A summary of several meteorological properties of the moist-air entropy variables ${\theta }_s$ and $PV({\theta }_s)$

Abstract

The aim of this note is to describe several meteorological properties shown in a conference talk (Marquet, January 2022) for the moist-air specific entropy, the associated potential temperature (${\theta }_s$) defined in Marquet (2011) and the associated potential vorticity $PV({\theta }_s)$ defined in Marquet (2014), with in particular regions of negative values of $PV({\theta }_s)$ close to the cold fronts that seems to indicate regions of symmetric instability.

arXiv comment43 pages, 20 figures. Workshop for Forecasting and Modelling, 24th of January, 2022. Météo-France, Toulouse, France. Version-2: the email is updated; a typo is corrected in Eq.(38); and text is added in the Conclusion. Version-3: new equations (3) and (14) with the introduction of $s_0(p_0)$