Sentences with phrase «nucleation rate of»

We find that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100 — 1,000-fold.

They find that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume increase the nucleation rate of sulphuric acid particles by more than a factor of 100 to 1,000.

the homogeneous nucleation rate of drops nucleation in supersaturated vapor (Eqn.

► Ions enhance the nucleation rate of stable clusters and the initial growth rate.

«Ground - level GCR ionization substantially increases the nucleation rate of sulphuric acid and sulphuric acid — ammonia particles, by between twofold and tenfold or more, provided that the nucleation rate lies below the limiting ion - pair production rate.»

Not exact matches

«If there is too little of either component then nucleation will not occur at an appreciable rate in the low atmosphere,» says Kirkby.

By performing experiments in the precisely controlled environment of the CLOUD chamber, the project's scientists can change the concentrations of chemicals involved in nucleation and then measure the rate at which new particles are created with extreme precision.

Although scientists have observed that the nucleation process nearly always involves sulfuric acid, sulfuric acid concentrations aren't high enough to explain the rate of new particle formation that occurs in the atmosphere.

A paper discussing the difficulty of getting from nm sized nucleation mode to a size that can generate cloud particles is: Erupe, M. E., et al. (2010), Correlation of aerosol nucleation rate with sulfuric acid and ammonia in Kent, Ohio: An atmospheric observation, J. Geophys.

The suggestion from the text is that nucleation rates obey Boltzmann statistics generally but in certain conditions of high surfactant loads and low tempertures the governing rates have Bose - Einstein statistics.

«In addition we demonstrate that the binary H2SO4 — H2O nucleation scheme, as it is usually considered in modeling studies, underestimates by 7 to 8 orders of magnitude the observed particle formation rate and, therefore, should not be applied in tropospheric conditions.»

The variability of atmospheric ionization rates due to GCR changes can be considered relatively well quantified (Bazilevskaya et al., 2008), whereas resulting changes in aerosol nucleation rates are very poorly known (Enghoff and Svensmark, 2008; Kazil et al., 2008).

A high - voltage clearing field could also be used to remove all ions from the CLOUD chamber, meaning that the neutral nucleation rate could be measured and compared with nucleation enhanced by the presence of ions.

100 ppt of ammonia led to a 100 — 1000-fold increase in the nucleation rate, while ground - level cosmic ray intensities were found to increase the nucleation rate by up to a factor of 10 (Kirkby et al. 2011).

This lowers the probability that the particles will survive to CCN sizes, and as a result it reduces the sensitivity of CCN concentrations to changes in the nucleation rate (Pierce & Adams 2009).

In the article «Global atmospheric particle formation from CERN CLOUD measurements,» sciencemag.org, 49 authors concluded «Atmospheric aerosol nucleation has been studied for over 20 years, but the difficulty of performing laboratory nucleation - rate measurements close to atmospheric conditions means that global model simulations have not been directly based on experimental data.....

The CERN CLOUD measurements are the most comprehensive laboratory measurements of aerosol nucleation rates so far achieved, and the only measurements under conditions equivalent to the free and upper troposphere.»

Ions increase the nucleation rate by an additional factor of between two and more than ten at ground - level galactic - cosmic - ray intensities, provided that the nucleation rate lies below the limiting ion - pair production rate.

Model calculations suggest that almost half of the global cloud condensation nuclei in the atmospheric boundary layer may originate from the nucleation of aerosols from trace condensable vapours4, although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small5, 6.

However, even with the large enhancements in rate due to ammonia and ions, atmospheric concentrations of ammonia and sulphuric acid are insufficient to account for observed boundary - layer nucleation.

Even with the large enhancements in rate caused by ammonia and ions, they conclude that atmospheric concentrations of ammonia and sulphuric acid are insufficient to account for observed boundary layer nucleation.

He ignores the possibility that decadal variability may be caused by external forcing such as cosmic rays which are known to cause increased rates of aerosol nucleation.