Search Publications
Modeling the distribution of H2O and HDO in the upper atmosphere of Venus
Liang, Mao-Chang; Yung, Yuk L.
The chemical and dynamical processes in the upper atmosphere of Venus are poorly known. Recently obtained vertical profiles of trace species from the Venus Express mission, such as HCl, H2O, and HDO, provide new information to constrain these processes. Here, we simulate these profiles, using the model we have developed and described in…
Processes of auroral thermal structure at Jupiter: Analysis of multispectral temperature observations with the Jupiter Thermosphere General Circulation Model
Waite, J. H.; Gladstone, G. R.; Bougher, S. W. +1 more
We use our three-dimensional Jupiter Thermosphere General Circulation Model (JTGCM) to quantify thermal processes that take place in the auroral thermosphere. These processes tend to control the thermal budget in the Jovian ovals and polar caps and maintain thermospheric temperatures consistent with those derived from multispectral observations of…
Multivariate analysis of Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) Venus Express nightside and limb observations
Erard, S.; Drossart, P.; Piccioni, G.
Spectral signatures measured by Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on the nightside and at the limb of Venus are analyzed with Independent Component Analysis. A methodology has been set up to minimize instrumental effects and to interpret the results on the basis of studies of the most common situations in the data set. The…
Venus Express bistatic radar: High-elevation anomalous reflectivity
Tyler, G. Leonard; Pätzold, Martin; Häusler, Bernd +2 more
Magellan (MGN) bistatic radar observations in 1994 confirmed earlier Pioneer Venus reports of unusual Venus surface reflectivity and emissivity at elevations above 6054 km radius. They also revealed that the anomalous values of surface dielectric constant $\varepsilon$ near Cleopatra Patera included a large imaginary component ($\varepsilon$ ≈ -i …
Cloud structure in Venus middle-to-lower atmosphere as inferred from VEX/VIRTIS 1.74 µm data
Drossart, P.; Piccioni, G.; Imamura, T. +5 more
We have analyzed 1.74 µm nightside emission of Venus recorded using Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) onboard European Space Agency's (ESA) Venus Express (Orbit 344, 30-31 March 2007). Attention was paid to how infrared radiance, intense at the center of the 1.74 µm “window”, dims at an off-center wavelength (1…
Retrieval of Mars surface physical properties from OMEGA hyperspectral images using regularized sliced inverse regression
Douté, S.; Bernard-Michel, C.; Fauvel, M. +2 more
In this paper, a method based on modeling and statistics is proposed to evaluate the physical properties of surface icy materials on Mars from hyperspectral images collected by the OMEGA instrument aboard the Mars Express spacecraft. The approach is based on the estimation of the functional relationship F between observed spectra and relevant phys…
O+ ion flow below the magnetic barrier at Venus post terminator
Coates, A. J.; Fedorov, A.; Barabash, S. +5 more
Venus forms an obstacle in the streaming solar wind; inside the obstacle boundary (that is below the magnetic barrier) the ions of planetary origin dominate the plasma. The objective of this study is to investigate the properties of the O+ ions inside the obstacle boundary of Venus in the wake; we are especially interested in the charac…
An analysis of VLF electric field spectra measured in Titan's atmosphere by the Huygens probe
Morente, Juan A.; Portí, Jorge A.; Blanchard, Cedric +2 more
A numerical simulation of Titan's electromagnetic cavity in the VLF band is carried out using the Transmission Line Matrix (TLM) method, with the aim of assessing the VLF electric field spectra sent by the Huygens probe. In an Earth-like model, successive peaks would be expected in the spectra, associated with multiple reflections of the electroma…
Correction to “Plasma environment of Venus: Comparison of Venus Express ASPERA-4 measurements with 3-D hybrid simulations”
Barabash, S.; Lundin, R.; Krupp, N. +13 more
Abstract Available from http://www.agu.org
Simultaneous observations of the Martian atmosphere by Planetary Fourier Spectrometer on Mars Express and Miniature Thermal Emission Spectrometer on Mars Exploration Rover
Smith, M.; Grassi, D.; Formisano, V. +3 more
In this study we present temperature profiles in the lower atmosphere of Mars from simultaneous observations performed by the Planetary Fourier Spectrometer (PFS) aboard the Mars Express spacecraft and the Miniature Thermal Emission Spectrometer (Mini-TES) aboard the Mars Exploration Rovers. Thermal infrared spectra were collected in both the upwa…