2024/04/15 by M. Grimsditch, Grimsditch, Marcos, В. Г. Карпов +1
Earth and Planetary Sciences · #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Geophysics and Gravity Measurements #Solar and Stellar Astrophysics (astro-ph.SR) #Statistical Mechanics (cond-mat.stat-mech)
paper · pdf · doi:10.48550/arxiv.2404.09700
openalex publication_date 2024/04/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The barometric equation predicts the molecular concentration n(z) exponentially decaying with altitude z. Because the mean free path l=1/nσ increases exponentially, at high altitudes z, the equation is no longer within the domain of applicability of the standard kinetic theory. \citegrimsditch Here, we predict the dependence n(z)∝ z-2 for the case l≫ L in uniform gravity and n(z)∝ [ln(1+z/R0)]-2 when z≫ R0 for a planet of radius R0. It corresponds to a non-stationary planetary atmosphere with hydrogen accretion. The accretion is accompanied by a release of gravitational potential energy that could be the elusive source driving the formation of stellar coronas. Other consequences include slowly decaying tails of planetary atmospheres and periodical hydrogen explosions of white dwarfs.