Geofisica pura e applicata

, Volume 43, Issue 1, pp 243–249 | Cite as

The nuclei of natural cloud formation part II: The supersaturation in natural clouds and the variation of cloud droplet concentration

  • S. Twomey


Calculations are performed to determine the time variation of supersaturation during cloud formation. It is shown that a simple expression can be used to obtain the maximum supersaturation (and hence the number of nuclei activated) as a function of updraught velocity and nucleus spectra insert omitted portion of copy reported in Part 1 and it isshown that they lead to cloud droplet concentrations which agree with those actually observed.


Time Variation Supersaturation Simple Expression Formation Part Cloud Droplet 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. (1).
    Squires P.: Aust. J. Sci. Res.A, vol. 5, 59 (1952).Google Scholar
  2. (2).
    Squires, P.: Tellus, vol. 10, 256–271 (1958).Google Scholar

Copyright information

© Istituto Geofisico Italiano 1959

Authors and Affiliations

  • S. Twomey
    • 1
  1. 1.C.S.I.R.O., Division of RadiophysicsUniversity GroundsSydneyAustralia

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