scholarly journals Analysis of particle size distribution changes between three measurement sites in Northern Scandinavia

2013 ◽  
Vol 13 (4) ◽  
pp. 9401-9442 ◽  
Author(s):  
R. Väänänen ◽  
E.-M. Kyrö ◽  
T. Nieminen ◽  
N. Kivekäs ◽  
H. Junninen ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Aerosol Particle ◽  
Particle Growth ◽  
Particle Formation ◽  
Aerosol Size Distribution ◽  
New Particle Formation ◽  
Air Masses ◽  
Aerosol Dynamics ◽  
Particle Sizer

Abstract. We investigated atmospheric aerosol particle dynamics in a boreal forest zone in Northern Scandinavia. We used aerosol size distribution data measured with either a Differential Mobility Particle Sizer (DMPS) or Scanning Mobility Particle Sizer (SMPS) at three stations (Värriö, Pallas and Abisko), and combined these data with the HYSPLIT air mass trajectory analysis. We compared three approaches: analysis of new particle formation events, investigation of air masses transport from the ocean to individual stations with different over-land transport times, and analysis of changes in aerosol particle size distributions during the air masses transport from one measurement station to another. Aitken mode particles were found to have an apparent average growth rate of 0.6–0.7 nm h−1 when the air masses travelled over land. Particle growth rates during the NPF events were 3–6 times higher than the apparent particle growth. When comparing aerosol dynamics between the different stations for different over-land transport times, no major differences were found except that in Abisko the new particle formation events were observed to take place in air masses having shorter over-land times than at the other stations. We speculate that this is related to the meteorological differences along the paths of air masses caused by the land surface topology. When comparing between air masses travelling the east-to-west direction to those traveling the west-to-east directions, clear differences in the aerosol dynamics were seen. Our results suggest that the condensation growth has an important role in aerosol dynamics also when new particle formation is not evident.

scholarly journals Quantifying aerosol size distributions and their temporal variability in the Southern Great Plains, USA

2019 ◽  
Vol 19 (18) ◽  
pp. 11985-12006 ◽  
Author(s):  
Peter J. Marinescu ◽  
Ezra J. T. Levin ◽  
Don Collins ◽  
Sonia M. Kreidenweis ◽  
Susan C. van den Heever
Keyword(s):  
Size Distribution ◽  
Great Plains ◽  
Diurnal Cycle ◽  
Particle Formation ◽  
Aerosol Size Distribution ◽  
Size Distributions ◽  
New Particle Formation ◽  
Scanning Mobility Particle Sizer ◽  
Southern Great Plains ◽  
Particle Sizer

Abstract. A quality-controlled, 5-year dataset of aerosol number size distributions (particles with diameters (Dp) from 7 nm through 14 µm) was developed using observations from a scanning mobility particle sizer, aerodynamic particle sizer, and a condensation particle counter at the Department of Energy's Southern Great Plains (SGP) site. This dataset was used for two purposes. First, typical characteristics of the aerosol size distribution (number, surface area, and volume) were calculated for the SGP site, both for the entire dataset and on a seasonal basis, and size distribution lognormal fit parameters are provided. While the median size distributions generally had similar shapes (four lognormal modes) in all the seasons, there were some significant differences between seasons. These differences were most significant in the smallest particles (Dp<30 nm) and largest particles (Dp>800 nm). Second, power spectral analysis was conducted on this long-term dataset to determine key temporal cycles of total aerosol concentrations, as well as aerosol concentrations in specified size ranges. The strongest cyclic signal was associated with a diurnal cycle in total aerosol number concentrations that was driven by the number concentrations of the smallest particles (Dp<30 nm). This diurnal cycle in the smallest particles occurred in all seasons in ∼50 % of the observations, suggesting a persistent influence of new particle formation events on the number concentrations observed at the SGP site. This finding is in contrast with earlier studies that suggest new particle formation is observed primarily in the springtime at this site. The timing of peak concentrations associated with this diurnal cycle was shifted by several hours depending on the season, which was consistent with seasonal differences in insolation and boundary layer processes. Significant diurnal cycles in number concentrations were also found for particles with Dp between 140 and 800 nm, with peak concentrations occurring in the overnight hours, which were primarily associated with both nitrate and organic aerosol cycles. Weaker cyclic signals were observed for longer timescales (days to weeks) and are hypothesized to be related to the timescales of synoptic weather variability. The strongest periodic signals (3.5–5 and 7 d cycles) for these longer timescales varied depending on the season, with no cyclic signals and the lowest variability in the summer.

