Speaker
Description
We present trace gas and aerosol measurements obtained by the airborne infrared imaging limb sounder GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) that has been operated onboard the research aircraft Geophysica within the Asian Monsoon during the StratoClim campaign (July 2017) and onboard HALO (High Altitude and Long Range Research Aircraft) above the South Atlantic during the SouthTRAC campaign (September-November 2019). We show retrieval results of ammonia (NH$_3$) and solid ammonium nitrate (AN) as two-dimensional trace-gas distributions derived from GLORIA observations in the UT (Upper Troposphere). Retrieval performance and characteristics are discussed in detail. In this contribution, we further compare GLORIA measurements with results of the CAMS (Copernicus Atmosphere Monitoring Service) reanalysis and forecast model. The GLORIA observations reveal large enhancements of NH$_3$ of around 1 ppbv in the Asian Monsoon upper troposphere, but no clear indication of NH$_3$ in biomass burning plumes in the upper troposphere above the South Atlantic (instrument detection limit around 10 pptv). In contrast, CAMS reanalysis and forecast simulation results indicate strong enhancements of NH$_3$ in both measured scenarios. Comparisons of other retrieved pollution gases, such as peroxyacetyl nitrate (PAN) show the ability of CAMS models to reproduce the biomass burning plumes above the South Atlantic in general. However, NH$_3$ concentrations seem to be largely overestimated by the models within these plumes.
