This is Jim Fiorendino, your host for On the Ocean.
Clouds are composed of water and ice that has adhered to suspended particles in the atmosphere. These particles, and the clouds they help form, are capable of scattering or blocking incoming radiation from the sun and absorbing and emitting heat energy. Studying the processes that control the formation of clouds is therefore essential to our understanding of Earth’s heat budget, weather, and climate.
Cloud formation is a complex process that requires the presence of fine particles suspended in the atmosphere, known as aerosols, which serve as a surface to which water can adhere or freeze. Ice clouds appear wispy, and form high in the atmosphere, while clouds composed of water particles are fluffier and form lower in the atmosphere. Particles conducive to cloud formation are known as either cloud condensation nuclei or ice nucleation particles; the ability of these particles to promote cloud formation depends upon particle size and chemical composition. Pure water in the atmosphere will not form clouds.
The ocean and atmosphere are closely linked; understanding atmospheric processes such as cloud formation requires studying related processes occurring in the ocean. Roughly 71% of Earth’s surface is covered by water, providing a large area over which the ocean and atmosphere interact. At the interface of the atmosphere and ocean, heat, gasses, and other material are exchanged.
Waves break across the entire surface of the ocean; when waves break, droplets of water are thrown into the air. In addition to salt water, these droplets may contain microorganisms, as well as solid and dissolved organic matter. If the particles are small and light enough, they may be carried high into the atmosphere where they become cloud condensation nuclei or ice nucleating particles. Scientists in Texas A&M University’s Department of Oceanography and Department of Atmospheric Sciences are currently working to understand what role oceanic processes, particularly ocean microbiology, play in cloud formation.
This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.
Contributing Professor – Dr. Daniel Thornton