Implementation of sulfur hexafluoride (SF6) in the Belgian Assimilation System for Chemical ObsErvations (BASCOE)

Sulfur hexafluoride (SF₆) is a greenhouse gas that is emitted at the surface because of its use as an insulator in electrical transmission equipment and electronic devices. Since its quasi-linear emission growth and its very long lifetime, SF₆ can be used as a tracer for the Age of Air (AoA) to diagnose changes in the Brewer Dobson Circulation (BDC). The chemistry of SF₆ has been implemented in the Chemistry Transport Model (CTM) of the Belgian Assimilation System for Chemical ObsErvations (BASCOE). Reaction rates were taken from previous studies while an electron density has been taken from WACCM-X-SD simulations.
In this contribution, BASCOE-CTM simulations driven by ERA5 and MERRA2 will be discussed considering SF₆ with and without mesospheric sinks (i.e. passive SF₆ in the latter case). During the course of the simulations, the computed mixing ratios have also been saved in the space of MIPAS observations to analyse the impact of the MIPAS sampling in its AoA derivation.