Air Ion Mobility Research Articles

Performance of a novel charge sensor on the ion detection for the development of a high-pressure avalancheless ion TPC

Within the project of building a time projection chamber using 100 kg of high-pressure 86SeF6 gas to search for the neutrinoless double-beta decay in the NvDEx collaboration, we are developing a CMOS charge sensor, named Topmetal-S, which is tailored for the experiment to detect the ions without gas amplification. In this work, the performance of the sensor is presented. The equivalent noise charge of the sensor is measured to be about 120 to 140 e- depending on the operating point, with the charge injection capacitance calibrated against external capacitors. The signal waveforms are investigated with various chip parameters and experimental settings. In addition to electrons, both negatively and positively charged ions could be detected, and their waveforms are studied using air and SF6 gases. Using the sensor, the mobility of negative ions in ambient air in the atmospheric pressure is measured to be 1.555 ± 0.038 cm2 · V-1 · s-1. Our study demonstrates that the Topmetal-S chip could be used as the ion detection charge sensor for the experiment. Further work is ongoing to reduce the noise of the sensor and to develop a small readout plane with tens of the sensors.

Field-Dependent Reduced Ion Mobilities of Positive and Negative Ions in Air and Nitrogen in High Kinetic Energy Ion Mobility Spectrometry (HiKE-IMS).

In High Kinetic Energy Ion Mobility Spectrometry (HiKE-IMS), ions are formed in a reaction region and separated in a drift region, which is similar to classical drift tube ion mobility spectrometers (IMS) operated at ambient pressure. However, in contrast to the latter, the HiKE-IMS is operated at a decreased background pressure of 10-40 mbar and achieves high reduced electric field strengths of up to 120 Td in both the reaction and the drift region. Thus, the HiKE-IMS allows insights into the chemical kinetics of ion-bound water cluster systems at effective ion temperatures exceeding 1000 K, although it is operated at the low absolute temperature of 45 °C. In this work, a HiKE-IMS with a high resolving power of RP = 140 is used to study the dependence of reduced ion mobilities on the drift gas humidity and the effective ion temperature for the positive reactant ions H3O+(H2O)n, O2+(H2O)n, NO+(H2O)n, NO2+(H2O)n, and NH4+(H2O)n, as well as the negative reactant ions O2-(H2O)n, O3-(H2O)n, CO3-(H2O)n, HCO3-(H2O)n, and NO2-(H2O)n. By varying the reduced electric field strength in the drift region, cluster transitions are observed in the ion mobility spectra. This is demonstrated for the cluster systems H3O+(H2O)n and NO+(H2O)n.

Dependence of the average mobility of ions in air with pressure and humidity

The ion mobility is the one of the basic parameters in the study on gas discharge. There are many environmental parameters affecting the average mobility of ions in air. Among them pressure and humidity are important factors. Until now there is no uniform average mobility of ions in air in practice. This paper presents the results of a series of experiments on the influence of pressure and humidity on the average mobility of ions in air. Firstly, an improved analysis method to deduce the average air ion mobility in air is presented with the help of an apparatus for generating parallel-plane ion flow field. Then, the mobility is measured in a climatic test cabinet. The positive and negative mobilities in the air with the pressure from 80 to 110 kPa and the relative humidity from 20% to 80% at the room temperature are provided. Finally, the rule of mobility-pressure-humidity variation curve is discussed and the specific formula for average mobility of ions in air with respect to pressure and humidity is then raised.

