measurements are selected for comparison to corresponding M-GITM neutral temperatures and neutral-ion densities. In addition, simulated lower atmosphere temperatures are compared with observations in order to provide a first-order confirmation of a realistic lower atmosphere. M-GITM captures solar cycle and seasonal trends in the upper atmosphere that are consistent with observations, yielding significant periodic changes in the temperature structure, the species density distributions, and the large-scale global wind system. For instance, mid afternoon temperatures near ∼200 km are predicted to vary from ∼210 to 350 K (equinox) and ∼190 to 390 k (aphelion to perihelion) over the solar cycle. These simulations will serve as a benchmark against which to compare episodic variations (e.g., due to solar flares and dust storms) in future M-GITM studies. Additionally, M-GITM will be used to support MAVEN mission activities (2014)(2015)(2016).

show abstract

The effects of topographically-controlled thermal tides in the martian upper atmosphere as seen by the MGS accelerometer

Cited by 115 publications

References 31 publications

Thermal structure and dynamics of the Martian upper atmosphere at solar minimum from global circulation model simulations

Thermal structure and dynamics of the Martian upper atmosphere at solar minimum from global circulation model simulations

Hot carbon corona in Mars’ upper thermosphere and exosphere: 1. Mechanisms and structure of the hot corona for low solar activity at equinox

Mars Global Ionosphere‐Thermosphere Model: Solar cycle, seasonal, and diurnal variations of the Mars upper atmosphere

Contact Info

Product

Resources

About