Aitken nucleus

meteorology

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 18, 2026

Quick Summary

An Aitken nucleus is a microscopic aerosol particle found in the atmosphere. These particles are crucial in meteorology because they encourage water vapor to condense, forming droplets that can lead to clouds and fog.12

While there are even smaller nuclei in the atmosphere, Aitken nuclei are significant because they facilitate condensation under normal atmospheric conditions. These tiny particles, named after Scottish meteorologist John Aitken, play a vital role in atmospheric processes. They can be produced by natural sources like fires and ocean wave action, as well as by human activities.312

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

3 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

condensation nucleus
…nuclei in the atmosphere, called Aitken nuclei, but they ordinarily play no role in cloud formation because they do not induce condensation unless the air is highly supersaturated with water vapour. Nuclei that have diameters of several microns and are composed of a hygroscopic, or moisture-attracting, substance (e.g., sea salt)…
Read More
…nuclei in the atmosphere, called Aitken nuclei, but they ordinarily play no role in cloud formation because they do not induce condensation unless the air is highly supersaturated with water vapour. Nuclei that have diameters of several microns and are composed of a hygroscopic, or moisture-attracting, substance (e.g., sea salt)…
Read More

aerosol
…are sometimes referred to as Aitken nuclei.
Read More
…are sometimes referred to as Aitken nuclei.
Read More

John Aitken
…that microscopic particles, now called Aitken nuclei, play in the condensation of atmospheric water vapour in clouds and fogs. Ill health prevented Aitken from holding any official position; he worked instead in the laboratory in his home in Falkirk. Much of his work was published in the journals of the…
Read More
…that microscopic particles, now called Aitken nuclei, play in the condensation of atmospheric water vapour in clouds and fogs. Ill health prevented Aitken from holding any official position; he worked instead in the laboratory in his home in Falkirk. Much of his work was published in the journals of the…
Read More