Disequilibrium chemistry in brown dwarfs

Planetary atmospheres are enriched with disequilibrium species by various dynamical, chemical and physical processes, whose characters they therefore divulge. This paper compares processes in Jupiter's atmosphere to those indicated in its more massive extrasolar cousin, the brown dwarf Gliese 229B. Disequilibrium mechanisms in G1229B are revealed by CO and Cs spectral features and point to fundamental similarities and differences between the atmospheric structure of a jovian planet and one more massive.