Dry static energy

From Glossary of Meteorology



dry static energy

(Also called the Montgomery streamfunction.) A thermodynamic variable similar to potential temperature, except that the concept of static energy assumes that any kinetic energy is locally dissipated into heat.

The amount of this dissipative heating is often negligible. When dry static energy, s, is expressed in units of kJ kg-1, the resulting values are of order 300 kJ kg-1, which reinforces the analogy with potential temperatures in units of Kelvin. Dry static energy is conserved during unsaturated vertical and horizontal motion, and is defined as
ams2001glos-De51
where cp is the specific heat capacity of air at constant pressure, T is absolute temperature, g is gravitational acceleration, and z is height. The reference height can be arbitrary; it is sometimes taken as z = 0 at P = 100 kPa to be consistent with potential temperature, or it can be defined relative to the local ground or sea level.
Compare moist static energy, liquid water static energy, saturation static energy.


Copyright 2024 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.