Variations in Vertical CO/CO2 Profiles in the Martian Mesosphere and Lower Thermosphere Measured by the ExoMars TGO/NOMAD: Implications of Variations in Eddy Diffusion Coefficient

Yoshida, Nao; Nakagawa, Hiromu; Aoki, Shohei; Erwin, Justin; Vandaele, Ann Carine; Daerden, Frank; Thomas, Ian; Trompet, Loïc; Koyama, Shungo; Terada, Naoki; Neary, Lori; Murata, Isao; Villanueva, Geronimo; Liuzzi, Giuliano; Lopez‐Valverde, Miguel Angel; Brines, Adrian; Modak, Ashimananda; Kasaba, Yasumasa; Ristic, Bojan; Bellucci, Giancarlo; López‐Moreno, José Juan and Patel, Manish (2022). Variations in Vertical CO/CO2 Profiles in the Martian Mesosphere and Lower Thermosphere Measured by the ExoMars TGO/NOMAD: Implications of Variations in Eddy Diffusion Coefficient. Geophysical Research Letters, 49(10), article no. e2022GL098485.

DOI: https://doi.org/10.1029/2022gl09848

Abstract

Using the Nadir and Occultation for MArs Discovery instrument aboard Trace Gas Orbiter, we derived the CO/CO2 profiles between 75 and 105 km altitude with the equivalent width technique. The derived CO/CO2 profiles showed significant seasonal variations in the southern hemisphere with decreases near perihelion and increases near aphelion. The estimation of the CO/CO2 profiles with a one‐dimensional photochemical model shows that an altitude‐dependent eddy diffusion coefficient better reproduces the observed profiles than a vertically uniform one. Our estimation suggests that the eddy diffusion coefficient in Ls = 240–270 is uniformly larger by a factor of ∼2 than that in Ls = 90–120 in the southern hemisphere, while they are comparable in the northern hemisphere. This fact demonstrates that the eddy diffusion coefficient is variable with season and latitude.

Viewing alternatives

Look up in Google Scholar

Download history

Metrics

Public Attention

Altmetrics from Altmetric

Number of Citations

Citations from Dimensions

Item Actions

Export

About

CORE (COnnecting REpositories)

Recommendations