Ozone trends and exceptional events as seen by the IASI remote sensors
Résumé
The French IASI satellite mission has amassed a remarkable 17-year radiance dataset, from which temperature, ozone and nitric acid profiles are retrieved both day and night, from pole to pole. Near real time measurements are routinely distributed by Eumetsat, allowing the monitoring of the ozone hole, the analysis of exceptional events such as stratospheric intrusions and sudden stratospheric warmings, as well as the observation of tropospheric increases of ozone associated with fires or local pollution events.
Recently, the entire IASI ozone dataset underwent reprocessing with the aim of creating a thoroughly homogeneous observational record suitable for climate trend analysis. This involved implementing radiance corrections to the raw recorded spectra and ensuring the use of consistent cloud, water vapour and temperature products, which are the main auxiliary data used for the ozone retrievals.
In this presentation, we will illustrate the evolution of global distributions over time, providing an analysis of observed changes since 2007. Additionally, we will show the impact of sudden stratospheric warming events in both the Southern and Northern Hemispheres on total ozone distributions. Finally, we will demonstrate the influence of the January 2022 Hunga Tonga volcano eruption on the ozone vertical distribution in the Southern Hemisphere.