Speaker
Description
The Changing-Atmosphere Infra-Red Tomography Explorer (CAIRT) is one of the four candidates for ESA’s Earth Explorer 11. This mission has been proposed in order to achieve a step change in our understanding of the coupling of atmospheric circulation, composition and regional climate. The CAIRT concept proposes to perform limb tomography of the atmosphere from the troposphere to the lower thermosphere (about 5 to 115 km altitude) with a swath between 300 and 500 km and having high spatial and spectral resolution to provide a three-dimensional picture of atmospheric structure at unprecedented scales.
This contribution will investigate the capability of CAIRT to analyse stratosphere to troposphere exchange using an Observing System Simulation Experiment (OSSE). In this effort, a reference atmosphere – the nature run in the OSSE terminology – is built based on the Copernicus Atmosphere Monitoring Services (CAMS) control run in 2021 (i.e. with a horizontal resolution ~40 km and a vertical resolution ~500 m in the tropopause region). The nature run is used to generate CAIRT ozone profiles, along with a CAIRT orbit simulator and a simulator to generate CAIRT ozone retrieval responses and error covariance matrix. Simulated CAIRT ozone profiles are then assimilated by the Belgian Assimilation System for Chemical ObsErvations (BASCOE) to provide ozone analyses – the assimilation run. In order to measure the added value of CAIRT data in the assimilation run, a BASCOE control run without CAIRT assimilation, is also done. Ozone fluxes across the tropopause are calculated from these three numerical experiments which will be discussed in this presentation.
