Synergetic Effects of Isoprene and HO<sub><i>x</i></sub> on Biogenic New Particle Formation

Tiszenkel, Lee; Lee, Shan‐Hu

doi:10.1029/2023gl103545

Cited by 2 publications

(1 citation statement)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ethanol CIMS instrument used has been described in detail previously [Benson et al, 2010;Mark E. Erupe et al, 2010;M. E. Erupe et al, 2011;Lee Tiszenkel and Lee, 2023;L. Tiszenkel et al, 2019;You et al, 2014;.…”

Section: Methodsmentioning

confidence: 99%

Measurement Report: Urban Ammonia and Amines in Houston, Texas

Tiszenkel,

Flynn,

Lee

2024

Preprint

View full text Add to dashboard Cite

Abstract. Ammonia and amines play critical roles in secondary aerosol formation, especially in urban environments. However, fast measurements of ammonia and amines in the atmosphere are very scarce. We measured ammonia and amines with a chemical ionization mass spectrometer (CIMS) at the urban center in Houston, Texas, the fourth most populated urban site in the United States, during October 2022. Ammonia concentrations were on average 4 parts per billion in volume (ppbv), while the concentration of an individual amine ranged from several parts per trillion in volume (pptv) to hundreds of pptv. These reduced nitrogen compounds were more abundant during the weekdays than on weekends and correlated with measured CO concentrations, implying they were mostly emitted from pollutant sources. Both ammonia and amines showed a distinct diurnal cycle, with higher concentrations in the warmer afternoon, indicating dominant gas-to-particle conversion processes taking place with the changing ambient temperatures. Studies have shown that dimethylamine is critical for urban new particle formation (NPF), but currently, there are no amine emission inventories in global climate models (as opposed to ammonia). Our observations show that amines in general positively correlated with ammonia, indicating that it is reasonable for global models to use scaled-down ammonia concentrations (e.g., 0.1 %) as a proxy of urban dimethylamine concentrations to simulate urban NPF processes.

show abstract

Section: Methodsmentioning

confidence: 99%

Measurement Report: Urban Ammonia and Amines in Houston, Texas

Tiszenkel,

Flynn,

Lee

2024

Preprint

View full text Add to dashboard Cite

show abstract

Observation-constrained kinetic modeling of isoprene SOA formation in the atmosphere

Shen,

Yang,

Thornton

et al. 2024

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Isoprene has the largest global non-methane hydrocarbon emission, and the oxidation of isoprene plays a crucial role in the formation of secondary organic aerosol (SOA). Two primary processes are known to contribute to SOA formation from isoprene oxidation: (1) the reactive uptake of isoprene-derived epoxides on acidic or aqueous particle surfaces and (2) the absorptive gas–particle partitioning of low-volatility oxidation products. In this study, we developed a new multiphase condensed isoprene oxidation mechanism that includes these processes with key molecular intermediates and products. The new mechanism was applied to simulate isoprene gas-phase oxidation products and SOA formation from previously published chamber experiments under a variety of conditions and atmospheric observations during the Southern Oxidant and Aerosol Studies (SOAS) field campaign. Our results show that SOA formation from most of the chamber experiments is reasonably reproduced using our mechanism, except when the concentration ratios of initial nitric oxide to isoprene exceed ∼ 2, the formed SOA is significantly underpredicted. The SOAS simulations also reasonably agree with the measurements regarding the diurnal pattern and concentrations of different product categories, while the total isoprene SOA remains underestimated. The molecular compositions of the modeled SOA indicate that multifunctional low-volatility products contribute to isoprene SOA more significantly than previously thought, with a median mass contribution of ∼ 57 % to the total modeled isoprene SOA. However, this contribution is intricately intertwined with IEPOX-derived SOA (IEPOX: isoprene-derived epoxydiols), posing challenges for their differentiation using bulk aerosol composition analysis (e.g., the aerosol mass spectrometer with positive matrix factorization). Furthermore, the SOA from these pathways may vary greatly, mainly dependent on the volatility estimation and treatment of particle-phase processes (i.e., photolysis and hydrolysis). Our findings emphasize that the various pathways to produce these low-volatility species should be considered in models to more accurately predict isoprene SOA formation. The new condensed isoprene chemical mechanism can be further incorporated into regional-scale air quality models, such as the Community Multiscale Air Quality Modelling System (CMAQ), to assess isoprene SOA formation on a larger scale.

show abstract

Synergetic Effects of Isoprene and HO_x on Biogenic New Particle Formation

Cited by 2 publications

References 64 publications

Measurement Report: Urban Ammonia and Amines in Houston, Texas

Measurement Report: Urban Ammonia and Amines in Houston, Texas

Observation-constrained kinetic modeling of isoprene SOA formation in the atmosphere

Contact Info

Product

Resources

About

Synergetic Effects of Isoprene and HOx on Biogenic New Particle Formation

Cited by 2 publications

References 64 publications

Measurement Report: Urban Ammonia and Amines in Houston, Texas

Measurement Report: Urban Ammonia and Amines in Houston, Texas

Observation-constrained kinetic modeling of isoprene SOA formation in the atmosphere

Contact Info

Product

Resources

About

Synergetic Effects of Isoprene and HO_x on Biogenic New Particle Formation