Upper limits of CH4 and OCS in the Martian atmosphere from NOMAD/TGO solar occultation: A study of vertical averaging and systematic uncertainties - M. Escudero-Jiménez; M.A. López-Valverde; J. Peralta; T. Moya; A. Belmonte; A. Brines; I. Thomas; G. Villanueva; G. Liuzzi; E. Knutsen; S. Viscardy; F. González-Galindo; et al. (Icarus, 2026)