Sensitivity study of ozone retrieval from UV measurements on geostationary platforms

This paper addresses several aspects related to ultraviolet (UV) measurements from an upcoming geostationary orbit (GEO) satellite mission. First, using simulated cloud coverage based on the MTSAT (Multi-functional Transport Satellite 1R) 650 nm channel as a proxy, we find that GEO observations can increase clear-sky coverage by ~ 4 times. Secondly, we examine the feasibility of improved ozone detection with GEO observations, using synthetic GEMS spectra with GEO geometries along with the TOMS total ozone algorithm and an ozone profile algorithm based on the optimal estimation method. The sensitivity of ozone retrievals to the lower troposphere is limited at large solar and satellite zenith angles, especially above 70° under clear-sky conditions. Third, we evaluate two new ideas for improving ozone retrieval sensitivity in the troposphere at large angle geometries; (1) a geosynchronous orbit with an inclination-angle of 30°, with smaller values of viewing zenith angles than those from a geostationary orbit; (2) a combination of UV measurements at multiple solar zenith angles to improve the accuracy of ozone profile retrievals.

► We quantified the increase in clear-sky coverage as one benefit of Geostationary observation.
► We used synthetic ultraviolet measurements to examine ozone retrieval from Geostationary orbits.
► Use of an inclined geosynchronous orbit was considered to reduce the viewing zenith angle.
► Use of measurements at multiple solar zenith angles was investigated in order to improve ozone retrievals for both stratosphere and troposphere.