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The Thermal Emission Spectrometer aboard the Mars Global Surveyor spacecraft has produced an extensive atmospheric data set, beginning during aerobraking and continuing throughout the extended scientific mapping phase. Temperature profiles for the atmosphere below about 40 km, surface temperatures and total dust and water ice opacities, can be retrieved from infrared spectra in nadir viewing mode...
Oxygen and carbon isotope ratios in the martian CO 2 are key values to study evolution of volatiles on Mars. The major problems in spectroscopic determinations of these ratios on Mars are uncertainties associated with: (1) equivalent widths of the observed absorption lines, (2) line strengths in spectroscopic databases, and (3) thermal structure of the martian atmosphere during the observation...
A strong, broad spectral emission feature at 85° N latitude centered at 221 cm −1 remains unidentified after candidate ices of H 2 O and pure crystalline CH 3 CH 2 CN are unambiguously ruled out. A much shallower weak emission feature starts at 160 cm −1 and blends into the strong feature at ∼190 cm −1 . This feature is consistent with one formed by...
Accelerometer measurements made by Spirit and Opportunity during their entries through the martian atmosphere are reported. Vertical profiles of atmospheric density, pressure, and temperature with sub-km vertical resolution were obtained using these data between 10 and 100 km. Spirit's temperature profile is ∼10 K warmer than Opportunity's between 20 and 80 km. Unlike all other martian entry profiles,...
In this work we estimate the minimum persistence time of subsurface ice in water rich sediment layers remaining after sublimation of a martian lake. We simulate sublimation of ice from layers of different granulations and thicknesses. Presented results assume insolation and atmospheric conditions characteristic for the present day southern Elysium, where data from Mars Express have identified surface...
We use infrared spectra returned by the Mars Global Surveyor Thermal Emission Spectrometer (TES) to retrieve atmospheric and surface temperature, dust and water ice aerosol optical depth, and water vapor column abundance. The data presented here span more than two martian years (Mars Year 24, L s =104 o , 1 March 1999 to Mars Year 26, L s =180 o , 4 May 2003). We present...
A method for separating the spectral signatures of the Martian surface and atmosphere was developed and is applied to multiple emission angle data returned from the MGS TES instrument. This method includes correlated-k and index gas removal algorithms that may be applied to all nadir-pointing TES data. Initial results have provided new and refined measurements of the spectral shapes of atmospheric...
The initiation and evolution of a planet-encircling dust storm on Mars have been observed in unprecedented detail by the Thermal Emission Spectrometer (TES) on board the Mars Global Surveyor. A local dust storm began to expand quickly on 26 June 2001 (areo-centric longitude, L s =185 o ), becoming a planet-encircling dust storm by 11 July 2001. The dust storm had dust optical depth...
The “quench level” approximation for estimating the observed abundance of chemically reacting species in the presence of convective dynamics states that the chemical reaction is quenched at the level where the time scales for the chemical reaction,t chem , and for convective dynamics,t dyn , are equal. The dynamical time constant,t dyn , can be computed usingt dyn =L...
We present an algorithm for the retrieval of temperature in the planetary boundary layer (lowest few kilometers) of the martian atmosphere using upward-looking infrared spectra from a Mars lander. Temperature profiles retrieved from an orbiting or passing spacecraft do not have adequate vertical resolution to provide significant information within the planetary boundary layer. By using spectra taken...
We investigate the influence of atmospheric dynamics on the isotopic enrichment factor of monodeuterated methane,f(z) = (D/H) CH4 /(D/H) H2 , in the outer planets. We explore the influence of dynamics using three classes of models. In the first two, we briefly discuss the simple approaches that have previously been used to account for dynamics in the determination off(z). We discuss...
The orientations of the small cloud streaks that are always found at mid-latitudes in ultraviolet images of the Venus cloud-top provide a means for characterizing the global-scale circulation, including the wind field on the night side of Venus. Assuming that small clouds act as passive tracers of the cloud-top wind field, the orientation of cloud streaks is determined by the wind shear that the cloud...
Convective adjustment and diffusive schemes based on terrestrial methods are extended to outer planet applications in order to develop an algorithm that can be used in dynamical modeling of outer planetary flows. Over the temperature range between 50 K and 250 K the delayed conversion of ortho- hydrogen to para-hydrogen can have large effects on stratification. One-dimensional modeling of atmospheric...
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