Methods for the analysis of data from the Planetary Fourier Spectrometer on the Mars Express Mission

Grassi, D.; Ignatiev, N.; Zasova, L. V.; Maturilli, Alessandro; Formisano, V.; Bianchini, G.; Giuranna, M.

doi:10.1016/j.pss.2005.01.006

Cited by 54 publications

(44 citation statements)

References 35 publications

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“…Adopting the very general formalism of Bayesian analysis, an algorithm for the scientific analysis of individual calibrated PFS measurements has been developed, allowing the simultaneous retrieval of the above mentioned parameters. A full description of the adopted method can be found in Grassi et al (2005). The cases presented in this study were carefully selected imposing a value of chi-square test close to 1 in the selected spectral range of 400-800 cm −1 .…”

Section: Data Set and Treatmentmentioning

confidence: 99%

“…Black curves: single spectra measured by PFS. Colored curves: synthetic spectra computed by the algorithm for the scientific analysis of individual calibrated PFS measurements, developed by Grassi et al (2005). Black arrows indicate the CO 2 Q-branches.…”

Section: Data Set and Treatmentmentioning

confidence: 99%

“…The black area is where the atmospheric temperature, at a given altitude, goes below the CO 2 condensation temperature at the same altitude. Grassi et al (2005), allows, among other things, the simultaneous retrieval of surface temperature, integrated content of water ice and dust suspended in the atmosphere, and, most important for the issue we want to address, the air thermal fields up to an altitude of about 50 km. By comparing the measured vertical temperature profiles with the CO 2 condensation temperature at different altitudes we can establish if, where and at which altitudes CO 2 snow falls may be allowed.…”

Section: Ls = 0 • -25 • : the Early-fall South Polar Capmentioning

confidence: 99%

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PFS/MEX observations of the condensing CO2 south polar cap of Mars

Giuranna¹,

Grassi²,

Formisano³

et al. 2008

Icarus

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The condensing CO 2 south polar cap of Mars and the mechanisms of the CO 2 ice accumulation have been studied through the analysis of spectra acquired by the Planetary Fourier Spectrometer (PFS) during the first two years of ESA's Mars Express (MEX) mission. This dataset spans more than half a martian year, from Ls ∼ 330 • to Ls ∼ 194 • , and includes the southern fall season which is found to be extremely important for the study of the residual south polar cap asymmetry. The cap expands symmetrically and with constant speed during the fall season. The maximum extension occurs sometime in the 80 • -90 • Ls range, when the cap edges are as low as −40 • latitude. Inside Hellas and Argyre basins, frost can be stable at lower latitudes due to the higher pressure values, causing the seasonal cap to be asymmetric. Within the seasonal range considered in this paper, the cap edge recession rate is approximately half the rate at which the cap edge expanded. The longitudinal asymmetries reduce during the cap retreat, and disappear around Ls ∼ 145 • . Two different mechanisms are responsible for CO 2 ice accumulation during the fall season, especially in the 50 • -70 • Ls range. Here, CO 2 condensation in the atmosphere, and thus precipitation, is allowed exclusively in the western hemisphere, and particularly in the longitudinal corridor of the perennial cap. In the eastern hemisphere, the cap consists mainly of CO 2 frost deposits, as a consequence of direct vapor deposition. The differences in the nature of the surface ice deposits are the main cause for the residual south polar cap asymmetry. Results from selected PFS orbits have also been compared with the results provided by the martian general circulation model (GCM) of the Laboratoire de Météorologie dynamique (LMD) in Paris, with the aim of putting the observations in the context of the global circulation. This first attempt of cross-validation between PFS measurements and the LMD GCM on the one hand confirms the interpretation of the observations, and on the other hand shows that the climate modeling during the southern polar night on Mars is extremely sensitive to the dynamical forcing.

