Reappraising the appropriate use of a common meteorological quantity: Potential Temperature

Published

December 15, 2020

Author(s)

Manuel Baumgartner, Ralf Weigel, Ulrich Achatz, Allan H. Harvey, Peter Spichtinger

Abstract

The potential temperature is a widely used quantity in atmospheric science since it is conserved for air's adiabatic changes of state. Its definition involves the specific heat capacity of dry air, which is traditionally assumed as constant. However, the literature provides different values of this allegedly constant parameter, which are reviewed and discussed in this study. Furthermore, we derive the potential temperature for a temperature-dependent parameterization of the specific heat capacity of dry air, thus providing a new reference potential temperature with a more rigorous basis. This new reference shows different values and vertical gradients in the upper troposphere and the stratosphere compared to the potential temperature that assumes constant heat capacity. The application of the new reference potential temperature to the prediction of gravity wave breaking altitudes reveals that the actual wave breaking height may depend on the definition of the potential temperature used.

Citation

Atmospheric Chemistry and Physics

Volume

20

Pub Type

Journals

Download Paper

https://doi.org/10.5194/acp-20-15585-2020

Local Download

Keywords

air, atmospheric modeling, entropy, heat capacity, potential temperature

Citation

Baumgartner, M. , Weigel, R. , Achatz, U. , Harvey, A. and Spichtinger, P. (2020), Reappraising the appropriate use of a common meteorological quantity: Potential Temperature, Atmospheric Chemistry and Physics, [online], https://doi.org/10.5194/acp-20-15585-2020, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929976 (Accessed April 20, 2024)