Search Publications
Variations of sulphur dioxide at the cloud top of Venus's dynamic atmosphere
Montmessin, Franck; Bertaux, Jean-Loup; Marcq, Emmanuel +1 more
Sulphur dioxide is a million times more abundant in the atmosphere of Venus than that of Earth, possibly as a result of volcanism on Venus within the past billion years. A tenfold decrease in sulphur dioxide column density above Venus's clouds measured by the Pioneer Venus spacecraft during the 1970s and 1980s has been interpreted as decline follo…
Cloud level winds from the Venus Express Monitoring Camera imaging
Roatsch, Th.; Ignatiev, N. I.; Markiewicz, W. J. +7 more
Six years of continuous monitoring of Venus by European Space Agency’s Venus Express orbiter provides an opportunity to study dynamics of the atmosphere our neighbor planet. Venus Monitoring Camera (VMC) on-board the orbiter has acquired the longest and the most complete so far set of ultra violet images of Venus. These images enable a study the c…
Long-term variation in the cloud-tracked zonal velocities at the cloud top of Venus deduced from Venus Express VMC images
Futaana, Yoshifumi; Imamura, Takeshi; Kouyama, Toru +2 more
We present observational evidence of the variation of the cloud-tracked zonal velocity by ~20 m s-1 with a timescale of a few hundred days in the southern low latitude region based on an analysis of cloud images taken by the Venus Monitoring Camera on board Venus Express. A spectral analysis suggests that the variation has a periodicity…
A global multispecies single-fluid MHD study of the plasma interaction around Venus
Russell, C. T.; Wei, H. Y.; Toth, G. +3 more
This paper reports a new global multispecies single-fluid MHD model that was recently developed for Venus. This model is similar to the numerical model that has been successfully applied to Mars. Mass densities of proton and three important ionospheric ion species (O+, O2+, and CO2+) are self-…
Observations of D/H ratios in H2O, HCl, and HF on Venus and new DCl and DF line strengths
Li, G.; Belyaev, D. A.; Krasnopolsky, V. A. +2 more
Intensities of the spectral lines in the fundamental bands of D35Cl and DF were calculated using the semi-empirical dipole moment functions derived from the most accurate and precise measurements of intensities of the ro-vibrational lines of H35Cl and HF. Values obtained in this way for the deuterated species are superior to …
Hemispheric asymmetries of the Venus plasma environment
Kallio, E.; Jarvinen, R.; Dyadechkin, S.
We study the Venus-solar wind interaction and the hemispheric asymmetries of the Venus plasma environment in the global HYB-Venus hybrid simulation. We concentrate especially on the role of the flow-aligned interplanetary magnetic field (IMF) component (i.e., the Parker spiral angle or the IMF cone angle) and analyze the dawn-dusk and Esw
Plasma in the near Venus tail: Venus Express observations
Fedorov, A.; Barabash, S.; Lundin, R. +5 more
Although Venus has no global intrinsic magnetic fields, it possesses a long magnetotail of induced origin. The topology of the tail is determined by the interplanetary magnetic field orientation. We present recent plasma and magnetic field observations in the near Venus tail (X≥-3RV) made by the Venus Express spacecraft. We show that io…
Self-consistent retrieval of temperature profiles and cloud structure in the northern hemisphere of Venus using VIRTIS/VEX and PMV/VENERA-15 radiation measurements
Kappel, D.; Arnold, G.; Haus, R.
Improved radiative transfer simulation and multi-window retrieval procedures (MWR) are described that are applied to investigate thermal structure and cloud features in the nightside atmosphere of Venus over the northern hemisphere. Comparative analyses of spectroscopic data, which were recorded independently in different parts of the infrared spe…
HDO and SO2 thermal mapping on Venus. II. The SO2 spatial distribution above and within the clouds
Encrenaz, T.; Atreya, S. K.; Bézard, B. +6 more
Sulfur dioxide and water vapor, two key species of Venus photochemistry, are known to exhibit significant spatial and temporal variations above the cloud top. In particular, ground-based thermal imaging spectroscopy at high spectral resolution, achieved on Venus in January 2012, has shown evidence for strong SO2 variations on timescales…
Electron density distribution and solar plasma correction of radio signals using MGS, MEX, and VEX spacecraft navigation data and its application to planetary ephemerides
Issautier, K.; Laskar, J.; Fienga, A. +3 more
The Mars Global Surveyor (MGS), Mars Express (MEX), and Venus Express (VEX) experienced several superior solar conjunctions. These conjunctions cause severe degradations of radio signals when the line of sight between the Earth and the spacecraft passes near to the solar corona region. The primary objective of this work is to deduce a solar corona…