CO2 retrievals in the Mars daylight thermosphere from its 4.3 μm limb emission measured by OMEGA/MEx

Density and Temperature of the Upper Mesosphere and Lower Thermosphere of Mars Retrieved From the OI 557.7 nm Dayglow Measured by TGO/NOMAD

“…Figure 4 shows the scheme of the retrieval process developed in this study. The core of the inversion scheme is based on the Bayesian algorithm (Rodgers, 2000), which is widely used in non-linear inversion problems in remote-sensing observations of atmosphere (e.g., Grassi et al, 2005;Jiménez-Monferrer et al, 2021). This method iteratively calculates new solutions based on the measurements and a priori information:…”

“…Figure 4 shows the scheme of the retrieval process developed in this study. The core of the inversion scheme is based on the Bayesian algorithm (Rodgers, 2000), which is widely used in non‐linear inversion problems in remote‐sensing observations of atmosphere (e.g., Grassi et al., 2005; Jiménez‐Monferrer et al., 2021). This method iteratively calculates new solutions based on the measurements and a priori information: $$${{x}_{i}}_{+1}={x}_{i}+{\left({S}_{a}^{-1}+{K}_{i}^{T}{S}_{e}^{-1}{K}_{i}\right)}^{-1}\left[{K}_{i}^{T}{S}_{e}^{-1}\left(y-F\left({x}_{i}\right)\right)-{S}_{a}^{-1}\left({x}_{i}-{x}_{a}\right)\right]$$$ where x is a vector of retrieved parameters (CO 2 density profile, temperature profile, and a factor for flux correction, in this study), x i is the solution in the previous iteration , x i+1 is the new solution), y is a vector of measured limb profile of oxygen dayglow brightness, S e is a covariance matrix of measurement errors, x a is an a priori vector, S a is a covariance matrix of a priori information, F ( x i ) is a vector calculated by the forward model with x i (calculated vertical profile of oxygen dayglow brightness), and K i is a Jacobian matrix, that is, the partial derivative of the forward model with respect to x i , K i = ∂F/∂x i .…”

Martian Atmospheric Temperature and Density Profiles During the First Year of NOMAD/TGO Solar Occultation Measurements

“…Very well tested on Earth atmosphere remote sounding projects, Kopra integrates the RT equation along the observed LOS which is computed for an ellipsoidal planetary surface including consideration of refraction. KOPRA was recently adapted to limb emissions on Mars (Jiménez-Monferrer et al, 2021), and now it has been adapted to solar occultation data on Mars for the first time, and in particular to the NOMAD/SO channel with implementation of the asymmetric AOTF transfer function and the double Gaussian ILS.…”

Water Vapor Vertical Distribution on Mars During Perihelion Season of MY 34 and MY 35 With ExoMars‐TGO/NOMAD Observations

“…As a line-by-line and layer-by-layer code, KOPRA was designed to calculate the infrared radiative transfer through the atmosphere. An extensive description of this line-by-line radiative transfer algorithm can be found in Stiller (2000. Originally developed for the Earth, KOPRA was recently adapted to limb emissions on Mars (Jiménez-Monferrer et al, 2021) and for this work it has been adapted to SO data on Mars for the first time. Some modifications have been made in order to make the code suitable for the analysis of the NOMAD data.…”