scholarly journals New particle formation in air mass transported between two measurement sites in Northern Finland

2005 ◽  
Vol 5 (6) ◽  
pp. 11929-11963 ◽  
Author(s):  
M. Komppula ◽  
S.-L. Sihto ◽  
H. Korhonen ◽  
H. Lihavainen ◽  
V.-M. Kerminen ◽  
...  
Keyword(s):  
Growth Rates ◽  
Particle Growth ◽  
Particle Formation ◽  
Distribution Data ◽  
New Particle Formation ◽  
Air Mass ◽  
Air Masses ◽  
Aerosol Dynamics ◽  
Almost All ◽  
Distinct Features

Abstract. This study covers four years of aerosol number size distribution data from Pallas and Värriö sites 250 km apart from each other in Northern Finland and compares new particle formation events between these sites. In eastern air masses almost all events were observed to start earlier at the eastern station Värriö, whereas in western air masses most of the events were observed to start earlier at the western station Pallas. This demonstrates that particle formation in a certain air mass type depends not only on the diurnal variation of the parameters causing the phenomenon (such as photochemistry) but also on some properties carried by the air mass itself. The correlation in growth rates between the two sites was relatively good, which suggests that the amount of condensable vapour causing the growth must have been at about the same level in both sites. The value of condensation sink was frequently much higher at the downwind station. It seems that secondary particle formation related to biogenic sources dominate in many cases over the particle sinks during the air mass transport between the sites. Two cases of transport from Pallas to Värriö were further analysed with an aerosol dynamics model. The model was able to reproduce the observed nucleation events 250 km down-wind at Värriö but revealed some differences between the two cases. The simulated nucleation rates were in both cases similar but the organic concentration profiles that best reproduced the observations were different in the two cases indicating that divergent formation reactions may dominate under different conditions. The simulations also suggested that organic compounds were the main contributor to new particle growth, which offers a tentative hypothesis to the distinct features of new particles at the two sites: Air masses arriving from Atlantic Ocean typically spent approximately only ten hours over land before arriving at Pallas, and thus the time for the organic vapours to accumulate in the air and to interact with the particles is relatively short. This can lead to low nucleation mode growth rates and even to suppression of detectable particle formation event due to efficient scavenging of newly formed clusters, as was observed in the case studies.

Airborne observations of the effect of a cold front on the aerosol particle size distribution and new particle formation

2010 ◽  
Vol 136 (649) ◽  
pp. 944-961 ◽  
Author(s):  
Justin R. Peter ◽  
Steven T. Siems ◽  
Jørgen B. Jensen ◽  
John L. Gras ◽  
Yutaka Ishizaka ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Aerosol Particle ◽  
Cold Front ◽  
Particle Formation ◽  
New Particle Formation ◽  
Aerosol Particle Size

scholarly journals Classifying previously undefined days from eleven years of aerosol-particle-size distribution data from the SMEAR II station, Hyytiälä, Finland

2009 ◽  
Vol 9 (2) ◽  
pp. 667-676 ◽  
Author(s):  
S. Buenrostro Mazon ◽  
I. Riipinen ◽  
D. M. Schultz ◽  
M. Valtanen ◽  
M. Dal Maso ◽  
...  
Keyword(s):  
Particle Size ◽  
Relative Humidity ◽  
Size Distribution ◽  
Aerosol Particle ◽  
Particle Formation ◽  
Number Concentration ◽  
Aerosol Size Distribution ◽  
Distribution Data ◽  
Back Trajectories ◽  
Condensation Sink

