Effects of the second virial coefficient on the adiabatic lapse rate of dry atmospheres

TL;DR

This paper investigates how the second virial coefficient influences the adiabatic lapse rate in dry atmospheres, providing thermodynamic calculations for various planets and exoplanets, and showing its significance in certain conditions.

Contribution

It introduces a detailed analysis of the second virial coefficient's impact on atmospheric lapse rates across different planetary environments, including corrections to experimental data.

Findings

The second virial coefficient significantly affects lapse rates in specific planetary atmospheres.

Inclusion of the second virial coefficient improves agreement with observed lapse rates for Venus and Titan.

The study compares effects of hard-sphere, van der Waals, and square-well potentials on thermodynamic parameters.

Abstract

We study the effect of the second virial coefficient on the adiabatic lapse rate of a dry atmosphere. To this end, we compute the corresponding adiabatic curves, the internal energy, and the heat capacity, among other thermodynamic parameters. We apply these results to Earth, Mars, Venus, Titan, and the exoplanet G1 851d, considering three physically relevant virial coefficients in each case: the hard-sphere, van der Waals, and the square-well potential. These examples illustrate under which atmospheric conditions the effect of the second virial coefficient is relevant. Taking the latter into account yields corrections towards the experimental values of the lapse rates of Venus and Titan in some instances.