Ozone Impacts of Gas-Aerosol Uptake in Global Chemistry Transport Models

Stadtler, Scarlet; Schultz, Martin; Schröder, Sabine; Simpson, David; Bott, Andreas; Taraborrelli, Domenico

doi:10.5194/acp-2017-566

Journal Article

FZJ-2017-05091

Ozone Impacts of Gas-Aerosol Uptake in Global Chemistry Transport Models

Stadtler, S.FZJ* ; Simpson, D. (Corresponding author) ; Schröder, S.FZJ* ; Taraborrelli, D.FZJ* ; Bott, A. ; Schultz, M.FZJ*

2017
EGU Katlenburg-Lindau

Atmospheric chemistry and physics / Discussions 566, 1 - 35 (2017) [10.5194/acp-2017-566]

This record in other databases:

Please use a persistent id in citations: http://hdl.handle.net/2128/15105 doi:10.5194/acp-2017-566

Abstract: The impact of six heterogeneous gas-aerosol uptake reactions on tropospheric ozone and nitrogen species was studied using two chemical transport models, EMEP MSC-W and ECHAM-HAMMOZ. Species undergoing heterogeneous reactions in both models include N2O5, NO3, NO2, O3, HNO3 and HO2. Since heterogeneous reactions take place at the aerosol surface area, the modeled surface area density Sa of both models was compared to a satellite product retrieving the surface area. This comparison shows a good agreement in global pattern and especially the capability of both models to capture the extreme aerosol loadings in East Asia.The impact of the heterogeneous reactions was evaluated by the simulation of a reference run containing all heterogeneous reactions and several sensitivity runs. One reaction was turned off in each sensitivity run to compare it with the reference run. The analysis of the sensitivity runs confirms that the globally most important heterogeneous reaction is the one of N2O5. Nevertheless, NO2, HNO3 and HO2 heterogeneous reaction gain relevance particularly in East Asia due to the presence of high NOx concentrations and high Sa in the same region, although ECHAM-HAMMOZ showed much stronger responses than EMEP in this respect. The heterogeneous reaction of O3 itself on dust is of minor relevance compared to the other heterogeneous reactions. The impacts of the N2O5 reactions show strong seasonal variations, with biggest impacts on O3 in spring time when photochemical reactions are active and N2O5 levels still high. Evaluation of the models with northern hemispheric ozone surface observations yields a better agreement of the models with observations in terms of concentration levels, variability, and temporal correlations at most sites when the heterogeneous reactions are incorporated.

Classification: