Stratospheric modelling at BIRA-IASB focus on the study of the ozone layer and its interaction with climate change. This is done with the Belgian Assimilation System for Chemical ObErvations (BASCOE) which has been developed for almost 20 years. With this system, analyses of ozone and related chemical species are delivered daily which contributes to the monitoring of the ozone layer. BASCOE is also used to provide a reanalysis dataset of the stratospheric chemical composition for the period 2004-2016. Our datasets can be downloaded here. The system is also used to study the impact of climate change on the ozone layer. More information on our projects can be found here.