Thermal convection in the porous methane-soaked regolith in Titan: Finite amplitude convection

• Published in: Icarus (New York, N.Y. 1962) N.Y. 1962), 2012, Vol.217 (1), p.130-143
• Main Authors: Czechowski, Leszek, Kossacki, Konrad J.
• Format: Article
• Language: English
• Subjects: Amplitudes; Astronomy; Cassini mission; Convection; Earth, ocean, space; Exact sciences and technology; Liquids; Mathematical analysis; Mathematical models; Regolith; Regoliths; Satellites, Surfaces; Solar system; Thermal histories; Titan
• ISSN: 0019-1035; 1090-2643
• DOI: 10.1016/j.icarus.2011.10.006

► In some regions of the Saturnian satellite Titan the regoligh is soaked with liquid. ► We found that ‘geothermal’ heat flow could drive thermal convection is this liquid. ► We investigate properties of this convection. ► It leads to hydrothermal activity, that could be important for thermal state of Titan interior. Titan is the only body, beside the Earth, where liquid is present on the surface. This paper is aimed to show the properties of possible convection in a porous regolith on Titan. In our previous work (Czechowski, L., Kossacki, K.J. [2009]. Icarus 202, 599–607) we showed, that the Rayleigh number Ra can exceed its critical value Ra c. Hence, the convective motion of liquid filling pores in the regolith is likely for Titan relevant parameters. In the present work we investigate the properties of finite amplitude convection, i.e. for Ra > Ra cr. We study the basic properties of the steady state solution, the Nusselt number, the density of the heat flow and the average temperatures. Evolution of the convection is also considered. We conclude that any reasonable thermal model of Titan’s regolith should take into account the possibility of the considered convection. We discuss also possibility of identification of this convection (or its consequences in the form of evaporates) by the Cassini and possible future spacecrafts.