Articles | Volume 19, issue 6
https://doi.org/10.5194/amt-19-2009-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-19-2009-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
19 Mar 2026
Research article |
| 19 Mar 2026
| 19 Mar 2026
A novel short-pathlength photoreactor to study aqueous-phase photochemistry: application to biomass-burning phenols
Christopher Niedek
Department of Environmental Toxicology, University of California, 1 Shields Ave., Davis, California 95616, United States
Wenqing Jiang
Department of Environmental Toxicology, University of California, 1 Shields Ave., Davis, California 95616, United States
Antai Zhang
Department of Environmental Toxicology, University of California, 1 Shields Ave., Davis, California 95616, United States
Cort Anastasio
Department of Land, Air, and Water Resources, University of California, 1 Shields Avenue, Davis, California 95616, United States
Department of Environmental Toxicology, University of California, 1 Shields Ave., Davis, California 95616, United States
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Wenqing Jiang, Christopher Niedek, Cort Anastasio, and Qi Zhang
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We studied how aqueous-phase secondary organic aerosol (aqSOA) form and evolve from a phenolic carbonyl commonly present in biomass burning smoke. The composition and optical properties of the aqSOA are significantly affected by photochemical reactions and are dependent on the oxidants' concentration and identity in water. During photoaging, the aqSOA initially becomes darker, but prolonged aging leads to the formation of volatile products, resulting in significant mass loss and photobleaching.
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In summer 2019 at Mt. Bachelor Observatory, we observed smoke from wildfires with transport times ranging from less than a day up to 2 weeks. Aerosol absorption of multi-day transported smoke was dominated by black carbon, while smoke with shorter transport times had greater brown carbon absorption. Notably, Siberian smoke exhibited aerosol scattering and physical properties indicative of contributions from larger particles than typically observed in smoke.
Christopher R. Niedek, Fan Mei, Maria A. Zawadowicz, Zihua Zhu, Beat Schmid, and Qi Zhang
Atmos. Meas. Tech., 16, 955–968, https://doi.org/10.5194/amt-16-955-2023, https://doi.org/10.5194/amt-16-955-2023, 2023
Short summary
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This novel micronebulization aerosol mass spectrometry (MS) technique requires a low sample volume (10 μL) and can quantify nanogram levels of organic and inorganic particulate matter (PM) components when used with 34SO4. This technique was successfully applied to PM samples collected from uncrewed atmospheric measurement platforms and provided chemical information that agrees well with real-time data from a co-located aerosol chemical speciation monitor and offline data from secondary ion MS.
Xinghua Zhang, Wenhui Zhao, Lixiang Zhai, Miao Zhong, Jinsen Shi, Junying Sun, Yanmei Liu, Conghui Xie, Yulong Tan, Kemei Li, Xinlei Ge, Qi Zhang, Shichang Kang, and Jianzhong Xu
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2022-211, https://doi.org/10.5194/essd-2022-211, 2022
Manuscript not accepted for further review
Short summary
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A comprehensive aerosol observation project was carried out in the Tibetan Plateau (TP) in recent years to investigate the properties and sources of atmospheric aerosols as well as their regional differences by performing multiple short-term intensive field observations. The real-time online high-time-resolution (hourly) data of aerosol properties in the different TP region are integrated in a new dataset and can provide supporting for related studies in in the TP.
Ted Hullar, Theo Tran, Zekun Chen, Fernanda Bononi, Oliver Palmer, Davide Donadio, and Cort Anastasio
Atmos. Chem. Phys., 22, 5943–5959, https://doi.org/10.5194/acp-22-5943-2022, https://doi.org/10.5194/acp-22-5943-2022, 2022
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Chemicals are commonly found in snowpacks throughout the world and may be degraded by sunlight; some previous research has reported faster decay rates for chemicals on the surface of snow and ice compared to in water. We found photodegradation on snow can be as much as 30 times faster than in solution for the three dimethoxybenzene isomers. Our computational modeling found light absorbance by dimethoxybenzenes increases on the snow surface, but this only partially explains the decay rate.
Fan Mei, Jian Wang, Shan Zhou, Qi Zhang, Sonya Collier, and Jianzhong Xu
Atmos. Chem. Phys., 21, 13019–13029, https://doi.org/10.5194/acp-21-13019-2021, https://doi.org/10.5194/acp-21-13019-2021, 2021
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This work focuses on understanding aerosol's ability to act as cloud condensation nuclei (CCN) and its variations with organic oxidation level and volatility using measurements at a rural site. Aerosol properties were examined from four air mass sources. The results help improve the accurate representation of aerosol from different ambient aerosol emissions, transformation pathways, and atmospheric processes in a climate model.
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Short summary
We developed a new photoreactor to study how organic compounds react in water under atmospheric-relevant conditions. Experiments were performed on smoke-related chemicals under controlled light, temperature, and humidity mimicking cloud and haze environments. Our results showed that saltier water speeds particle formation and changes their composition, providing new insights into atmospheric aerosol chemistry.
We developed a new photoreactor to study how organic compounds react in water under...
