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SUMMARY:An alkaline world: a new assessment of the global chemical climate
  for PM2.5 formation and nitrogen and sulphur deposition - Dr Yao Ge\, Uni
 versity of Cambridge
DTSTART:20251118T110000Z
DTEND:20251118T120000Z
UID:TALK239926@talks.cam.ac.uk
CONTACT:Yao Ge
DESCRIPTION:Abstract :\nThe  reduction of atmospheric reactive nitrogen (N
 r) and sulfur (Sr) species  is a key objective for air quality control pol
 icies as they contribute to the formation of PM2.5\, which has significant
  effects on human health  and climate\, and their deposition affects ecosy
 stem productivity. The  chemical climate for Nr and Sr pollution has under
 gone dramatic changes in the past two decades. Therefore\, it is necessary
  to update our understanding of global Nr and Sr chemistry and investigate
  their mitigation under current atmospheric conditions. Since a range of e
 mission sources and atmospheric chemical and physical processes contribute
  to Nr and Sr concentrations\, atmospheric chemistry transport models (ACT
 Ms) are essential tools to identify the key processes controlling their im
 pacts and effective mitigation. In this talk\, I will present my research 
 on global modelling of Nr and Sr species using the EMEP MSC-W CTM coupled 
 with WRF meteorology. Firstly\, I will introduce the model-measurement com
 parisons of reduced nitrogen (RDN)\, oxidized nitrogen (OXN)\, and oxidize
 d sulfur (OXS) species covering 10 monitoring networks worldwide that meas
 ure surface concentrations and wet deposition. Secondly\, I will summarize
  our global analysis of current Nr and Sr gas-aerosol partitioning and reg
 ional budgets. This analysis quantitatively demonstrates that successful c
 ontrol of SO2 and NOx emissions has resulted in atmospheric NH3 excess in 
 many areas\, leading to a new significance of alkaline air\, with adverse 
 impacts on ecosystems. Finally\, I will present our work that quantifies t
 he sensitivities of emissions reductions for mitigating PM2.5 and N and S 
 deposition. This work highlights a global picture of the effectiveness of 
 NH3\, NOx\, and SOx emissions reductions for mitigating both concentration
 s and deposition of Nr and Sr pollutants.\n\nBiography :\nDr Yao Ge is a p
 ostdoctoral researcher in the Yusuf Hamied Department of Chemistry at the 
 University of Cambridge\, where she focuses on improving the representatio
 n of the global marine sulfur cycle in climate models. Previously\, she wa
 s a Research Scientist at the Norwegian Meteorological Institute (MET Norw
 ay)\, investigating how anthropogenic \nvolatile organic compounds contrib
 ute to the formation of atmospheric surface ozone and secondary organic ae
 rosols. Dr Yao Ge holds a PhD in Chemistry from the University of Edinburg
 h\, where her research involved the global atmospheric modelling of inorga
 nic reactive nitrogen and sulfur species using the EMEP model.
LOCATION:Chemistry Dept\, Unilever Lecture Theatre and Teams
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