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Model development

Duseong Jo

Seconday organic aerosol (SOA) simulation

  •   Organic aerosol (OA) constitutes significant mass fractions (20% to 90%) of total dry fine aerosols in the atmosphere. However, the effect of OA on climate is unclear because of an incomplete understanding of its sources, chemical formation, and physical and chemical characteristics. In particular, secondary organic aerosols (SOAs), which are produced in the atmosphere from gas-phase precursors, are poorly understood relative to primary organic aerosols (POAs), which are directly emitted from sources. 
  •   Global models of OA have shown large discrepancies when compared to the observed values because of the limited capability to simulate SOA. Such simulations poorly represent complex SOA formation in the atmosphere and have been primarily based on the gas-particle partitioning of semi-volatile organics.
  •   Many studies have recently shown that chemical aging reactions in the atmosphere are important because they can lead to decreases in organic volatility, resulting in increases of SOA mass yields. This photochemical aging, which cannot be properly measured in chemical chambers, may contribute to the very low bias in models that do not simulate chemical aging processes in the atmosphere, especially photochemical aging progresses.  
Yujin Ok

Simulation of Volatile Organic Compounds (VOCs)

Volatile Organic Compounds (VOCs) play an important role in the atmosphere as a precursor of aerosols and ozone, which are key air pollutants. While their atmospheric role as parent species of aerosols and ozone is highly emphasized in many studies, it is difficult to quantify their atmospheric impacts due to the complexity of chemical reactions and relatively short lifetimes, as well as the uncertainty of their emission sources.

We aim to gain a better understanding of the photochemistry and regional impacts of VOCs using Chemical Transport Models (CTMs). Among the various VOC species, aromatic compounds (benzene, toluene, xylenes) are in particular interest because of their abundance, high reactivity and contribution in total VOC emissions. Therefore, we examine the sensitivity of simulated trace gases such as ozone, nitrogen oxide to the inclusion of aromatic chemistry in the model. Model simulations can also be used for evaluation of emission inventories and understanding the emission characteristics of VOCs.