Annual and interannual variation in boreal forest aerosol particle number and volume concentration and their connection to particle formation

Abstract. We have measured the size distributions of air ions (0.42–7.5 nm in diameter) with the Balanced Scanning Mobility Analyzer in boreal forest, in Southern Finland since spring 2003. The size range covers the size range of cluster ions (approximately 0.42–1.6 nm) and naturally charged nanometre aerosol particles (1.6–7.5 nm) or intermediate air ions. Based on the measurements from April 2003 to March 2006 we studied the characteristics of charged aerosol particle formation by classifying each day either as a particle formation event, undefined or non-event day. The principal of the classification, as well as the statistical description of the charged aerosol particle formation events are given. We found in total 270 (26% of the analysed days) and 226 (22% of the analysed days) particle formation days for negative and positive intermediate ions, respectively. For negatively charged particles we classified 411 (40% of the analysed days) undefined and 348 (34% of the analysed days) non-event days whereas for positively charged particles 343 (33% of the analysed days) undefined and 460 (45% of the analysed days) non-event days. The results were compared with the ordinary classification based on the Differential Mobility Particle Sizer (DMPS) measurements carried out at the same place. The above-presented values differed slightly from that found from the DMPS data, with a lower particle diameter of 3 nm. In addition, we have found the rain-induced intermediate ion bursts frequently. The rain effect was detected on 163 days by means of negative ions and on 105 days by positive ones. Another interesting phenomenon among the charged aerosol particles was the appearance and existence of intermediate ions during the snowfall. We observed this phenomenon 24 times with negatively charged particles and 21 times with positively charged ones during winter months (October–April). These intermediate air ions were seen during the snowfall and may be caused by ice crystals, although the origin of these intermediate ions is unclear at the moment.

Download Full-text

Observations of ultrafine aerosol particle formation and growth in boreal forest

Geophysical Research Letters ◽

10.1029/97gl00920 ◽

1997 ◽

Vol 24 (10) ◽

pp. 1219-1222 ◽

Cited By ~ 225

Author(s):

J. M. Mäkelä ◽

P. Aalto ◽

V. Jokinen ◽

T. Pohja ◽

A. Nissinen ◽

...

Keyword(s):

Boreal Forest ◽

Aerosol Particle ◽

Particle Formation ◽

Ultrafine Aerosol ◽

Particle Formation And Growth

Download Full-text

Occurrence of new particle formation events in Siberian and Finnish boreal forest

10.5194/acp-2021-530 ◽

2021 ◽

Author(s):

Helmi Uusitalo ◽

Jenni Kontkanen ◽

Ilona Ylivinkka ◽

Ekaterina Ezhova ◽

Anastasiia Demakova ◽

...

Keyword(s):

Boreal Forest ◽

Particle Number ◽

Theoretical Calculations ◽

Particle Growth ◽

Particle Formation ◽

Size Distributions ◽

New Particle Formation ◽

Forest Environment ◽

Survival Probabilities ◽

Measured Particle

Abstract. The occurence of new particle formation (NPF) events was investigated at four sites in the boreal forest environment (Hyytiälä SMEAR II and Värriö SMEAR I in Finland; Tomsk-Fonovaya and ZOTTO in Siberia, Russia), by analyzing measured particle number size-distributions (PNSD) and theoretical calculations of particle survival probabilities. NPF events were less frequent at the Siberian sites than at the Finnish sites. This is likely linked to lower survival probabilities of the freshly-formed particles at the Siberian sites, due to higher coagulational losses and lower particle growth rates. Another factor affecting the frequency of observed NPF events is the minimum detectable particle size. When the NPF event classification was made for Hyytiälä, Värriö and Tomsk-Fonovaya sites based on PNSD starting from 15 nm instead of 3 nm, the observed NPF frequencies decreased. This result highlights the importance of measuring PNSD starting from sub-10 nm particles, in order to obtain reliable estimates of the NPF characteristics.

Download Full-text

Characteristics of Aerosol Size Distributions and New Particle Formation Events at Delhi: An Urban Location in the Indo-Gangetic Plains

Frontiers in Earth Science ◽

10.3389/feart.2021.750111 ◽

2021 ◽

Vol 9 ◽

Author(s):

Sandhya Jose ◽

Amit Kumar Mishra ◽

Neelesh K. Lodhi ◽

Sudhir Kumar Sharma ◽

Sachchidanand Singh

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Aerosol Particle ◽

Particle Number ◽

Particle Formation ◽

Number Concentration ◽

New Particle Formation ◽

Nucleation Mode ◽

Aerosol Particle Size

Accurate information about aerosol particle size distribution and its variation under different meteorological conditions are essential for reducing uncertainties related to aerosol-cloud-climate interaction processes. New particle formation (NPF) and the coagulation significantly affect the aerosol size distribution. Here we study the monthly and seasonal variability of aerosol particle size distribution at Delhi from December 2011 to January 2013. Analysis of aerosol particle size distribution using WRAS-GRIMM reveals that aerosol particle number concentration is highest during the post monsoon season owing to the effect of transported crop residue and biomass burning aerosols. Diurnal variations in number concentration show a bimodal pattern with two Aitken mode peaks in all the seasons. Monthly volume size distribution also shows bi-modal distribution with distinct coarse and fine modes. NPF events are observed less frequently in Delhi. Out of 222 days of WRAS data, only 17 NPF events have been observed, with higher NPF frequency during summer season. Growth rate of the nucleation mode of NPF events vary in the range 1.88–21.66 nm/h with a mean value of ∼8.45 ± 5.73 nm/h. It is found that during NPF events the Aitken and nucleation mode particles contribute more to the number concentration. Simultaneous measurement of UV flux and particulate matter (PM10 and PM2.5) have also been done along with particle number size distribution measurement to understand the possible mechanisms for NPF events over the study location.