CCN production by new particle formation in the free troposphere

Abstract. Global models predict that new particle formation (NPF) is, in some environments, responsible for a substantial fraction of the total atmospheric particle number concentration and subsequently contributes significantly to cloud condensation nuclei (CCN) concentrations. NPF events were frequently observed at the highest atmospheric observatory in the world, on Chacaltaya (5240 m a.s.l.), Bolivia. The present study focuses on the impact of NPF on CCN population. Neutral cluster and Air Ion Spectrometer and mobility particle size spectrometer measurements were simultaneously used to follow the growth of particles from cluster sizes down to ∼ 2 nm up to CCN threshold sizes set to 50, 80 and 100 nm. Using measurements performed between 1 January and 31 December 2012, we found that 61 % of the 94 analysed events showed a clear particle growth and significant enhancement of the CCN-relevant particle number concentration. We evaluated the contribution of NPF, relative to the transport and growth of pre-existing particles, to CCN size. The averaged production of 50 nm particles during those events was 5072, and 1481 cm−3 for 100 nm particles, with a larger contribution of NPF compared to transport, especially during the wet season. The data set was further segregated into boundary layer (BL) and free troposphere (FT) conditions at the site. The NPF frequency of occurrence was higher in the BL (48 %) compared to the FT (39 %). Particle condensational growth was more frequently observed for events initiated in the FT, but on average faster for those initiated in the BL, when the amount of condensable species was most probably larger. As a result, the potential to form new CCN was higher for events initiated in the BL (67 % against 53 % in the FT). In contrast, higher CCN number concentration increases were found when the NPF process initially occurred in the FT, under less polluted conditions. This work highlights the competition between particle growth and the removal of freshly nucleated particles by coagulation processes. The results support model predictions which suggest that NPF is an effective source of CCN in some environments, and thus may influence regional climate through cloud-related radiative processes.

Inactivation of airborne bacteria by cold plasma in air duct flow

This paper developed a numerical model for predicting bacteria inactivation by cold plasma tube. The bulk air velocity, ion mobility, electric field and ion diffusion were considered in the model to obtain the distribution of negative ions. The sink term appeared in the model was determined by a semi-empirical approach through experiment. A 9-m long, 200 mm square duct was used for carrying out experiments. Negative ion concentration along the duct and inactivation rate of E. coli was measured. Based on the inactivation rate, the sink term was estimated and fed to the model. Three different device installation scenarios were investigated: single plasma unit, two plasma tubes arranged in horizontal and finally two plasma arranged in vertical orientations. The simulation results were agreed well with site measurement of ion intensities as well as pathogen inactivation experiments, an application of cold plasma in a single hospital ward was discussed. The developed model can be applied to advanced disinfection technologies in HVAC systems, besides, the method for modeling the bacteria can be expanded to other microorganisms. Limitations of the model are also discussed.

Air ion mobility spectra and concentrations upwind and downwind of overhead AC high voltage power lines

Corona ions produced by high-voltage power lines (HVPLs) can alter the nearby electrical environment, potentially increasing aerosol charge levels downwind. However, there is a lack of knowledge concerning the concentration and mobility of ions from AC HVPLs and their dispersion away from the line. We present ion concentration and mobility measurements made near AC HVPLs in South-West England. Examples of typical mobility spectra are shown highlighting features commonly observed. Corona was observed during 33 of 46 measurements, at 9 of 11 sites, with positive or ‘bipolar’ (both polarities) ion production commonly seen. Ion production usually increases atmospheric concentrations by only a modest amount, but extreme cases can enhance concentration by an order of magnitude or more. A polarity imbalance is required to increase aerosol charge via ion attachment; this was observed on 15 of 24 days when positive corona was observed, but was not seen for negative ions. Ion mobility was higher downwind compared with upwind for both ion polarities, but the increase was not statistically significant. Future work should focus on identifying and characterising ‘heavy-producing’ HVPLs, and obtaining results in conditions which may favour negative ion production e.g. high humidity, inclement weather or during nighttime.

Measuring drift mobility of organic ions using a drift diode

A new method of measurement of the drift mobility of organic ions in air at atmospheric pressure is proposed that is based on the surface ionization of compounds in a drift diode. Using the proposed method, it is possible to determine the drift mobility of organic ions in air at atmospheric pressure and detect components in mixtures of organic compounds. The drift mobility has been experimentally determined for ions of several nitrogen-containing organic compounds.

Stability and alignment of MCC/IMS devices

There are numerous analytical detection methods available for human breath investigations. Themajor spectrometric methods used are proton transfer reaction mass spectrometry (PRT-MS) [1–5], selected ion flow tube mass spectrometry (SIFT-MS) [6–10], solid phase micro extraction-gas chromatography coupled to mass spectrometry (SPME-GC/ MS) [11–14], and multi-capillary column coupled to ion mobility spectrometry (MCC/IMS) [15–20]. In all cases mentioned, a non–invasive and an easy method for early diagnosis or therapy monitoring are developed by identifying disease-specific biomarkers in the breath of patients. Obviously, if the results of these studies are to be valid, consideration of sampling techniques, and the comparison of the inhaled and the exhaled air are some fundamental requirements. Small changes within the room air can affect the difference between room air and exhaled breath depending on the method selected, for example, patients suffering lung cancer and healthy volunteers. Therefore, in the present paper a study of the stability of two volatiles present in room air ion mobility spectrometry measurements over 6 months is reported, and also the variability of these two volatiles for different MCC/IMS devices is also described. The present paper considers the influence of temperature and other parameters with small variations in the instrumentation. General remarks could be found in [21, 22], the influence of temperature in [23–32], pressure in [33], electric field in [34, 35], carrier gas flow [23, 31], geometrical parameters [36, 37]. Therefore, we discuss the inter-comparison of different instruments. Theoretical aspects and in-depth explanations regarding the operating conditions of the MCC/IMS were discussed in the literature mentioned above. The present paper deals with practical points that are to be considered while intercomparing different instruments and show, that a proper alignment is really needed for such purpose.

Parameterization of ion-induced nucleation rates based on ambient observations

Abstract. Atmospheric ions participate in the formation of new atmospheric aerosol particles, yet their exact role in this process has remained unclear. Here we derive a new simple parameterization for ion-induced nucleation or, more precisely, for the formation rate of charged 2-nm particles. The parameterization is semi-empirical in the sense that it is based on comprehensive results of one-year-long atmospheric cluster and particle measurements in the size range ~1–42 nm within the EUCAARI (European Integrated project on Aerosol Cloud Climate and Air Quality interactions) project. Data from 12 field sites across Europe measured with different types of air ion and cluster mobility spectrometers were used in our analysis, with more in-depth analysis made using data from four stations with concomitant sulphuric acid measurements. The parameterization is given in two slightly different forms: a more accurate one that requires information on sulfuric acid and nucleating organic vapor concentrations, and a simpler one in which this information is replaced with the global radiation intensity. These new parameterizations are applicable to all large-scale atmospheric models containing size-resolved aerosol microphysics, and a scheme to calculate concentrations of sulphuric acid, condensing organic vapours and cluster ions.

EUCAARI ion spectrometer measurements at 12 European sites – analysis of new particle formation events

Abstract. We present comprehensive results on continuous atmospheric cluster and particle measurements in the size range ~1–42 nm within the European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) project. We focused on characterizing the spatial and temporal variation of new particle formation events and relevant particle formation parameters across Europe. Different types of air ion and cluster mobility spectrometers were deployed at 12 field sites across Europe from March 2008 to May 2009. The measurements were conducted in a wide variety of environments, including coastal and continental locations as well as sites at different altitudes (both in the boundary layer and the free troposphere). New particle formation events were detected at all of the 12 field sites during the year-long measurement period. From the data, nucleation and growth rates of newly formed particles were determined for each environment. In a case of parallel ion and neutral cluster measurements, we could also estimate the relative contribution of ion-induced and neutral nucleation to the total particle formation. The formation rates of charged particles at 2 nm accounted for 1–30% of the corresponding total particle formation rates. As a significant new result, we found out that the total particle formation rate varied much more between the different sites than the formation rate of charged particles. This work presents, so far, the most comprehensive effort to experimentally characterize nucleation and growth of atmospheric molecular clusters and nanoparticles at ground-based observation sites on a continental scale.

Modeling of Saturation Characteristic of an Aspiration Condenser

It was conflrmed that light air ions have positive in∞uence on human health. For its appraisal it is necessary to know the concentration of air ions and air ion mobility spectrum. This spectrum is usually found out using the saturation characteristic measurement with a ger- dien tube; another design option consists in the aspiration condenser with a segmented inner electrode. The second method is faster, but the resolution of air ion mobility spectrum shows worse characteristics.. This paper deals with the mathematical analysis and numerical model- ing of saturation characteristic evaluation for this aspiration condenser with a segmented inner electrode. Using a combination of both methods may increase the resolution of air ion mobility spectrum, and the progress of measurement is still better than with the gerdien tube solution. The presumption that ions contained it the air have signiflcant in∞uence on living organisms has been discussed in a large number of scientiflc papers with a focus on the problem of concrete efiects of ions on bacteria, animals, and humans (1{3). Light and negative ions feature positive efiects on the human organism, whereas their heavy and positive counterparts bring about negative impact. It was shown by N. I. Goldshtein (3) that the complete absence of negative air ions in the inhaled air is fatal to animals. Any evaluation of air ions and their impact on the human organism is only made possible after and on the basis of air ions concentration measurement and air ions spectrum mobility. One of its methods is based on measurement using the aspiration capacitor. In a simple aspiration condenser | gerdien tube the internal electrode is not divided into several segments. This method will be modeled saturation characteristics for the natural spectrum of negative air ions measured in (4). Here, the disadvantage consists in considerable time consumption inherent with the measurement of air ions spectrum. However, if an aspiration condenser with a segmented inner electrode is applied, the pace of measurement can be substantially accelerated. We will obtain an estimation of the air ions spectrum in the given interval, whose accuracy can be further advanced by measurement at several voltages. For the purpose, saturation characteristics will be modeled again of individual segments of the aspiration condenser inner electrode. 2. THE ASPIRATION METHOD PRINCIPLE The basic principle of the aspiration method is shown in Fig. 1 on an elementary aspiration con- denser | gerdien tube; the principle (model) was taken over from (1) and (5). Here, it holds that d1 | inner electrode diameter, d2 | outer electrode diameter, L | length of gerdien tube, vx | air ∞ow velocity, \+ | positive air particle (ion), \i | negative air particle (ion). The gerdien tube consists of two electrodes. There is an electric fleld between the inner electrode (the collector) and the outer electrode. The fleld is imposed by voltage source U. The air mass with ions is actuated by a fan through the gerdien tube. Negative ions in the electric fleld impact the collector, and the current produced is measured by an electrometer. The measured current is proportional to air ion concentration (2). By means of the change of polarity it is also possible to measure positive air ions.

Characteristic features of air ions at Mace Head on the west coast of Ireland

Coastal nucleation events and behavior of cluster ions were characterized through the measurements of air ion mobility distributions at the Mace Head research station on the west coast of Ireland in 2006. We measured concentrations of cluster ions and charged aerosol particles in the size range of 0.34–40 nm. These measurements allow us to characterize freshly nucleated charged particles with diameters smaller than 3 nm. The analysis shows that bursts of intermediate ions (1.6–7 nm) are a frequent phenomenon in the marine coastal environment. Intermediate ion concentrations were generally close to zero, but during some nucleation episodes the concentrations increased to several hundreds per cm 3. Nucleation events occurred during most of the measurement days. We classified all days into one of seven classes according to the occurrence and type of new particle formation. Nucleation events were observed during 207 days in 2006, most prominently in the spring and summer months. Rain-induced events, in turn, were observed during 132 days. Particle formation and growth events mostly coincided with the presence of low tide. Also small cluster ions (0.34–1.6 nm) were characterized. Average concentrations of small ions were 440 cm − 3 for the negative ions and 423 cm − 3 for the positive ions. Average mean mobilities of small ions were 1.86 cm 2V − 1 s − 1 and 1.49 cm 2V − 1 s − 1 for the negative and positive polarities, respectively. Concentrations of small ions were observed to be strongly dependent on the variations of meteorological parameters including wind speed and direction.

Charging state of atmospheric nanoparticles during the nucleation burst events

In this work, the charging state of atmospheric nanoparticles was estimated through simultaneous measurements of aerosol size distribution and air ions mobility distribution with the aim to elucidate the formation mechanisms of atmospheric aerosols. The measurements were performed as a part of the QUEST 2 campaign at a boreal forest station in Finland. The overlapping part of the measurement ranges of the particle size spectrometers and air ion mobility spectrometers in the mass diameter interval of 2.6–40 nm was used to assess the percentage of charged particles (charging probability). This parameter was obtained as the slope of the linear regression line on the scatterplot of the measured concentrations of total (neutral + charged) and charged particles for the same diameter interval. Charging probabilities as a function of particle diameter were calculated for different days and were compared with the steady state charging probabilities of the particles in the bipolar ion atmosphere. For the smallest particles detectable by the particle size spectrometers (2.6–5 nm), the high percentages of negatively charged particles were found during the nanometer particle concentration bursts. These values considerably exceeded the values for the steady charging state and it was concluded that negative cluster ions preferably act as condensation nuclei. This effect was found to be the highest in the case of comparatively weak nucleation bursts of nanoparticles, when the rate of the homogeneous nucleation and the concentration of freshly nucleated particles were low. The nucleation burst days were classified according to the concentration of the generated smallest detectable new particles (weak and strong bursts). Approximately the same classification was obtained based on the charge asymmetry on particles with respect to the charge sign (polarity). The probabilities of negative and positive charge on the particles with the diameter of 5–20 nm were found to be nearly equal and they approximately agree with the values corresponding to the steady state charge distribution for negative particles known from lab experiments. It means that the steady charging state was reached during the growing time of particles up to 5 nm. The natural charging state of particles with a diameter between 2.5 and 4.5 nm was estimated by means of a special DMPS setup. Results were found to be in good correlation with the data by the particle size spectrometers and air ion mobility spectrometers.

Aspirated capacitor measurements of air conductivity and ion mobility spectra

Measurements of ions in atmospheric air are used to investigate atmospheric electricity and particulate pollution. Commonly studied ion parameters are (1) air conductivity, related to the total ion number concentration, and (2) the ion mobility spectrum, which varies with atmospheric composition. The physical principles of air ion instrumentation are long established. A recent development is the computerized aspirated capacitor, which measures ions from (a) the current of charged particles at a sensing electrode, and (b) the rate of charge exchange with an electrode at a known initial potential, relaxing to a lower potential. As the voltage decays, only ions of higher and higher mobility are collected by the central electrode and contribute to the further decay of the voltage. This enables extension of the classical theory to calculate ion mobility spectra by inverting voltage decay time series. In indoor air, ion mobility spectra determined from both the voltage decay inversion, and an established voltage switching technique, were compared and shown to be of similar shape. Air conductivities calculated by integration were: 5.3±2.5 and 2.7±1.1fSm−1, respectively, with conductivity determined to be 3fSm−1 by direct measurement at a constant voltage. Applications of the relaxation potential inversion method include air ion mobility spectrum retrieval from historical data, and computation of ion mobility spectra in planetary atmospheres.

Ion production rate in a boreal forest based on ion, particle and radiation measurements

Abstract. In this study the ion production rates in a boreal forest were studied based on two different methods: 1) cluster ion and particle concentration measurements, 2) external radiation and radon concentration measurements. Both methods produced reasonable estimates for ion production rates. The average ion production rate calculated from aerosol particle size distribution and air ion mobility distribution measurements was 2.6 ion pairs cm-3s-1, and based on external radiation and radon measurements, 4.5 ion pairs cm-3s-1. The first method based on ion and particle measurements gave lower values for the ion production rates especially during the day. A possible reason for this is that particle measurements started only from 3nm, so the sink of small ions during the nucleation events was underestimated. It may also be possible that the hygroscopic growth factors of aerosol particles were underestimated. Another reason for the discrepancy is the nucleation mechanism itself. If the ions are somehow present in the nucleation process, there could have been an additional ion sink during the nucleation days.

Comparative study of nucleation mode aerosol particles and intermediate air ions formation events at three sites

Quantitative characteristics of the formation and growth events of nucleation mode aerosol particles occurred at three stations (Hyytiälä and Värriö in Finland and Tahkuse in Estonia) have been compared. Aerosol size distributions were measured on all locations and, in addition, air ion mobility distribution at Tahkuse. Among 157 measuring days, nucleation events were identified on 62, 50, and 45 days at Hyytiälä, Värriö, and Tahkuse, respectively. Eighteen days were found when nucleation events occurred on all three locations at the same day. The concentration of condensable vapor, its source strength, the growth rate, the total condensation sink, the formation rate of 3 nm particles, the formation rate, and concentration of 1 nm particles were estimated using measured aerosol number size distributions. The estimated growth rates were in the range of 2–9 nm hr−1. The growth rates found from the measurements of air ion mobility distributions were comparable with that of nanometer particles. The condensable vapor concentrations were 1–12 × 107 cm−3, which is smaller at Hyytiälä than at Tahkuse and Värriö. At Tahkuse, source rates 6–55 × 104 cm−3s−1 were estimated, whereas at Hyytiälä and Värriö the rates were 2–14 × 104 cm−3s−1 and 1–20 × 104 cm−3s−1, respectively. The condensation sink values were usually substantially higher at Tahkuse than on the other locations. Tahkuse size distribution data showed 5–10% underestimates in the total condensation sink considering particles in the diameter range <500 nm. At Tahkuse the charged fraction of nucleation mode particles estimated through comparison of aerosol size distribution and air ion mobility distribution turned to be much higher than steady state charging probability of a single charge on the particle. Analysis of air mass trajectories and meteorological data indicated that the nucleation events are synoptic‐scale phenomenon occurring in horizontal extent more than 1000 km.

Calculation of ion mobilities from electrospray ionization high-field asymmetric waveform ion mobility spectrometry mass spectrometry

Careful analysis is made of the accuracies possible when gaseous ion mobilities are determined from data obtained by combining electrospray ionization (ESI), high-field asymmetric waveform ion mobility spectrometry (FAIMS) at atmospheric pressure and room temperature, and mass spectrometry (MS). New results are reported for the mobilities of positive and negative amino acid ions in air at elevated values of E/N, the ratio of the electric field strength to the gas number density.

Statistical characterization of air ion mobility spectra at Tahkuse Observatory: Classification of air ions

A database of 8615 hourly averaged air ion mobility spectra in the range of 0.00041–3.2 cm2 V−1 s−1 was measured at Tahkuse Observatory, Estonia, during 14 months in 1993–1994. The average mobility spectrum over the whole period shows distinct peaks of small and large ions. Intermediate ions with mobilities of 0.034–0.5 cm2 V−1 s−1 are of low concentration of about 50 cm−3 in the average spectrum. They experience occasional bursts of up to about 900 cm−3 during 6–10 hours at daytime. The number of burst events recorded during 14 months was 101, with maximum frequency in spring and minimum frequency in winter. Physically, large and intermediate ions can be called aerosol ions, and small ions can be called cluster ions. The principal component analysis was applied to detect the structure of an air ion mobility spectrum. As a result, the mobility spectrum in the range of 0.00041–3.2 cm2 V−1 s−1 (diameters of 0.36–79 nm) was divided into five classes: small cluster, big cluster, intermediate, light large, and heavy large ions. The boundaries between the classes are 1.3 cm2 V−1 s−1 (diameter of 0.85 nm), 0.5 cm2 V−1 s−1 (1.6 nm), 0.034 cm2 V−1 s−1 (7.4 nm), and 0.0042 cm2 V−1 s−1 (22 nm). The five principal components that are closely correlated with the respective ion classes explain 92% of total variance. The classification of aerosol ions is in accord with the three‐modal structure of the size spectrum of submicron aerosol particles.

Temperature variation of the evolution of positive small air ions at constant relative humidity

The evolution of positive air ions is mathematically simulated considering 150 trace gases and more than a thousand ion-molecule reactions. The main attention is paid to the evolution of near-ground air ions in the age interval from 10 ms to 3 s where the knowledge about ion evolution is most limited. Recently, detailed experimental data about the time variation of the air ion mobility spectrum became available, and the results of mathematical simulation can be compared with the observed transformations. Unfortunately, the ion mobility measurements have not been accompanied by data about concentrations of the trace gases; therefore the mobilities can be interpreted only ambiguously. Nevertheless, the main features of the measured evolution shape of ions can be explained by the results of simulation, and the best agreement is achieved by the assumption of an enhanced concentration of either acetone or pyridine. In this case, the younger ions should be mainly ions H3O+(H2O)n, while the more aged ions should be either acetone or pyridine family clusters.

Variability in aerosol and air ion composition in the Arctic spring atmosphere

Systematic measurement results of aerosol dispersity in the size range from 0.004 to 10 μm in diameter, element composition, and the mobility spectrum of atmospheric ions in the range from 0.00032 to 5 cm 2/V s in the surface atmospheric layer at Zigler Island (Western Arctic, Franz–Joseph Archipelago, March–April 1994) are presented. A comparison is made with data obtained using similar methods and instruments at Wrangel Island (Eastern Arctic, March–April 1985), in Antarctica (Molodezhnaya station, January–May 1983), over the Pamir mountains (Fedchenko glacier, September 1989) and in the vicinity of Moscow (Obninsk, April–May 1994)). The form and variability of the aerosol size and air ion mobility spectra at different regions of the Arctic and Antarctic, as well as in mountain and forest steppe regions, do not differ significantly. The stratification of the atmospheric boundary layer and wind speed are the main factors of variability of the arctic aerosols and ions. Inflows of air from the mainland do not change these positions.