Search Publications
Generic Magnetic Field Intensity Profiles of Interplanetary Coronal Mass Ejections at Mercury, Venus, and Earth From Superposed Epoch Analyses
Lugaz, Noé; Möstl, Christian; Janvier, Miho +8 more
We study interplanetary coronal mass ejections (ICMEs) measured by probes at different heliocentric distances (0.3-1 AU) to investigate the propagation of ICMEs in the inner heliosphere and determine how the generic features of ICMEs change with heliospheric distance. Using data from the MErcury Surface, Space ENvironment, GEochemistry, and Rangin…
Long-term Variations of Venus’s 365 nm Albedo Observed by Venus Express, Akatsuki, MESSENGER, and the Hubble Space Telescope
Marcq, Emmanuel; Imamura, Takeshi; Titov, Dmitrij V. +16 more
An unknown absorber near the cloud-top level of Venus generates a broad absorption feature from the ultraviolet (UV) to visible, peaking around 360 nm, and therefore plays a critical role in the solar energy absorption. We present a quantitative study of the variability of the cloud albedo at 365 nm and its impact on Venus’s solar heating rates ba…
HDO and SO2 thermal mapping on Venus. IV. Statistical analysis of the SO2 plumes
Encrenaz, T.; Atreya, S. K.; Bézard, B. +10 more
Since January 2012 we have been monitoring the behavior of sulfur dioxide and water on Venus, using the Texas Echelon Cross-Echelle Spectrograph (TEXES) imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF, Mauna Kea Observatory). We present here the observations obtained between January 2016 and September 2018. As in the case of our…
Effects of the solar wind and the solar EUV flux on O+ escape rates from Venus
Fedorov, A.; Barabash, S.; Futaana, Y. +4 more
We investigate dependences of O+ escape rates from Venus both on the solar wind and the solar extreme ultraviolet (EUV) flux by using the 8.5-year dataset (May 2006 to December 2014) of the Ion Mass Analyzer and the magnetometer aboard Venus Express. We examine the O+ escape rates for 8 different conditions depending on the s…
Observations of the Venus Dramatic Response to an Extremely Strong Interplanetary Coronal Mass Ejection
Xu, Qi; Zhang, Tielong; Rong, Zhaojin +4 more
On 2011 November 5, Venus Express observed the impact of an extremely strong interplanetary coronal mass ejection (ICME) on Venus. As a result, the Venusian induced magnetosphere dramatically fluctuated during the ICME passage: the bow shock was compressed and broadened by the sheath and the body of the ICME, respectively; an atypically strong mag…
Venus Express radio occultation observed by PRIDE
Wang, W.; Zheng, W.; Bocanegra-Bahamón, T. M. +18 more
Context. Radio occultation is a technique used to study planetary atmospheres by means of the refraction and absorption of a spacecraft carrier signal through the atmosphere of the celestial body of interest, as detected from a ground station on Earth. This technique is usually employed by the deep space tracking and communication facilities (e.g.…
Equatorial Kelvin-like waves on slowly rotating and/or small-sized spheres: Application to Venus and Titan
Yamamoto, Masaru
Equatorial Kelvin waves, which have been observed in planetary fluids, produce superrotation and climatological variability. Although the meridional flow component is zero on Earth's beta-plane in the absence of background basic flow, it cannot be neglected on spheres in some planetary fluids when the Lamb parameter is small. For a vertically prop…
Proton Temperature Anisotropies in the Plasma Environment of Venus
Futaana, Y.; Zhang, T. L.; Nilsson, H. +5 more
Velocity distribution functions (VDFs) are a key to understanding the interplay between particles and waves in a plasma. Any deviation from an isotropic Maxwellian distribution may be unstable and result in wave generation. Using data from the ion mass spectrometer IMA (Ion Mass Analyzer) and the magnetometer (MAG) onboard Venus Express, we study …
Morphology and Dynamics of Venus's Middle Clouds With Akatsuki/IR1
Hueso, R.; Sánchez-Lavega, A.; Kardasis, E. +8 more
The Venusian atmosphere is covered by clouds with superrotating winds whose accelerating mechanism is still not well understood. The fastest winds, occurring at the cloud tops (∼70-km height), have been studied for decades, thanks to their visual contrast in dayside ultraviolet images. The middle clouds (∼50-55 km) can be observed at near-infrared…
Validation of the IPSL Venus GCM Thermal Structure with Venus Express Data
Piccioni, Giuseppe; Tellmann, Silvia; Lebonnois, Sebastien +4 more
General circulation models (GCMs) are valuable instruments to understand the most peculiar features in the atmospheres of planets and the mechanisms behind their dynamics. Venus makes no exception and it has been extensively studied thanks to GCMs. Here we validate the current version of the Institut Pierre Simon Laplace (IPSL) Venus GCM, by means…