Search Publications
Vertical temperature profiles in the Venus mesosphere obtained by two retrieval methods from the VIRTIS-VEX observations
Banaszkiewicz, Marek; Piccioni, Giuseppe; Wolkenberg, Paulina
We present vertical temperature profiles derived by two different retrieval methods from nighttime radiation measurements performed by VIRTIS(M)-VEx (Visible and Infrared Thermal Imaging Spectrometer, M channel-Venus Express). The Bayesian approach to the optimal estimation method and the relaxation method are applied in this study. This is a firs…
The CO2 absorption spectrum in the 2.3 µm transparency window by high sensitivity CRDS: (II) Self-absorption continuum
Campargue, A.; Vasilchenko, S.; Mondelain, D. +2 more
The CO2 absorption continuum near 2.3 µm is determined for a series of sub atmospheric pressures (250-750 Torr) by high sensitivity Cavity Ring Down Spectroscopy. An experimental procedure consisting in injecting successively a gas flow of CO2 and synthetic air, keeping constant the gas pressure in the CRDS cell, has be…
Line strengths of rovibrational and rotational transitions in the X2 Π ground state of OH
Li, Gang; Afşar, Melike; Sneden, Christopher +4 more
A new line list including positions and absolute transition strengths (in the form of Einstein A values and oscillator strengths) has been produced for the OH ground X2 Π state rovibrational (Meinel system) and pure rotational transitions. All possible transitions are included with v‧ and v ″ up to 13, and J up to between 9.5…
The CO2 absorption spectrum in the 2.3 µm transparency window by high sensitivity CRDS: (I) Rovibrational lines
Campargue, A.; Perevalov, V. I.; Tashkun, S. A. +5 more
The absorption of carbon dioxide is very weak near 2.3 µm which makes this transparency window of particular interest for the study of Venus' lower atmosphere. As a consequence of the weakness of the transitions located in this region, previous experimental data are very scarce and spectroscopic databases provide calculated line lists which …
FTIR-based measurements of self-broadening and self-shift coefficients as well as line strength in the first overtone band of HCl at 1.76 µM
Li, Gang; Serdyukov, Anton; Gisi, Michael +2 more
FTIR spectra of the 2-0 band of HCl have been measured in the 5300-5900 cm-1 spectral region at 15 different pressures (0.05-2.5 bar) and at a spectral resolution of 0.07 cm-1. For the first time, reliable and consistent self-induced broadening and shift coefficients for the complete HCl 2-0 band have been reported. Line inte…
High pressure Cavity Ring Down Spectroscopy: Application to the absorption continuum of CO2 near 1.7 µm
Campargue, A.; Tran, H.; Mondelain, D. +1 more
A Cavity Ring Down Spectrometer has been developed for high sensitivity absorption spectroscopy in the near infrared at pressure up to 10 bar. In order to strictly avoid perturbations of the optical alignment by pressure forces, the pre-aligned CRDS cavity is inserted inside the high pressure cell. The stability of the spectra baseline has been va…
Infrared absorption by pure CO2 near 3340 cm-1: Measurements and analysis of collisional coefficients and line-mixing effects at subatmospheric pressures
Daneshvar, L.; Földes, T.; Buldyreva, J. +1 more
High resolution Fourier transform spectra of the 21102-00001 band of 12C16O2 near 3340 cm-1 have been recorded and analyzed to extract isolated-line intensities and collisional parameters, and first-order line-mixing coefficients. Voigt, hard-collision Rautian and Sobel'man, and quadratic-speed-dependent…
MSR, a multi-spectrum retrieval technique for spatially-temporally correlated or common Venus surface and atmosphere parameters
Kappel, David
A common way to regularize mathematical ill-posed retrieval problems in atmospheric remote sensing is the incorporation of single-spectrum Bayesian a priori mean values and standard deviations for the parameters to be retrieved, along with measurement and simulation error information. This decreases the probability to obtain unlikely parameter val…
Carbon dioxide absorption at high densities in the 1.18 µm nightside transparency window of Venus
Piccioni, Giuseppe; Snels, Marcel; Stefani, Stefania +1 more
The attenuation of carbon dioxide at pressures between 1 and 38 bar has been measured from 1179.5 to 1182.7 nm at room temperature (293 K) by using a cavity ring down spectrometer. The densities used in the experiment correspond with the densities in the Venus atmosphere from about 50 km down to the surface, although the experimental temperature i…
Experimental CO2 absorption coefficients at high pressure and high temperature
Piccioni, Giuseppe; Adriani, Alberto; Grassi, Davide +2 more
Here we present a laboratory study of CO2 absorption spectra, obtained at high temperatures and pressures, similar to those encountered in the Venusian atmosphere. These spectra have been recorded using a Fourier Transform InfraRed (FT-IR) spectrometer , which is equipped to operate from 800 to 30,000 cm-1 (0.33-12.5 µm…