Phase instability

From Glossary of Meteorology



phase instability

The instability associated with a supercooled or supersaturated phase of matter.

A small fluctuation (on a molecular scale) or foreign particle may cause change to a more stable phase. For example, at a temperature below the equilibrium melting point of ice, the ice phase is stable, whereas liquid water is supercooled and is unstable because its chemical potential is higher than that of ice. A small fluctuation such as collision with ice may cause the supercooled water to change into ice.


Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.