Abstract. Studies of secondary aerosol-particle formation depend on identifying days in which new particle formation occurs and, by comparing them to days with no signs of particle formation, identifying the conditions favourable for formation. Continuous aerosol size distribution data has been collected at the SMEAR II station in a boreal forest in Hyytiälä, Finland, since 1996, making it the longest time series of aerosol size distributions available worldwide. In previous studies, the data have been classified as particle-formation event, nonevent, and undefined days, with almost 40% of the dataset classified as undefined. In the present study, eleven years (1996–2006) of undefined days (1630 days) were reanalyzed and subdivided into three new classes: failed events (37% of all previously undefined days), ultrafine-mode concentration peaks (34%), and pollution-related concentration peaks (19%). Unclassified days (10%) comprised the rest of the previously undefined days. The failed events were further subdivided into tail events (21%), where a tail of a formation event presumed to be advected to Hyytiälä from elsewhere, and quasi events (16%) where new particles appeared at sizes 3–10 nm, but showed unclear growth, the mode persisted for less than an hour, or both. The ultrafine concentration peaks days were further subdivided into nucleation-mode peaks (24%) and Aitken-mode peaks (10%), depending on the size range where the particles occurred. The mean annual distribution of the failed events has a maximum during summer, whereas the two peak classes have maxima during winter. The summer minimum previously found in the seasonal distribution of event days partially offsets a summer maximum in failed-event days. Daily-mean relative humidity and condensation sink values are useful in discriminating the new classes from each other. Specifically, event days had low values of relative humidity and condensation sink relative to nonevent days. Failed-event days possessed intermediate condensation sink and relative humidity values, whereas both ultrafine-mode peaks and, to a greater extent, pollution-related peaks had high values of both, similar to nonevent days. Using 96-h back trajectories, particle-size concentrations were plotted as a function of time the trajectory spent over land. Increases in particle size and number concentration during failed-event days were similar to that during the later stages of event days, whereas the particle size and number concentration for both nonevent and peaks classes did not increase as fast as for event and failed events days.

scholarly journals New Particle Formation and Sub-10 nm Size Distribution Measurements during the A-LIFE field experiment in Paphos, Cyprus

2019 ◽  
Author(s):  
Sophia Brilke ◽  
Nikolaus Fölker ◽  
Thomas Müller ◽  
Konrad Kandler ◽  
Xianda Gong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Field Experiment ◽  
Size Distribution ◽  
Particle Formation ◽  
Atmospheric Environment ◽  
Aerosol Size Distribution ◽  
Initial Growth ◽  
New Particle Formation ◽  
Nucleation Mode

Abstract. Atmospheric particle size distributions were measured in Paphos, Cyprus, during the A-LIFE (Absorbing aerosol layers in a changing climate: aging, lifetime and dynamics) field experiment from April 3–30, 2017. The newly developed DMA-train is deployed for the first time in an atmospheric environment for the direct measurement of the nucleation mode size range between 1.8–10 nm diameter. The DMA-train setup consists of seven size channels, of which five are set to fixed particle mobility diameters and two additional diameters are obtained by alternating voltage settings in one DMA every 10 s. In combination with a conventional Mobility Particle Size Spectrometer (MPSS) and an Aerodynamic Particle Sizer (APS) the complete atmospheric aerosol size distribution from 1.8 nm–10 µm is covered. The focus of the A-LIFE study is to characterize new particle formation (NPF) in the Eastern Mediterranean region at a measurement site with strong local pollution sources. The nearby Paphos airport was found to be a large emission source for nucleation mode particles and we analysed the size distribution of the airport emission plumes at approximately 500 m from the main runway. The analysis yielded 9 NPF events in 27 measurement days from the combined analysis of the DMA-train, MPSS and trace gas monitors. Growth rate calculations were performed and a size-dependency of the initial growth rate (

scholarly journals New particle formation in air mass transported between two measurement sites in Northern Finland

2006 ◽  
Vol 6 (10) ◽  
pp. 2811-2824 ◽  
Author(s):  
M. Komppula ◽  
S.-L. Sihto ◽  
H. Korhonen ◽  
H. Lihavainen ◽  
V.-M. Kerminen ◽  
...  
Keyword(s):  
Growth Rates ◽  
Particle Growth ◽  
Particle Formation ◽  
Distribution Data ◽  
New Particle Formation ◽  
Air Mass ◽  
Air Masses ◽  
Aerosol Dynamics ◽  
Almost All ◽  
Distinct Features

Abstract. This study covers four years of aerosol number size distribution data from Pallas and Värriö sites 250 km apart from each other in Northern Finland and compares new particle formation events between these sites. In air masses of eastern origin almost all events were observed to start earlier at the eastern station Värriö, whereas in air masses of western origin most of the events were observed to start earlier at the western station Pallas. This demonstrates that particle formation in a certain air mass type depends not only on the diurnal variation of the parameters causing the phenomenon (such as photochemistry) but also on some properties carried by the air mass itself. The correlation in growth rates between the two sites was relatively good, which suggests that the amount of condensable vapour causing the growth must have been at about the same level in both sites. The condensation sink was frequently much higher at the downwind station. It seems that secondary particle formation related to biogenic sources dominate in many cases over the particle sinks during the air mass transport between the sites. Two cases of transport from Pallas to Värriö were further analysed with an aerosol dynamics model. The model was able to reproduce the observed nucleation events 250 km down-wind at Värriö but revealed some differences between the two cases. The simulated nucleation rates were in both cases similar but the organic concentration profiles that best reproduced the observations were different in the two cases indicating that divergent formation reactions may dominate under different conditions. The simulations also suggested that organic compounds were the main contributor to new particle growth, which offers a tentative hypothesis to the distinct features of new particles at the two sites: Air masses arriving from the Atlantic Ocean typically spent approximately only ten hours over land before arriving at Pallas, and thus the time for the organic vapours to accumulate in the air and to interact with the particles is relatively short. This can lead to low nucleation mode growth rates and even to suppression of detectable particle formation event due to efficient scavenging of newly formed clusters, as was observed in the case studies.

