Search Publications
Mid-infrared spectroscopy of Uranus from the Spitzer infrared spectrometer: 2. Determination of the mean composition of the upper troposphere and stratosphere
Fletcher, Leigh N.; Moses, Julianne I.; Line, Michael R. +7 more
Mid-infrared spectral observations Uranus acquired with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope are used to determine the abundances of C2H2, C2H6, CH3C2H, C4H2, CO2, and tentatively CH3 on Uranus at the time of the …
Cassini observations reveal a regime of zonostrophic macroturbulence on Jupiter
Read, Peter L.; Young, Roland M. B.; Armstrong, David +4 more
In December 2000, the Cassini fly-by near Jupiter delivered high-resolution images of Jupiter’s clouds over the entire planet in a band between 50°N and 50°S. Three daily-averaged two-dimensional velocity snapshots extracted from these images are used to perform spectral analysis of jovian atmospheric macroturbulence. A similar analysis is also pe…
Neptune at summer solstice: Zonal mean temperatures from ground-based observations, 2003-2007
de Pater, Imke; Fletcher, Leigh N.; Irwin, Patrick G. J. +3 more
Imaging and spectroscopy of Neptune's thermal infrared emission from Keck/LWS (2003), Gemini-N/MICHELLE (2005); VLT/VISIR (2006) and Gemini-S/TReCS (2007) is used to assess seasonal changes in Neptune's zonal mean temperatures between Voyager-2 observations (1989, heliocentric longitude Ls = 236 °) and southern summer solstice (2005, L<…
The dayside ionospheres of Mars and Venus: Comparing a one-dimensional photochemical model with MaRS (Mars Express) and VeRa (Venus Express) observations
González-Galindo, F.; Tellmann, Silvia; Tyler, G. Leonard +8 more
The electron density distributions of the lower ionospheres of Mars and Venus are mainly dependent on the solar X-ray and EUV flux and the solar zenith angle. The influence of an increasing solar flux is clearly seen in the increase of the observed peak electron density and total electron content (TEC) of the main ionospheric layers. The model “Io…
Formation of lobate debris aprons on Mars: Assessment of regional ice sheet collapse and debris-cover armoring
Head, James W.; Fastook, James L.; Marchant, David R.
Lobate debris aprons (LDA) are lobate-shaped aprons surrounding scarps and isolated massifs that are concentrated in the vicinity of the northern Dichotomy Boundary on Mars. LDAs have been interpreted as (1) ice-cemented talus aprons undergoing viscous flow, (2) local debris-covered alpine-like glaciers, or (3) remnants of the collapse of a region…
Global climate modeling of Saturn’s atmosphere. Part I: Evaluation of the radiative transfer model
Forget, F.; Millour, E.; Spiga, A. +8 more
We have developed and optimized a seasonal, radiative-convective model of Saturn’s upper troposphere and stratosphere. It is used to investigate Saturn’s radiatively-forced thermal structure between 3 and 10-6 bar, and is intended to be included in a Saturn global climate model (GCM), currently under development. The main elements of th…
High latitude gravity waves at the Venus cloud tops as observed by the Venus Monitoring Camera on board Venus Express
Markiewicz, W. J.; Titov, D. V.; Peralta, J. +4 more
High resolution images of Venus Northern hemisphere obtained with the Venus Monitoring Camera (VMC/VEx) allow studying small-scale dynamical phenomena at the cloud tops (∼62-70 km altitude) including features like wave trains. A systematic visual search of these waves was performed; more than 1500 orbits were analyzed and wave patterns were observ…
The distribution of methane in Titan’s stratosphere from Cassini/CIRS observations
Lellouch, E.; Flasar, F. M.; Bézard, B. +5 more
Cassini/CIRS spectra in the far- and mid-infrared region are used to determine the abundance of methane in Titan's lower stratosphere and investigate its distribution with latitude. The CIRS spectra include emission from both the CH4 ν4 band at 7.7 µm and pure rotational lines longwards of 50 µm, which show differ…
Inverse insolation dependence of Venus' cloud-level convection
Imamura, Takeshi; Ando, Hiroki; Sugimoto, Norihiko +4 more
It is generally accepted that convection in planetary atmospheres is enhanced in low latitudes and in the daytime where incoming solar radiation is intense. Here we demonstrate, using a local convection model, that this tendency is reversed for Venus' cloud-level convection, which is driven by heating of the cloud base by upwelling infrared radiat…
Aromatic and aliphatic organic materials on Iapetus: Analysis of Cassini VIMS data
Clark, Roger N.; Cruikshank, Dale P.; Pendleton, Yvonne J. +1 more
We present a quantitative analysis of the hydrocarbon and other organic molecular inventory as a component of the low-albedo material of Saturn’s satellite Iapetus, based on a revision of the calibration of the Cassini VIMS instrument. Our study uses hyperspectral data from a mosaic of Iapetus’ surface (Pinilla-Alonso, N., Roush, T.L., Marzo, G.A.…