Investigating the ability of satellite occultation instruments to monitor possible geoengineering experiments

Abstract

Solar radiation management is a method in the field of geoengineering that aims to modify the Earth’s shortwave radiation budget. One idea is to inject sulfur dioxide or sulfuric acid into the stratosphere, where sulfate aerosols are then formed. Such experiments can probably be observed, for example, with satellite occultation instruments like SAGE III/ISS. The aim of the current study is to analyse, using MAECHAM-HAM simulations and retrievals with the radiative transfer program SCIATRAN, whether it is possible to detect the formed stratospheric aerosols from emissions of 1 and 2 Tg S yr−1 (sulfur per year) with the currently active satellite occultation instruments, taking into account an error estimate that is as realistic as possible. If these smaller amounts of sulfur are detectable, larger amounts will also be detectable. The calculations show that, considering the natural variability and the assumptions made here, the stratospheric aerosols formed from emissions of 1 and 2 Tg S yr−1 in the quasi-steady-state phase can be detected, which is not the case in the first month of the 2-year initial phase.