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| DOI | 10.1016/j.atmosres.2020.105390 |
| Effectiveness of airborne radon progeny assessment for atmospheric studies | |
| Crova F.; Valli G.; Bernardoni V.; Forello A.C.; Valentini S.; Vecchi R. | |
| 发表日期 | 2021 |
| ISSN | 0169-8095 |
| 卷号 | 250 |
| 英文摘要 | In this paper, measurements of short- and long-lived Radon progeny attached to atmospheric fine aerosols are reported. Hourly measurements of 222Rn short-lived decay products (i.e. 214Bi via on-line alpha spectrometry on 214Po) in the atmosphere were carried out in Milan (Italy) from 1999 to 2016; 214Bi mean concentrations ranged from 0.2 to 38.1 Bq m−3. It is noteworthy that minima occurred in springtime although the strongest convective turbulence can be expected in summer, when the highest solar radiation is available; one order of magnitude higher values were observed in winter when the Po valley experienced poor atmospheric dilution. The Theil-Sen method was applied to investigate the long-time trend in de-seasonalised data series. Results showed that - although inter/intra-annual variations in 214Bi concentrations were observed in connection with differences in atmospheric dispersion conditions – no statistically significant trend over the investigated period was detected. On a sub-set of these samples, also weekly 210Pb concentrations were determined via off-line alpha spectrometry on 210Po; atmospheric activity concentration values ranged between 0.13 and 3.05 mBq m−3. The seasonal behaviour of 210Pb concentrations followed fairly well the 214Bi temporal pattern, showing that mixing layer dynamics is paramount in determining short- and long-lived Radon progeny levels in the atmosphere. From 210Pb/214Bi activity ratio, the residence time τres of fine aerosols in the atmosphere was estimated to be on average 1 day, ranging from 11.0 to 55.3 h without any evident temporal trend. By exploiting the availability of mixing layer height data at our site, an alternative approach to estimate aerosol residence time was tested; this was based on a simple relationship relying on deposition velocity (from literature data) and mixing layer height (available at our monitoring station). Mean experimental τres resulted in 1.2 days which was comprised in the 0.6–2.0 days range estimated by the alternative method. This result brings a noteworthy contribution to the scientific debate about differences among aerosol residence time estimates obtained by different radioactive parent-daughter couple; our results show that the 210Pb/214Bi (or equivalently 210Pb/222Rn) couple provides reliable estimates. © 2020 Elsevier B.V. |
| 英文关键词 | 210Pb; Fine aerosol residence time; Radioactive atmospheric tracers; Radon progeny |
| 语种 | 英语 |
| scopus关键词 | Aerosols; Alpha particle spectrometers; Mixing; Radon; Spectrometry; Atmospheric activity; Atmospheric dispersion; Atmospheric studies; Convective turbulence; Deposition velocities; Mean concentrations; Mixing layer height; Monitoring stations; Atmospheric movements; aerosol composition; aerosol formation; airborne sensing; lead; radon; solar radiation; trace element; Italy; Lombardy; Milan [Milano]; Milano [Lombardy] |
| 来源期刊 | Atmospheric Research
 |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/162039 |
| 作者单位 | Department of Physics, Università degli Studi di Milano, via Celoria 16, Milan, 20133, Italy; National Institute of Nuclear Physics, INFN-Milan, via Celoria 16, Milan, 20133, Italy |
| 推荐引用方式 GB/T 7714 | Crova F.,Valli G.,Bernardoni V.,et al. Effectiveness of airborne radon progeny assessment for atmospheric studies[J],2021,250. |
| APA | Crova F.,Valli G.,Bernardoni V.,Forello A.C.,Valentini S.,&Vecchi R..(2021).Effectiveness of airborne radon progeny assessment for atmospheric studies.Atmospheric Research,250. |
| MLA | Crova F.,et al."Effectiveness of airborne radon progeny assessment for atmospheric studies".Atmospheric Research 250(2021). |
| 条目包含的文件 | 条目无相关文件。 | |||||
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