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Wave analysis in the atmosphere of Venus below 100-km altitude, simulated by the LMD Venus GCM
Lebonnois, Sébastien; Sugimoto, Norihiko; Gilli, Gabriella
A new simulation of Venus atmospheric circulation obtained with the LMD Venus GCM is described and the simulated wave activity is analyzed. Agreement with observed features of the temperature structure, static stability and zonal wind field is good, such as the presence of a cold polar collar, diurnal and semi-diurnal tides. At the resolution used…
Orbital and physical characteristics of meter-scale impactors from airburst observations
Brown, P.; Clark, D.; Wiegert, P. +1 more
We have analyzed the orbits and ablation characteristics in the atmosphere of 59 Earth-impacting fireballs, produced by meteoroids 1 m in diameter or larger, described here as meter-scale. Using heights at peak luminosity as a proxy for strength, we determine that there is roughly an order of magnitude spread in strengths of the population of mete…
Variations of water vapor and cloud top altitude in the Venus' mesosphere from SPICAV/VEx observations
Montmessin, F.; Fedorova, A.; Korablev, O. +3 more
SPICAV VIS-IR spectrometer on-board the Venus Express mission measured the H2O abundance above Venus' clouds in the 1.38 µm band, and provided an estimation of the cloud top altitude based on CO2 bands in the range of 1.4-1.6 µm. The H2O content and the cloud top altitude have been retrieved for the com…
Venus' radar-bright highlands: Different signatures and materials on Ovda Regio and on Maxwell Montes
Treiman, Allan; Harrington, Elise; Sharpton, Virgil
Venus' highlands appear much brighter than its lowland plains in reflected radar, which has been explained by several conflicting hypotheses. We study this transition at higher spatial and elevation resolution than previously possible by combining Magellan synthetic aperture radar (SAR) images with Magellan SAR stereo elevations. We confirm that S…
Aerosol properties in the upper haze of Venus from SPICAV IR data
Vandaele, A. C.; Montmessin, F.; Fedorova, A. +5 more
SPICAV IR, a channel of the SPICAV/SOIR suite of instruments onboard Venus Express spacecraft measured spectra in nadir and solar occultation modes in the range of 0.65-1.7 µm. We report results from 222 solar occultations observed from May 2006 to November 2014. The vertical resolution of measurements varies from 1 to 25 km depending on the…
Properties of planetward ion flows in Venus' magnetotail
Futaana, Y.; Zhang, T. L.; Rong, Z. J. +3 more
Venus is gradually losing some of its atmosphere in the form of ions through its induced magnetotail. Some of these ions have been reported previously to flow back to the planet. Proposed drivers are magnetic reconnection and deflection of pickup ions in the magnetic field. We analyze protons and oxygen ions with eV to keV energies acquired by the…
Themis Regio, Venus: Evidence for recent (?) volcanism from VIRTIS data
Helbert, Joern; Stofan, Ellen R.; Smrekar, Suzanne E. +1 more
Themis Regio is interpreted to be a hotspot rise underlain by one or more mantle plumes. Many volcanic features in the Themis region have high emissivity anomalies in Venus Express Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) data. Other high emissivity anomalies have been found to correspond to volcanic flows interpreted to be relat…
Improved automatic estimation of winds at the cloud top of Venus using superposition of cross-correlation surfaces
Horinouchi, Takeshi; Ikegawa, Shinichi
Accurate wind observation is a key to study atmospheric dynamics. A new automated cloud tracking method for the dayside of Venus is proposed and evaluated by using the ultraviolet images obtained by the Venus Monitoring Camera onboard the Venus Express orbiter. It uses multiple images obtained successively over a few hours. Cross-correlations are …
Radiative energy balance of Venus based on improved models of the middle and lower atmosphere
Kappel, D.; Drossart, P.; Piccioni, G. +4 more
The distribution of sources and sinks of radiative energy forces the atmospheric dynamics. The radiative transfer simulation model described by Haus et al. (2015b) is applied to calculate fluxes and temperature change rates in the middle and lower atmosphere of Venus (0-100 km) covering the energetic significant spectral range 0.125-1000 µm.…
Carbon monoxide observed in Venus' atmosphere with SOIR/VEx
Vandaele, A. C.; Thomas, I. R.; Trompet, L. +6 more
The SOIR instrument on board the ESA Venus Express mission has been operational during the complete duration of the mission, from April 2006 up to December 2014. Spectra were recorded in the IR spectral region (2.2-4.3 µm) using the solar occultation geometry, giving access to a vast number of ro-vibrational lines and bands of several key sp…