Capillary action

From Glossary of Meteorology



capillary action

The depression or elevation of the meniscus of a liquid contained in a tube of small diameter due to the combined effects of gravity, surface tension, and the forces of cohesion and adhesion.

When the liquid wets the walls of a container, the meniscus is shaped convex downward; if the liquid does not wet the walls of the container, the meniscus is shaped convex upward.