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

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.

scholarly journals Analysis of particle size distribution changes between three measurement sites in northern Scandinavia

2013 ◽  
Vol 13 (23) ◽  
pp. 11887-11903 ◽  
Author(s):  
R. Väänänen ◽  
E.-M. Kyrö ◽  
T. Nieminen ◽  
N. Kivekäs ◽  
H. Junninen ◽  
...  
Keyword(s):  
Mass Transport ◽  
Aerosol Particle ◽  
Growth Rates ◽  
Particle Number ◽  
Particle Growth ◽  
Size Distributions ◽  
Air Mass ◽  
Air Masses ◽  
Aerosol Dynamics ◽  
Particle Sizer

Abstract. We investigated atmospheric aerosol particle dynamics in a boreal forest zone in northern Scandinavia. We used aerosol number size distribution data measured with either a differential mobility particle sizer (DMPS) or scanning mobility particle sizer (SMPS) at three stations (Värriö, Pallas and Abisko), and combined these data with the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) air mass trajectory analysis. We compared three approaches: analysis of new particle formation events, investigation of aerosol particle number size distributions during the air mass transport from the ocean to individual stations with different overland transport times, and analysis of changes in aerosol particle number size distributions during the air mass transport from one measurement station to another. Aitken-mode particles were found to have apparent average growth rates of 0.6–0.7 nm h−1 when the air masses traveled over land. Particle growth rates during the new particle formation (NPF) events were 3–6 times higher than the apparent particle growth during the summer period. When comparing aerosol dynamics for different overland transport times between the different stations, no major differences were found, except that in Abisko the NPF events were observed to take place in air masses with shorter overland times than at the other stations. We speculate that this is related to the meteorological differences along the paths of air masses caused by the land surface topology. When comparing air masses traveling in an east-to-west direction with those traveling in a west-to-east direction, clear differences in the aerosol dynamics were seen. Our results suggest that the condensation growth has an important role in aerosol dynamics even when NPF is not evident.

scholarly journals Multicomponent aerosol dynamics model UHMA: model development and validation

2004 ◽  
Vol 4 (1) ◽  
pp. 471-506 ◽  
Author(s):  
H. Korhonen ◽  
K. E. J. Lehtinen ◽  
M. Kulmala
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Volume Fraction ◽  
Particle Formation ◽  
Time Interval ◽  
New Particle Formation ◽  
Dynamics Model ◽  
Aerosol Dynamics ◽  
Tropospheric Aerosol

Abstract. A size-segregated aerosol dynamics model UHMA (University of Helsinki Multicomponent Aerosol model) was developed for studies of multicomponent tropospheric aerosol particles. The model includes major aerosol microphysical processes in the atmosphere with a focus on new particle formation and growth; thus it incorporates particle coagulation and multicomponent condensation, applying a revised treatment of condensation flux onto free molecular regime particles and the activation of nanosized clusters by organic vapours (Nano-Köhler theory), as well as recent parameterizations for binary H2SO4–H2O and ternary H2SO4–NH3-H2O homogeneous nucleation and dry deposition. The representation of particle size distribution can be chosen from three sectional methods: the hybrid method, the moving center method, and the retracking method in which moving sections are retracked to a fixed grid after a certain time interval. All these methods can treat particle emissions and transport consistently, and are therefore suitable for use in large scale atmospheric models. In a test simulation against an accurate high resolution solution, all the methods showed reasonable treatment of new particle formation with 20 size sections although the hybrid and the retracking methods suffered from artificial widening of the distribution. The moving center approach, on the other hand, showed extra dents in the particle size distribution and failed to predict the onset of detectable particle formation. In a separate test simulation of an observed nucleation event, the model captured the key qualitative behaviour of the system well. Furthermore, its prediction of the organic volume fraction in newly formed particles, suggesting values as high as 0.5 for 3–4 nm particles and approximately 0.8 for 10 nm particles, agrees with recent indirect composition measurements.

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