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Annual and size dependent variation of growth rates and ion concentrations in boreal forest

Number size distributions of particles and ions were measured with a differential mobility particle sizer and two different ion spectrometers at the SMEAR II station in southern Finland during April 2003-April 2004. Cluster ion (diameter < 1.6 nm) …

Initial steps of aerosol growth

The formation and growth of atmospheric aerosols depend on several steps, namely nucleation, initial steps of growth and subsequent - mainly condensational - growth. This work focuses on the initial steps of growth, meaning the growth right after …

Kinetic nucleation and ions in boreal forest particle formation events

In order to gain a more comprehensive picture on different mechanisms behind atmospheric particle formation, measurement results from QUEST 2-campaign are analyzed with an aid of an aerosol dynamic model. A special emphasis is laid on air ion and …

Stable ammonium bisulfate clusters in the atmosphere

Liquid drop model based equilibrium thermodynamics predicts that in the presence of even small ammonia concentrations practically all the atmospheric sulfuric acid molecules are bound to tiny, stable ammonium-bisulfate clusters. Hitherto sulfuric …

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 (Hyytiala and Varrio in Finland and Tahkuse in Estonia) have been compared. Aerosol size distributions were measured on …

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

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 …

Observed and simulated effects of certain pollutants on small air ion spectra: I. Positive ions

The trends of the few-second-aged small positive air ion spectra caused by enhanced concentrations of certain trace gases (HCl, ammonia, HNO3, certain pyridine derivatives, (CH3)(2)SO, (C4H9)(3)N, C6H5CHO, CH3CN) have been studied. The measurements …

Methods for imputation of missing values in air quality data sets

Reversible work of the formation of a layer of a new phase on a spherical charged conductor within a uniform multicomponent macroscopic mother phase

A thermodynamically consistent formalism is applied to calculate the reversible work needed to form a small layer of a new phase (embryo) around a charged insoluble conducting sphere within a uniform macroscopic mother phase. To treat the embryos of …

Diurnal variation in the concentration of air ions of different mobility classes in a rural area

Analyzed data consist of 8900 hourly average mobility distributions measured in the mobility range of 0.00041-3.2 cm(2) V(-)1 s(-1) ( diameter range 0.36-79 nm) at Tahkuse Observatory, Estonia, in 1993-1994. The average diurnal variation in the …