Preprints
https://doi.org/10.5194/acp-2019-315
https://doi.org/10.5194/acp-2019-315
13 May 2019
 | 13 May 2019
Status: this preprint was under review for the journal ACP but the revision was not accepted.

Is the photochemistry activity weak during haze events? – A novel exploration on the photoinduced heterogeneous reaction of NO2 on mineral dust

Tao Wang, Yangyang Liu, Yue Deng, Hanyun Cheng, Yang Yang, Yiqing Feng, Muhammad Ali Tahir, Xiaozhong Fang, Xu Dong, Kejian Li, Saira Ajmal, Aziz-Ur-Rahim Bacha, Iqra Nabi, Hongbo Fu, Liwu Zhang, and Jianmin Chen

Abstract. Despite the increased awareness of heterogeneous reaction on mineral dust, the knowledge of how the intensity of solar irradiation influences the photochemistry activity remains a crucially important part in atmospheric research. Relevant studies have not seriously discussed the photochemistry under weak sunlight during haze, and thus ignored some underlying pollution and toxicity. Here, we investigated the heterogeneous formation of nitrate and nitrite under various illumination conditions by laboratory experiments and field observations. Observed by in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), water-solvated nitrate was the main surface product, followed by other species varying with illumination condition. The growth of nitrate formation rate tends to be slow after the initial fast with increasing light intensity. For example, the geometric uptake coefficient (γgeo) under 30.5 mW/cm2 (5.72 × 10−6) has exceeded the 50 % of that under 160 mW/cm2 (1.13 × 10−5). This case can be explained by the excess NO2 adsorption under weak illumination while the excess photoinduced active species under strong irradiation. Being negatively associated with nitrate (R2 = 0.748, P < 0.01), nitrite acts as the intermediate and decreases with increasing light intensity via oxidation pathways. Similar negative dependence appears in coarse particles collected during daytime (R2 = 0.834, P < 0.05), accompanied by the positive association during nighttime (R2 = 0.632, P < 0.05), suggesting illumination a substantial role in atmospheric nitrogen cycling. Overall, for the nitrate formation, the conspicuous response under slight illumination offers opportunities to explain the secondary aerosol burst during haze episodes with weak irradiation. Additionally, high nitrite levels accompanied by low nitrate concentrations may induce great health risk which was previously neglected. Further, Monte Carlo simulation coupled with sensitivity analysis may provide a new insight in the estimations of kinetics parameters for atmospheric modelling studies.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Tao Wang, Yangyang Liu, Yue Deng, Hanyun Cheng, Yang Yang, Yiqing Feng, Muhammad Ali Tahir, Xiaozhong Fang, Xu Dong, Kejian Li, Saira Ajmal, Aziz-Ur-Rahim Bacha, Iqra Nabi, Hongbo Fu, Liwu Zhang, and Jianmin Chen
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Tao Wang, Yangyang Liu, Yue Deng, Hanyun Cheng, Yang Yang, Yiqing Feng, Muhammad Ali Tahir, Xiaozhong Fang, Xu Dong, Kejian Li, Saira Ajmal, Aziz-Ur-Rahim Bacha, Iqra Nabi, Hongbo Fu, Liwu Zhang, and Jianmin Chen
Tao Wang, Yangyang Liu, Yue Deng, Hanyun Cheng, Yang Yang, Yiqing Feng, Muhammad Ali Tahir, Xiaozhong Fang, Xu Dong, Kejian Li, Saira Ajmal, Aziz-Ur-Rahim Bacha, Iqra Nabi, Hongbo Fu, Liwu Zhang, and Jianmin Chen

Viewed

Total article views: 2,185 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
1,622 502 61 2,185 149 59 59
  • HTML: 1,622
  • PDF: 502
  • XML: 61
  • Total: 2,185
  • Supplement: 149
  • BibTeX: 59
  • EndNote: 59
Views and downloads (calculated since 13 May 2019)
Cumulative views and downloads (calculated since 13 May 2019)

Viewed (geographical distribution)

Total article views: 2,086 (including HTML, PDF, and XML) Thereof 2,076 with geography defined and 10 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 13 Jun 2024
Download
Short summary
We studied the heterogeneous formation of nitrate and nitrite aerosols by in-situ laboratory tests and field observations. Sunlight becomes the protagonist under weak illumination, while a costar under strong irradiation, attributing to the balance between NO2 adsorption and the formation of photoinduced active species. Meanwhile, sunlight determines the association between atmospheric nitrate and nitrite. We hope this work offer more suggestions for modelling studies.
Altmetrics