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Coupling photochemistry with haze formation in Titan's atmosphere, Part II: Results and validation with Cassini/Huygens data
Coustenis, A.; Lavvas, P. P.; Vardavas, I. M.
The new one-dimensional radiative-convective/photochemical/microphysical model described in Part I is applied to the study of Titan's atmospheric processes that lead to haze formation. Our model generates the haze structure from the gaseous species photochemistry. Model results are presented for the species vertical concentration profiles, haze fo…
A model of Titan's aerosols based on measurements made inside the atmosphere
Tomasko, M. G.; Doose, L.; Engel, S. +5 more
The descent imager/spectral radiometer (DISR) instrument aboard the Huygens probe into the atmosphere of Titan measured the brightness of sunlight using a complement of spectrometers, photometers, and cameras that covered the spectral range from 350 to 1600 nm, looked both upward and downward, and made measurements at altitudes from 150 km to the …
Coupling photochemistry with haze formation in Titan's atmosphere, Part I: Model description
Coustenis, A.; Lavvas, P. P.; Vardavas, I. M.
We introduce a new 1D coupled Radiative/Convective-Photochemical-Microphysical model for a planetary atmosphere and apply it to Titan. The model incorporates detailed radiation transfer calculations for the description of the shortwave and longwave fluxes which provide the vertical structure of the radiation field and temperature profile. These ar…
Fluvial channels on Titan: Initial Cassini RADAR observations
Cassini RADAR Team; Kirk, Randolph L.; Lorenz, Ralph D. +13 more
Cassini radar images show a variety of fluvial channels on Titan's surface, often several hundreds of kilometers in length. Some (predominantly at low- and mid-latitude) are radar-bright and braided, resembling desert washes where fines have been removed by energetic surface liquid flow, presumably from methane rainstorms. Others (predominantly at…
Ion and neutral sources and sinks within Saturn's inner magnetosphere: Cassini results
Thomsen, M. F.; Johnson, R. E.; Hartle, R. E. +16 more
Using ion-electron fluid parameters derived from Cassini Plasma Spectrometer (CAPS) observations within Saturn's inner magnetosphere as presented in Sittler et al. [2006a. Cassini observations of Saturn's inner plasmasphere: Saturn orbit insertion results. Planet. Space Sci., 54, 1197-1210], one can estimate the ion total flux tube content, N…
Mars Express and Venus Express multi-point observations of geoeffective solar flare events in December 2006
Coates, A. J.; Kallio, E.; Fedorov, A. +50 more
In December 2006, a single active region produced a series of proton solar flares, with X-ray class up to the X9.0 level, starting on 5 December 2006 at 10:35 UT. A feature of this X9.0 flare is that associated MeV particles were observed at Venus and Mars by Venus Express (VEX) and Mars Express (MEX), which were ∼80° and ∼125° east of the flare s…
Methane in Martian atmosphere: Average spatial, diurnal, and seasonal behaviour
Geminale, A.; Formisano, V.; Giuranna, M.
A large number of spectra measured by the planetary Fourier spectrometer aboard the European Mars Express mission have been studied to identify the average properties of methane in the Martian atmosphere. Using the line at 3018 cm -1, we have studied the seasonal, diurnal, and spatial variations of methane through the analysis of large …
Derivation of density and temperature from the Cassini Huygens CAPS electron spectrometer
André, N.; Lewis, G. R.; Coates, A. J. +4 more
In this paper we present two methods to derive electron fluid parameters from the CAPS-ELS spectrometer on board the Cassini spacecraft currently in orbit around Saturn. In the first part of the paper we give a basic overview of the instrument and describe the challenges inherent in the derivation of density and temperature values using these tech…
Initial Venus Express magnetic field observations of the Venus bow shock location at solar minimum
Barabash, S.; Russell, C. T.; Zhang, T. L. +10 more
In this study, magnetic field measurements obtained by the Venus Express spacecraft are used to determine the bow shock position at solar minimum. The best fit of bow shock location from solar zenith angle 20-120° gives a terminator bow shock location of 2.14 RV (1 RV=6052 km) which is 1600 km closer to Venus than the 2.40 R<…
Location of the bow shock and ion composition boundaries at Venus—initial determinations from Venus Express ASPERA-4
Coates, A. J.; Kallio, E.; Fedorov, A. +52 more
For the first time since 1992 when the Pioneer Venus Orbiter (PVO) ceased to operate, there is again a plasma instrument in orbit around Venus, namely the ASPERA-4 flown on Venus Express (inserted into an elliptical polar orbit about the planet on April 11, 2006). In this paper we report on measurements made by the ion and electron sensors of ASPE…