A summary of several meteorological properties of the moist-air entropy variables $\theta_s$ and $PV(\theta_s)$

TL;DR

This paper reviews meteorological properties of moist-air entropy, focusing on potential temperature and potential vorticity, highlighting their behavior near cold fronts and implications for symmetric instability.

Contribution

It summarizes key properties of $ heta_s$ and $PV( heta_s)$, emphasizing their significance in understanding atmospheric stability and dynamics.

Findings

Regions of negative $PV( heta_s)$ near cold fronts suggest symmetric instability.

Properties of $ heta_s$ help in diagnosing atmospheric stability.

Potential vorticity $PV( heta_s)$ varies significantly across different meteorological conditions.

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.