Search Publications
Ion Energization and Escape on Mars and Venus
Fedorov, A.; Lundin, R.; Dubinin, E. +4 more
Mars and Venus do not have a global magnetic field and as a result solar wind interacts directly with their ionospheres and upper atmospheres. Neutral atoms ionized by solar UV, charge exchange and electron impact, are extracted and scavenged by solar wind providing a significant loss of planetary volatiles. There are different channels and routes…
The Induced Magnetospheres of Mars, Venus, and Titan
Szego, K.; Fraenz, M.; Edberg, N. +4 more
This article summarizes and aims at comparing the main features of the induced magnetospheres of Mars, Venus and Titan. All three objects form a well-defined induced magnetosphere (IM) and magnetotail as a consequence of the interaction of an external wind of plasma with the ionosphere and the exosphere of these objects. In all three, photoionizat…
The 1.10- and 1.18-µm nightside windows of Venus observed by SPICAV-IR aboard Venus Express
Bertaux, Jean-Loup; Korablev, Oleg; Bézard, Bruno +2 more
Observations of the 1.10- and 1.18-µm nightside windows by the SPICAV-IR instrument aboard Venus Express were analyzed to characterize the various sources of gaseous opacity and determine the H 2O mole fraction in the lower atmosphere of Venus. We showed that the line profile model of Afanasenko and Rodin (Afanasenko, T.S., Rodin,…
Ion Acceleration and Outflow from Mars and Venus: An Overview
Lundin, Rickard
Solar wind forcing of Mars and Venus results in outflow and escape of ionospheric ions. Observations show that the replenishment of ionospheric ions starts in the dayside at low altitudes (≈300-800 km), ions moving at a low velocity (5-10 km/s) in the direction of the external/ magnetosheath flow. At high altitudes, in the inner magnetosheath and …
Measurements of the ion escape rates from Venus for solar minimum
Fedorov, A.; Barabash, S.; Lundin, R. +4 more
We report the first direct measurements of the Venusian atmospheric erosion rate due to the interaction with the solar wind. The erosion through the ion escape is determined during the period of the minimum solar activity from 24 May 2006 to 12 December 2007. The ion fluxes are measured in the energy range 10 eV to 25 keV by an ion mass spectromet…
An investigation of the SO 2 content of the venusian mesosphere using SPICAV-UV in nadir mode
Montmessin, Franck; Bertaux, Jean-Loup; Marcq, Emmanuel +4 more
Using the SPICAV-UV spectrometer aboard Venus Express in nadir mode, we were able to derive spectral radiance factors in the middle atmosphere of Venus in the 170-320 nm range at a spectral resolution of R ≃ 200 during 2006 and 2007 in the northern hemisphere. By comparison with a radiative transfer model of the upper atmosphere of Venus, we could…
Arrival Time Calculation for Interplanetary Coronal Mass Ejections with Circular Fronts and Application to STEREO Observations of the 2009 February 13 Eruption
Luhmann, J. G.; Zhang, T. L.; Möstl, C. +11 more
One of the goals of the NASA Solar TErestrial RElations Observatory (STEREO) mission is to study the feasibility of forecasting the direction, arrival time, and internal structure of solar coronal mass ejections (CMEs) from a vantage point outside the Sun-Earth line. Through a case study, we discuss the arrival time calculation of interplanetary C…
Ionospheric photoelectrons: Comparing Venus, Earth, Mars and Titan
Coates, A. J.; Barabash, S.; Lundin, R. +6 more
The sunlit portion of planetary ionospheres is sustained by photoionization. This was first confirmed using measurements and modelling at Earth, but recently the Mars Express, Venus Express and Cassini-Huygens missions have revealed the importance of this process at Mars, Venus and Titan, respectively. The primary neutral atmospheric constituents …
Atmospheric erosion of Venus during stormy space weather
Fedorov, A.; Barabash, S.; Futaana, Y. +9 more
We study atmospheric escape from Venus during solar minimum conditions when 147 corotating interaction regions (CIRs) and interplanetary coronal mass ejections (ICMEs) combined impact on the planet. This is the largest study to date of the effects of stormy space weather on Venus and we show for the first time statistically that the atmosphere of …
A layer of ozone detected in the nightside upper atmosphere of Venus
Vandaele, A. C.; Montmessin, F.; Fedorova, A. +7 more
To date, ozone has only been identified in the atmospheres of Earth and Mars. This study reports the first detection of ozone in the atmosphere of Venus by the SPICAV ultraviolet instrument onboard the Venus Express spacecraft. Venusian ozone is characterized by a vertically confined and horizontally variable layer residing in the thermosphere at …