The composition of liquid methane–nitrogen aerosols in Titan’s lower atmosphere from Monte Carlo simulations

Firanescu, George; Luckhaus, David; Patey, G. N.; Atreya, S. K.; Signorell, Ruth

doi:10.1016/j.icarus.2011.01.021

Cited by 13 publications

(7 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effective loss tangent of nitrogen dissolved in alkanes, which will be~20% by volume [Firanescu et al, 2011] of the liquid if the major component is methane alone, has not been measured directly. However, liquid Nitrogen at 77 K (in contrast with Ligeia Mare at 90-94 K) has a loss tangent reported to be 5.2 ± 1.4 × 10 À5 , at 15 GHz [Smith et al, 1990], close to that of methane, and so we use this as a proxy until more data are available.…”

Section: Results and Analysismentioning

confidence: 99%

“…While near-infrared spectra confirm the presence of liquid ethane in Ontario Lacus [Brown et al, 2008], the methane-rich atmosphere frustrates remote estimates of liquid methane abundance by spectral absorption features. Rainfall on Titan is thought to consist primarily of liquid methane [Niemann et al, 2005]; such droplets would contain roughly 20% dissolved nitrogen [Lunine et al, 1983;Battino et al, 1984;Thompson, 1985;Lorenz, 1993;Graves et al, 2008;Firanescu et al, 2011] and lesser quantities of other materials, including ethane [Dalba et al, 2012] and possibly propane. Without other processes, surface liquids might be expected to be dominated by a binary mixture of methane and nitrogen.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Laboratory measurements of cryogenic liquid alkane microwave absorptivity and implications for the composition of Ligeia Mare, Titan

Mitchell

Barmatz

Jamieson

et al. 2015

Geophysical Research Letters

View full text Add to dashboard Cite

The complex dielectric constants of liquids methane and ethane were measured at 90 K and 14.1 GHz, close to the frequency of the Cassini RADAR. The liquid ethane loss tangent is far greater than that of liquid methane, facilitating discrimination by remote sensing. The results suggest a methane-dominated composition for the northern sea, Ligeia Mare, on the basis of a recent loss tangent determination using Cassini RADAR altimetry. This contrasts a previous far higher loss tangent for the southern lake, Ontario Lacus, which is inconsistent with simple mixtures of methane and ethane. The apparent nonequilibrium methane-to-ethane ratio of Ligeia Mare can be explained by poor admixture of periodically cycled methane with a deeper ethane-rich alkanofer system, consistent with obliquity-driven volatile cycling, sequestration of ethane from the hydrocarbon cycle by incorporation into crustal clathrate hydrates, or periodic flushing of Ligeia Mare into adjacent Kraken Mare by fresh rainfall.

show abstract

Section: Results and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Laboratory measurements of cryogenic liquid alkane microwave absorptivity and implications for the composition of Ligeia Mare, Titan

Mitchell

Barmatz

Jamieson

et al. 2015

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…Nitrogen and methane are the a) Electronic mail: robert.hellmann@uni-rostock.de main constituents of Titan's atmosphere, and the dynamic interaction between the lakes and the atmosphere is currently of special interest. [12][13][14][15][16] Natural gas, which is predominantly methane, also contains nitrogen, which not only reduces its calorific value, but plays an important part in the liquefaction process.…”

Section: Introductionmentioning

confidence: 99%

Intermolecular potential energy surface and thermophysical properties of the CH4–N2 system

Hellmann

Bich

Vogel

et al. 2014

The Journal of Chemical Physics

133

View full text Add to dashboard Cite

Articles you may be interested in Ab initio potential energy surface for methane and carbon dioxide and application to vapor-liquid coexistence J. Chem. Phys. 141, 064303 (2014) A five-dimensional potential energy surface (PES) for the interaction of a rigid methane molecule with a rigid nitrogen molecule was determined from quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the CCSD(T) level of theory was utilized to compute a total of 743 points on the PES. The interaction energies were calculated using basis sets of up to quadruple-zeta quality with bond functions and were extrapolated to the complete basis set limit. An analytical site-site potential function with nine sites for methane and five sites for nitrogen was fitted to the interaction energies. The PES was validated by calculating the cross second virial coefficient as well as the shear viscosity and binary diffusion coefficient in the dilute-gas limit for CH 4 -N 2 mixtures. An improved PES was obtained by adjusting a single parameter of the analytical potential function in such a way that quantitative agreement with the most accurate experimental values of the cross second virial coefficient was achieved. The transport property values obtained with the adjusted PES are in good agreement with the best experimental data. © 2014 AIP Publishing LLC.

show abstract

“…The authors concluded that super-cooled CH 4 droplets containing ∼30% ± 7% of N 2 can be formed at the low to mid-level cloud conditions on Titan. The obtained N 2 mole fraction can be explained by a Monte Carlo simulation for which the vapor-liquid equilibration is assumed (Firanescu et al 2011). The N 2 mole fraction obtained by the Monte Carlo method can readily be reproduced by the kinetic approach discussed below.…”

Section: Model Validationmentioning

confidence: 99%

Methane-Nitrogen Binary Nucleation: A New Microphysical Mechanism for Cloud Formation in Titan's Atmosphere

Tsai

Liang

Chen

2012

ApJ

View full text Add to dashboard Cite

It is known that clouds are present in the troposphere of Titan; however, their formation mechanism, particle size, and chemical composition remain poorly understood. In this study, a two-component (CH 4 and N 2 ) bin-microphysics model is developed and applied to simulate cloud formation in the troposphere of Titan. A new process, binary nucleation of particles from CH 4 and N 2 gases, is considered. The model is validated and calibrated by recent laboratory experiments that synthesize particle formation in Titan-like environments. Our model simulations show that cloud layers can be formed at about 20 km with a particle size ranging from one to several hundred μm and number concentration 10 −2 to over 100 cm −3 depending on the strength of the vertical updraft. The particles are formed by binary nucleation and grow via the condensation of both CH 4 and N 2 gases, with their N 2 mole fraction varying from <10% in the nucleation stage to >30% in the condensation growth stage. The locally occurring CH 4 -N 2 binary nucleation mechanism is strong and could potentially be more important than the falling condensation nuclei mechanism assumed in many current models.

show abstract

The composition of liquid methane–nitrogen aerosols in Titan’s lower atmosphere from Monte Carlo simulations

Cited by 13 publications

References 54 publications

Laboratory measurements of cryogenic liquid alkane microwave absorptivity and implications for the composition of Ligeia Mare, Titan

Laboratory measurements of cryogenic liquid alkane microwave absorptivity and implications for the composition of Ligeia Mare, Titan

Intermolecular potential energy surface and thermophysical properties of the CH4–N2 system

Methane-Nitrogen Binary Nucleation: A New Microphysical Mechanism for Cloud Formation in Titan's Atmosphere

Contact Info

Product

Resources

About