Cosmic rays can help produce aerosol particles which foster cloud buildup but they are not likely to be a major presence in the atmosphere, according to a study published in the journal Nature.
The study was based on findings from the European Organisation for Nuclear Research (CERN)'s CLOUD experiment, which uses a cloud chamber to study possible associations between galactic cosmic rays and cloud formation.
Cosmic rays are charged particles that enter the Earth's atmosphere from outer space. They could affect the amount of cloud covering the Earth through the formation of new aerosols - tiny particles that help cloud droplets to form.
Changes in cloud cover of just a few percent have been shown to have an important effect on the world's climate.
The Nature study of the CLOUD experiment's results found that, through the influence of sulphuric acid, ionisation could enhance the rate of water droplet growth at certain temperatures.
“(...) It could be quite large when averaged globally over the troposphere,” said the Nature study.
“However, the fraction of these freshly nucleated particles that grow to sufficient sizes to seed cloud droplets ... remain open questions experimentally,” it added.
“These are important findings for the potential link between galactic cosmic rays and clouds.”
