Motivated by the selection of the MATMOS instrument for the ExoMars Trace Gas Orbiter, we present a new method to retrieve temperature and pressure from spectra recorded by ACE. The Mars Atmospheric Trace Molecule Occultation Spectrometer (MATMOS) was a joint Canadian Space Agency (CSA) and Jet Propulsion Laboratory (JPL) mission to send a high-resolution Fourier transform spectrometer to Mars to operate in solar occultation mode. It would be very similar to the CSA's Atmospheric Chemistry Experiment (ACE), in Earth orbit since 2003. By exploiting the temperature dependence of absorption line depth in spectra of CO2, we can estimate the physical parameters of the atmosphere by analyzing fits of individual lines in vibration-rotation bands. We present preliminary results of this technique's application to spectra recorded over the Arctic and tropics by ACE-FTS and compare them to retrievals made by the ACE team and the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC).