Thermodynamics is applied to formulate general equations for internal energies and grand potential for a system consisting of a dielectric liquid nucleus of a new phase on a charged insoluble conducting sphere within a uniform macroscopic one- or …
Based on the results of a previous paper [M. Noppel, H. Vehkamaki, P. M. Winkler, M. Kulmala, and P. E. Wagner, J. Chem. Phys. 139, 134107 (2013)], we derive a thermodynamically consistent expression for reversible or minimal work needed to form a …
Continuous measurements of intermediate air ion size distributions were carried out in the small town Tartu, Estonia, from 1 April 2010 through 7 November 2011. The intermediate ions are charged aerosol particles of diameter 1.5-7.5 nm. In this paper …
The paper describes the Neutral cluster and Air Ion Spectrometer (NAIS) - a multichannel aerosol instrument capable of measuring the distribution of ions (charged particles and cluster ions) of both polarities in the electric mobility range from 3.2 …
South Africa holds significant mineral resources, with a substantial fraction of these reserves occurring and being processed in a large geological structure termed the Bushveld Igneous Complex (BIC). The area is also highly populated by informal, …
In order to explore an additional window to look into the mechanisms behind atmospheric ion and particle formation, an advanced method, which combines the study of ageing of air ions by both mobility and mass spectrometry is developed and examined. …
We have, since 2007, continuously measured the electrical mobility distribution of small (<1.5 nm in diameter) corona-generated one-second-aged air ions, using our Small Air Ion Spectrometer (KAIS), in urban area, in the center of the town of Tartu, Estonia. We have simultaneously measured the mobility distributions of natural air ions (0.42-7.4 nm in diameter) with the Balanced Scanning Mobility Analyzer (BSMA). In this work we employ these data to establish certain links between the concurrent spectra of two types, especially for days with new particle formation events. We elaborated and tested an automatic classification method, which selected the spectra according their shape. In the case of the BSMA negative ions, we obtained four classes of the spectra which are associated with the intermediate ion (1.6-7.4 nm in diameter) nucleation burst events and rain-type events. The spectra within these classes are characterized by special shapes and they are called ``event-like spectra″. The first class demonstrates the strongest increase in the concentration of all ions with the mobilities below 0.8 cm(2)V(-1) s(-1) (above 1.25 nm in diameter), it mainly contains spring and early summer spectra, recorded around midday. In the second class, the events are weaker; it contains a large number of late spring morning time spectra, when relative humidity (RH) tends to decrease. The third and the fourth classes contain many spectra, which resemble to short isolated events. These spectra are excluded from the further analysis. In the first class, the precipitation spectra make about 34% of all the event-like spectra, in the other classes about 10%. In the case of the BSMA positive ions, only the first and second classes were present. The precipitation spectra make about 20% of all event-like classes. About 45% of the event-like spectra are without precipitation, but with RH>90%, and these spectra are excluded from the further analysis. The spectra with RH<50% formed 12% of the respective classes. The established links with the …
A modelling analysis of observations of aerosol concentrations during the LAPBIAT measurement campaign is presented and possible sources of the aerosols and their precursors are discussed. The LAPBIAT measurement campaign at the SMEAR I station at …
Ambient, naturally charged small ions (<2000 Da) were measured in Hyytiala, Finland, with amass spectrometer (atmospheric pressure interface time-of-flight, APi-TOF) and two mobility spectrometers (air ion spectrometer, AIS, and balanced scanning …
This review is based on ca. 260 publications, 93 of which included data on the temporal and spatial variation of the concentration of small ions (<1.6 nm in diameter) especially in the lower troposphere, chemical composition, or formation and growth …