On the Extraction of Martian Atmospheric Temperatures From the O 2 Airglow Emission at 1.27 μm: Application to Limb Observations by SPICAM
Weiwei He, Xinyu Kang, Haiyan Luo, Chuanhang Wu, Zhongyi Fu, Zhihua Wang, Kuijun Wu, Houmao WangAbstract
The Martian atmospheric temperature profile is a core parameter for studying the Martian climate environment and atmospheric thermodynamics. However, its observational data remain severely limited. This study achieves temperature profile retrieval in the altitude range of 0–80 km by using the O 2 (a 1 Δ g ) airglow spectral data acquired by the infrared channel of the Spectroscopy Spectrograph for the Investigation of Characteristics of the Atmosphere of Mars (SPICAM) in limb observation mode and combining photochemical reaction mechanisms with a radiative transfer model. Comparisons are made with the simulation data from the Mars Climate Database (MCD) and the observation data from the Mars Climate Sounder (MCS) to validate the feasibility and accuracy of this study. Results indicate that within the altitude range of 20–60 km, the errors of the retrieved temperature profiles are controlled within ±20 K, exhibiting high precision. The collisional annihilation of O 2 (a 1 Δ g ) and reduction in atmospheric density diminish retrieval accuracies at altitudes below 20 km and above 60 km, respectively. This study realizes Martian atmospheric temperature profile retrieval on the basis of 1.27 μm O 2 (a 1 Δ g ) airglow obtained from SPICAM limb observations, providing technical approaches and data support for the in‐depth exploration of Martian atmospheric dynamics and climate characteristics.