Download Full-text

Nocturnal aerosol particle formation in the North China Plain

Lithuanian Journal of Physics ◽

10.3952/physics.v55i1.3057 ◽

2015 ◽

Vol 55 (1) ◽

Cited By ~ 9

Author(s):

Simonas Kecorius ◽

Shenglan Zhang ◽

Zhibin Wang ◽

Johannes Größ ◽

Nan Ma ◽

...

Keyword(s):

Aerosol Particle ◽

North China Plain ◽

North China ◽

Particle Number ◽

Formation Rate ◽

Chemical Properties ◽

Particle Formation ◽

New Particle Formation ◽

The North ◽

The North China Plain

New particle formation is one of the major sources of atmospheric aerosol particles. Beside daytime nucleation, nocturnal new particle formation was also found in different regions around the world. Compared with daytime nucleation events, the understanding of nocturnal ones is still sparse. The variety of aerosol particle physico-chemical properties, including particle number size distribution, volatility and hygroscopicity were measured in the North China Plain during July–August 2013. During the observation period, rapid increase in ultrafine particle number concentration was attributed to new particle formation. The nocturnal new particle formation rate was 45 cm–3s–1, which is 1.25 times higher than an observed daytime value. Condensation sink was found to be 0.055 s–1.

Download Full-text

Aerosol particle formation in the Lithuanian hemi-boreal forest

Lithuanian Journal of Physics ◽

10.3952/physics.v58i3.3817 ◽

2018 ◽

Vol 58 (3) ◽

Author(s):

Vadimas Dudoitis ◽

Genrik Mordas ◽

Steigvilė Byčenkienė ◽

Kristina Plauškaitė ◽

Julija Pauraitė ◽

...

Keyword(s):

Boreal Forest ◽

Aerosol Particle ◽

Particle Formation ◽

Particle Nucleation ◽

Forest Environment ◽

Integrated Monitoring ◽

Forest Sites ◽

Total Particle ◽

The Baltic ◽

20 Nm

Aerosol particle observations are needed to determine the conditions of particle formation and growth in different environments. This research focuses on new particle formation (NPF) events in the hemi-boreal forest environment at the Aukštaitija Integrated Monitoring Station (IMS) (55°26ʹN and 26°04ʹE, 170 m above the sea level). The parameterisation of aerosol particle Nucleation I (3–10 nm), Nucleation II (10–20 nm) and Aitken (20–100 nm) modes was performed, their inputs to the total particle number concentration (PNC) and distribution were assessed. It has been estimated that around 40% of days in spring and 22% in summer were NPF event days. The highest contribution of Nucleation mode I aerosol particles was observed in June, reaching up to 38% of the total PNC values. The mean growth rate (GR) and condensation sink (CS) values at the Aukštaitija IMS in April and May were 2.9 nm·h–1, 1.30·10–3 s–1 and 5.3 nm·h–1, 1.35·10–3 s–1, respectively. The GR and CS values were well in agreement with the results obtained from other hemi-boreal forest sites in the Baltic Sea region.

Download Full-text

Identification and classification of the formation of intermediate ions measured in boreal forest

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-9187-2006 ◽

2006 ◽

Vol 6 (5) ◽

pp. 9187-9212

Author(s):

A. Hirsikko ◽

T. Bergman ◽

L. Laakso ◽

M. Dal Maso ◽

I. Riipinen ◽

...

Keyword(s):

Boreal Forest ◽

Aerosol Particle ◽

Size Range ◽

Aerosol Particles ◽

Charged Particles ◽

Negative Ions ◽

Particle Formation ◽

Air Ions ◽

Charged Aerosol ◽

Positively Charged

Abstract. We have measured the size distributions of air ions (0.42–7.5 nm in diameter) with the Balanced Scanning Mobility Analyzer in boreal forest, in Southern Finland since spring 2003. The size range covers the size range of cluster ions (approximately 0.42–1.6 nm) and naturally charged nanometre aerosol particles (1.6–7.5 nm) or intermediate air ions. Based on the measurements from April 2003 to March 2006 we studied the characteristics of charged aerosol particle formation by classifying each day either as a particle formation event, undefined or non-event day. The principal of the classification, as well as the statistical description of the charged aerosol particle formation events are given. We found in total 269 and 226 particle formation days for negative and positive intermediate ions, respectively. For negatively charged particles we classified 411 undefined and 349 non-event days whereas for positively charged particles 342 undefined and 461 non-event days. The results were compared with the ordinary classification based on Differential Mobility Particle Sizer (DMPS) measurements carried out at the same place. The above-presented values differed slightly from that found from the DMPS data, with a lower particle diameter of 3 nm. In addition, we have found the rain-induced intermediate ion bursts frequently. The rain effect was detected on 163 days by means of negative ions and on 104 days by positive ones. Another interesting phenomenon among the charged aerosol particles was the appearance and existence of intermediate ions during the snowfall. We observed this phenomenon 24 times with negatively charged particles and 21 times with positively charged ones during winter months (October–April). These intermediate air ions were seen during the snowfall and may be caused by ice crystals, although the origin of these intermediate ions is unclear at the moment.

Download Full-text