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An evaluation and comparison of cloud condensation nucleus activity models: Predicting particle critical saturation from growth at subsaturation

Rissler, Jenny; Svenningsson, Birgitta LU ; Fors, Erik LU ; Bilde, Merete and Swietlicki, Erik LU (2010) In Journal of Geophysical Research 115.
Abstract
The ability of particles to activate and form cloud droplets influences the functioning of the Earth's hydrological cycle. This work links the particle water uptake at subsaturation to the critical supersaturation ratio needed for particles to become cloud condensation nuclei (CCN). Five models using the particle hygroscopic growth at subsaturation for predicting the critical supersaturation needed for droplet activation were applied to a laboratory data set of inorganic and organic compounds and mixtures of them. The data set consisted of hygroscopicity tandem differential mobility analyzer measurements and CCN counter measurements. No chemical composition information was used when applying the models. All models tested were based on... (More)
The ability of particles to activate and form cloud droplets influences the functioning of the Earth's hydrological cycle. This work links the particle water uptake at subsaturation to the critical supersaturation ratio needed for particles to become cloud condensation nuclei (CCN). Five models using the particle hygroscopic growth at subsaturation for predicting the critical supersaturation needed for droplet activation were applied to a laboratory data set of inorganic and organic compounds and mixtures of them. The data set consisted of hygroscopicity tandem differential mobility analyzer measurements and CCN counter measurements. No chemical composition information was used when applying the models. All models tested were based on modifications of Kohler theory and gave similar results. The agreement between predicted and measured critical supersaturations was good, considering the relatively simple models used. A trend of overestimating the critical supersaturations was observed, typically by similar to 15%. The best performing model gave on average only a 4% offset from experimental values; the model with the largest deviation was offset by 20%. A comparison was made between the number of soluble entities (ions or nondissociating molecules) estimated from the particle hygroscopic growth at 90% relative humidity (RH) and the number estimated from the particle critical supersaturation; a similar to 35% increase was observed in the effective number of entities in solution when going from 90% RH to activation. For many types of aerosols, differences in the model approaches tested do not induce large differences in the predicted critical supersaturation. However, it is most important to follow the recommendations published with the respective models and not use them indiscriminately. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Geophysical Research
volume
115
publisher
American Geophysical Union
external identifiers
  • wos:000284704400008
  • scopus:78649494489
ISSN
2156-2202
DOI
10.1029/2010JD014391
project
MERGE
language
English
LU publication?
yes
id
fcc1d6c5-ac43-4795-ac22-71136bf30b56 (old id 1752144)
date added to LUP
2010-12-29 17:55:49
date last changed
2018-05-29 11:15:28
@article{fcc1d6c5-ac43-4795-ac22-71136bf30b56,
  abstract     = {The ability of particles to activate and form cloud droplets influences the functioning of the Earth's hydrological cycle. This work links the particle water uptake at subsaturation to the critical supersaturation ratio needed for particles to become cloud condensation nuclei (CCN). Five models using the particle hygroscopic growth at subsaturation for predicting the critical supersaturation needed for droplet activation were applied to a laboratory data set of inorganic and organic compounds and mixtures of them. The data set consisted of hygroscopicity tandem differential mobility analyzer measurements and CCN counter measurements. No chemical composition information was used when applying the models. All models tested were based on modifications of Kohler theory and gave similar results. The agreement between predicted and measured critical supersaturations was good, considering the relatively simple models used. A trend of overestimating the critical supersaturations was observed, typically by similar to 15%. The best performing model gave on average only a 4% offset from experimental values; the model with the largest deviation was offset by 20%. A comparison was made between the number of soluble entities (ions or nondissociating molecules) estimated from the particle hygroscopic growth at 90% relative humidity (RH) and the number estimated from the particle critical supersaturation; a similar to 35% increase was observed in the effective number of entities in solution when going from 90% RH to activation. For many types of aerosols, differences in the model approaches tested do not induce large differences in the predicted critical supersaturation. However, it is most important to follow the recommendations published with the respective models and not use them indiscriminately.},
  author       = {Rissler, Jenny and Svenningsson, Birgitta and Fors, Erik and Bilde, Merete and Swietlicki, Erik},
  issn         = {2156-2202},
  language     = {eng},
  publisher    = {American Geophysical Union},
  series       = {Journal of Geophysical Research},
  title        = {An evaluation and comparison of cloud condensation nucleus activity models: Predicting particle critical saturation from growth at subsaturation},
  url          = {http://dx.doi.org/10.1029/2010JD014391},
  volume       = {115},
  year         = {2010},
}