Measuring size distributions of atmospheric aerosols using natural air ions

Li, Yiran; Chen, Xiaotong; Jiang, Jingkun

doi:10.1080/02786826.2022.2060795

Cited by 6 publications

(4 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We compared the NanoScan SMPS with a set of well-calibrated bipolar SMPS as reference. 24 It consisted of a soft X-ray neutralizer (Model 3087, TSI corp.), a long DMA (Model 3081, TSI corp.), and a butanol-based CPC (Model 3772, TSI corp.). The aerosol flow rate is 1 lpm, and the sheath flow rate for the long DMA is 10 lpm and controlled by a homemade sheath flow control box.…”

Section: Methodsmentioning

confidence: 99%

“…It is further demonstrated that since the natural air ions are constantly conditioning the charge state of atmospheric aerosols 23 , it is feasible to retrieve charge fractions of aerosols that are naturally charged and utilize this process to measure size distributions of outdoor aerosols. 24 This new method has been supported by two years of atmospheric measurements, and natural air ions have shown rather stable properties and the capability of replacing conventional neutralizers. These findings lead to a possible solution to the uncertainty brought by unipolar chargers for portable SMPSs.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improving the performance of portable aerosol size spectrometers for building dense monitoring networks

Hao

Jiang

2023

Environ. Sci.: Atmos.

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improving the performance of portable aerosol size spectrometers for building dense monitoring networks

Hao

Jiang

2023

Environ. Sci.: Atmos.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Currently, research on negative air ions primarily focuses on understanding the regularities of their concentration. Mechanistically, the impact of environmental factors, particularly weather conditions, on NAI concentrations is attributed to the state changes within the ions, specifically between large and small ions [38][39][40]. In detail, the horizontal movement of small air ions may lead to a reduction in NAI concentrations through charge transfer from small to large ions, and small ions are considered more beneficial to human health [1,34,[41][42][43][44].…”

Section: Limitations Of This Studymentioning

confidence: 99%

Temporal Dynamics of Negative Air Ion Concentrations in Nanjing Tulou Scenic Area

Li,

Chen

et al. 2024

Atmosphere

View full text Add to dashboard Cite

Negative air ions (NAIs) are crucial for assessing the impact of forests on wellbeing and enhancing the physical and mental health of individuals. They serve as pivotal indicators for assessing air quality. Comprehensive research into the distribution patterns of NAI concentrations, especially the correlation between NAI concentrations and meteorological elements in tourist environments, necessitates the accumulation of additional long-term monitoring data. In this paper, long-term on-site monitoring of NAI concentrations, air temperature, relative humidity, and other factors was conducted in real time over 24 h, from April 2020 to May 2022, to explore the temporal dynamic patterns of NAIs and their influencing factors. The results showed that (1) the daily dynamics of NAI concentrations followed a U-shaped curve. The peak concentrations usually occurred in the early morning (4:30–8:00) and evening (19:10–22:00), and the lowest concentrations usually occurred at noon (12:50–14:45). (2) At the monthly scale, NAI concentrations were relatively high in February, August, and September and low in January, June, and December. At the seasonal scale, NAI concentrations were significantly higher in winter than in other seasons, with higher concentrations occurring in the summer and autumn. (3) Relative humidity, air temperature, and air quality index (AQI) were the primary factors that influenced NAI concentrations. Relative humidity showed a significant positive correlation with NAI concentrations, while air temperature and AQI both exhibited a significant negative correlation with NAI concentrations. Higher air quality corresponds to higher NAI concentrations. Our research provides new insights into NAI temporal dynamics patterns and their driving factors, and it will aid in scheduling outdoor recreation and forest health activities.

show abstract

“…The generated particles were dried and then classified using a DMA with a centroid diameter of 100 nm. Classified particles were neutralized to reach a steady-state charge fraction, which is used to represent the charge fraction of atmospheric particles (Li et al, 2022). These neutralized particles were subsequently injected into the chamber.…”

Section: Laboratory Experimentsmentioning

confidence: 99%

The effectiveness of the coagulation sink of 3–10 nm atmospheric particles

et al. 2022

Self Cite

View full text Add to dashboard Cite

Abstract. As a major source of ultrafine particles, new particle formation (NPF) occurs frequently in various environments. However, the survival of new particles and the frequent occurrence of NPF events in polluted environments have long been perplexing, since new particles are expected to be scavenged by high coagulation sinks. Towards solving these problems, we establish an experimental method and directly measure the effectiveness of the size-dependent coagulation sink of monodisperse 3–10 nm particles in well-controlled chamber experiments. Based on the chamber experiments and long-term atmospheric measurements from Beijing, we then discuss the survival of new particles in polluted environments. In the chamber experiments, the measured coagulation sink of 3–10 nm particles increases significantly with a decreasing particle size, whereas it is not sensitive to the compositions of test particles. Comparison between the measured coagulation coefficient with theoretical predictions shows that almost every coagulation leads to the scavenging of one particle, and the coagulation sink exceeds the hard-sphere kinetic limit due to van der Waals attractive force. For urban Beijing, the effectiveness of the coagulation sink and a moderate or high (e.g., > 3 nm h−1) growth rate of new particles can explain the occurrence of measured NPF events; the moderate growth rate further implies that, in addition to gaseous sulfuric acid, other gaseous precursors also contribute to the growth of new particles.

show abstract

Measuring size distributions of atmospheric aerosols using natural air ions

Cited by 6 publications

References 32 publications

Improving the performance of portable aerosol size spectrometers for building dense monitoring networks

Improving the performance of portable aerosol size spectrometers for building dense monitoring networks

Temporal Dynamics of Negative Air Ion Concentrations in Nanjing Tulou Scenic Area

The effectiveness of the coagulation sink of 3–10 nm atmospheric particles

Contact Info

Product

Resources

About