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Section: Data Set and Treatmentmentioning

confidence: 99%

Section: Data Set and Treatmentmentioning

confidence: 99%

Section: Ls = 0 • -25 • : the Early-fall South Polar Capmentioning

confidence: 99%

See 1 more Smart Citation

PFS/MEX observations of the condensing CO2 south polar cap of Mars

Giuranna¹,

Grassi²,

Formisano³

et al. 2008

Icarus

Self Cite

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“…The CO 2 isotopic bands can vary in intensity, depending on the local climate. We reproduced this behavior by using a radiative transfer model (Grassi et al, 2005), obtaining a synthetic spectrum (A) that is used to remove the isotopic bands from the observed spectrum (D). In order to account for the real conditions of observation, for each SW average spectrum we used the corresponding LW spectra to extract the actual vertical temperature profiles to be used in the model.…”

Section: [Figure 2]mentioning

confidence: 99%

“…3). Applying the retrieval algorithm described by Grassi et al (2005), we computed the atmospheric dust loading (integrated  at 1100 cm -1 ) from the PFS-LW data. If the 3.9 m band was due to the atmospheric dust, we should expect band depth to increase with increasing  a trend not evident in Fig.…”

Section: [Figure 2]mentioning

confidence: 99%

Evidence for Mg-rich carbonates on Mars from a 3.9 μm absorption feature

Palomba

Zinzi

Cloutis

et al. 2009

Icarus

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Evidence for Mg-rich carbonates on Mars from a 3.9 μm absorption feature, Icarus (2009Icarus ( ), doi: 10.1016Icarus ( /j.icarus.2009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT

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The Venus nighttime atmosphere as observed by the VIRTIS‐M instrument. Average fields from the complete infrared data set

et al. 2014

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We present and discuss here the average fields of the Venus atmosphere derived from the nighttime observations in the 1960-2350 cm À1 spectral range by the VIRTIS-M instrument on board the Venus Express satellite. These fields include: (a) the air temperatures in the 1-100 mbar pressure range (~85-65 km above the surface), (b) the altitude of the clouds top, and (c) the average CO mixing ratio. A new retrieval code based on the Bayesian formalism has been developed and validated on simulated observations, to statistically assess the retrieval capabilities of the scheme once applied to the VIRTIS data. The same code has then been used to process the entire VIRTIS-M data set. Resulting individual retrievals have been binned on the basis of local time and latitude, to create average fields. Air temperature fields confirm the general trends previously reported in Grassi et al. (2010), using a simplified retrieval scheme and a more limited data set. At the lowest altitudes probed by VIRTIS (~65 km), air temperatures are strongly asymmetric around midnight, with a pronounced minima at 3LT, 70°S. Moving to higher levels, the air temperatures first become more uniform in local time (~75 km), then display a colder region on the evening side at the upper boundary of VIRTIS sensitivity range (~80 km). As already shown by Ignatiev et al. (2008) for the dayside, the cloud effective altitude increases monotonically from the south pole to the equator. However, the variations observed in night data are consistent with an overall variation of just 1 km, much smaller than the 4 km reported for the dayside. The cloud altitudes appear slightly higher on the evening side. Both observations are consistent with a less vigorous meridional circulation on the nightside of the planet. Carbon monoxide is not strongly constrained by the VIRTIS-M data. However, average fields present a clear maximum of 80 ppm around 60°S, well above the retrieval uncertainty. Once the intrinsic low sensitivity of VIRTIS data in the region of cold collar is kept in mind, this datum is consistent with a [CO] enrichment toward the poles driven by meridional circulation.

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Methods for the analysis of data from the Planetary Fourier Spectrometer on the Mars Express Mission

Cited by 54 publications

References 35 publications

PFS/MEX observations of the condensing CO2 south polar cap of Mars

PFS/MEX observations of the condensing CO2 south polar cap of Mars

Evidence for Mg-rich carbonates on Mars from a 3.9 μm absorption feature

The Venus nighttime atmosphere as observed by the VIRTIS‐M instrument. Average fields from the complete infrared data set

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