The Geostationary Earth Orbit (GEO) provides a unique opportunity of monitoring tropospheric pollutants on the
regional scale. Thermal InfraRed (TIR) observations (from about 620-2300 cm<sup>-1</sup>) have two advantages over other
spectral domains: firstly, day/night observations are possible; secondly, numerous molecular species can be observed
simultaneously. However, the sensitivity of TIR observations may be a critical point for the geostationary orbit geometry.
In this study, we present a feasibility study for TIR pollution observations in GEO conditions. The capabilities of
measuring the tropospheric abundance of ozone (O<sub>3</sub>) and carbon monoxide (CO) are investigated. Limitations of the
sensor sensitivity are also discussed.