TY  - THES
AB  - Photochemical reactions with the reactive halogen atoms Cl and Br mostly cause stratospheric ozone depletion. The chlorine- and bromine-containing very short-lived species (VSLS), which have an atmospheric lifetime of less than six months, play an essential role in stratospheric total bromine loading. However, there is considerable uncertainty about the geographical distribution of their sources, and therefore, it is challenging to reproduce the observations. In order to describe the stratospheric or regional abundance of bromine from VSLS, it is of great importance to quantify the lower boundary conditions of these species. In order to increase our understanding of the role of brominated species in the stratosphere, the Chemical Lagrangian Model of the Stratosphere (CLaMS) has been used to investigate the global surface mixing ratio and lower boundary conditions for the simulation in this thesis. The simulation uses a ‘top-down approach, where atmospheric measurements from aircraft are used in combination with models to quantify and refine the lower boundary emissions. The findings of this thesis reveal that the simulation incorporating a monthly global lower boundary, featuring notable seasonal and zonal variations, exhibits enhanced concordance with observations obtained during the SouthTRAC campaign. However, the elevated mixing ratio of CHBr3 and CH2Br2 in the upper atmosphere was not confirmed by climatological upper tropospheric and stratospheric data, presumably due to slow up- ward transport. Moreover, the exceedingly high values detected in specific regions at the estimated lower boundary are likely attributed to the limited available observations from the SouthTRAC campaign. This underscores the necessity for additional observations during spring and summer, as well as observation data from higher latitudes in the Northern Hemisphere, to comprehensively construct the lower boundary distribution of CHBr3 and CH2Br2.
AU  - Zheng, Siyuan
CY  - Wuppertal
DA  - 2024
DO  - 10.25926/BUW/0-524
DP  - Bergische Universität Wuppertal
LA  - eng
N1  - Tag der Verteidigung: 17.06.2024
N1  - Gesehen am 24.10.2024
N1  - Bergische Universität Wuppertal, Dissertation, 2024
PB  - Veröffentlichungen der Universität
PY  - 03.04.2024
SP  - 1 Online-Ressource (2, ii, 160 Seiten)
T2  - Physik
TI  - Investigation of lower boundary conditions of brominated very short-lived species (VSLS)
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:468-2-2884
Y2  - 2024-11-20T18:35:13
ER  -